System warm-up

[James Harris]

Hi,

My hi-fi sounds great sometimes and not others. I am told that it needs an hour's warm-up
and this could fit with the times it has sounded good. For example, great one evening but
poor the next morning. I leave the electronics on but not playing.

Is there a CD that can be played to loosen the system up? I suspect the speakers most.
Bass extension is particularly absent at times. Any suggestions as to whether playing a
very low frequency sine wave or similar could do the trick?

--
TIA,
James

[Arny Krueger]

James Harris wrote:


> My hi-fi sounds great sometimes and not others.

Most likely causes would be your state of mind and your selection of music
to listen to.

> I am told that it
> needs an hour's warm-up and this could fit with the times it has
> sounded good.

If your system has some technical defect, then warming up could deal with
the problem. In general audio systems are up to peak performance within a
minute or less of commencment of use.

>For example, great one evening but poor the next
> morning.

Your system could have a defect that makes it extraordinarly sensitive to
operating temperature.

> I leave the electronics on but not playing.

> Is there a CD that can be played to loosen the system up?

Nothing special should be required.

>I suspect the speakers most. Bass extension is particularly absent at
times.

In fact, the cause could be anything else in the system.

> Any suggestions as to whether playing a very low frequency sine wave
> or similar could do the trick?

Not if your system is in good shape.

[S888Wheel]

>From: "James Harris" no.email.please
>Date: 4/13/2004 4:06 PM Pacific Standard Time
>Message-id: >
>
>Hi,
>
>My hi-fi sounds great sometimes and not others. I am told that it needs an
>hour's warm-up
>and this could fit with the times it has sounded good. For example, great one
>evening but
>poor the next morning. I leave the electronics on but not playing.
>

Maybe you could give us the specifics on your system.

>
>Is there a CD that can be played to loosen the system up? I suspect the
>speakers most.
>Bass extension is particularly absent at times. Any suggestions as to whether
>playing a
>very low frequency sine wave or similar could do the trick?
>

Check Acoustic Sounds or Music Direct for a number of test and diagnostic CDs.
I doubt that Bass extension would be that affected by any sort of warm up.

[Woody]

"Arny Krueger" > wrote in message
...
> James Harris wrote:
>
>
> > My hi-fi sounds great sometimes and not others.
>
> Most likely causes would be your state of mind and your selection of music
> to listen to.
>
> > I am told that it
> > needs an hour's warm-up and this could fit with the times it has
> > sounded good.
>
> If your system has some technical defect, then warming up could deal with
> the problem. In general audio systems are up to peak performance within a
> minute or less of commencment of use.
>
> >For example, great one evening but poor the next
> > morning.
>
> Your system could have a defect that makes it extraordinarly sensitive to
> operating temperature.
>


More like changes in your hearing. Have you ever noticed that you set your
clock-radio in sleep mode and go to sleep listening to the news or whatever
fairly quietly, but when it wakes you in the morning it is deafeningly loud?

Your hearing is done by a 'field' of very fine hairs inside your ear canal
that flex with the air movement that we call sound. During the day ambient
noise, from traffic, being inside a moving car/train/plane, and/or workplace
noise, etc etc cause the hairs to get tired and somewhat slow to move -
rather like a lawn on which the kids have been playing all day - so your
hearing sensitivity decays. Whilst you sleep in a relatively quiet
environment the hairs rejuvenate so that come the morning your hearing is
vastly more sensitive - the grass perks up again. The hairs also deplete in
quantity and flexibility with age, hence why in most people high frequency
sensitivity decays as you get older. Deafness, especially that induced by
working in a high-moise environment with protection, occurs when the hairs
stay tired and cannot restore themselves - i.e. the grass has had neither
food or water and stays 'flat.'

In terms of hi-fi, in the morning you probably don't play it quite so loud
which affects both how the speaker sounds in itself and how it interacts
with the room, thus affecting the subjective sound quality.

Subjectivity is by definition opinion, so how you hear something may and
most probably differ from how someone else hears it and hence why I think,
for example, that the Wharfedale 8.3 is awful, but What Hi-Fi think it is
the best thing since sliced bread!


--

Woody

[Robert Morein]

"Woody" > wrote in message
...
>
> "Arny Krueger" > wrote in message
> ...
> > James Harris wrote:
> >
> >
> > > My hi-fi sounds great sometimes and not others.
> >
> > Most likely causes would be your state of mind and your selection of
music
> > to listen to.
> >
> > > I am told that it
> > > needs an hour's warm-up and this could fit with the times it has
> > > sounded good.
> >
> > If your system has some technical defect, then warming up could deal
with
> > the problem. In general audio systems are up to peak performance within
a
> > minute or less of commencment of use.
> >
> > >For example, great one evening but poor the next
> > > morning.
> >
> > Your system could have a defect that makes it extraordinarly sensitive
to
> > operating temperature.
> >
>
>
> More like changes in your hearing. Have you ever noticed that you set your
> clock-radio in sleep mode and go to sleep listening to the news or
whatever
> fairly quietly, but when it wakes you in the morning it is deafeningly
loud?
>
My ears are literally congealed in the morning. As the day wears on, they
loosen up.
The tissues of the ears live in a world of thick, goopy liquid, the
consistency of which varies from hour to hour and day to day.

[Mike Gilmour]

"James Harris" <no.email.please> wrote in message
.. .
> Hi,
>
> My hi-fi sounds great sometimes and not others. I am told that it needs an
hour's warm-up
> and this could fit with the times it has sounded good. For example, great
one evening but
> poor the next morning. I leave the electronics on but not playing.
>
> Is there a CD that can be played to loosen the system up? I suspect the
speakers most.
> Bass extension is particularly absent at times. Any suggestions as to
whether playing a
> very low frequency sine wave or similar could do the trick?
>
> --
> TIA,
> James
>
>

My hi-fi sounds great late night and during the early hours... single malt
may have a lot to do with it ;-)

[Powell]

"James Harris" wrote

> My hi-fi sounds great sometimes and not others. I am
> told that it needs an hour's warm-up and this could fit
> with the times it has sounded good. For example, great
> one evening but poor the next morning. I leave the
> electronics on but not playing.
>
Perhaps you might consider a power line conditioner.
These devices reduce RF, EMI and other distortions
that leak into your hi-fi gear from AC power lines.
While some equipment does not appear (sound
wise) to benefit from the device most will, IME.

Most audio stores will allow you to demo these
devices for free so there is no financial risk. The cost
of these units start at $200 and run up to $4,000
depending on your needs. For a periodical review of
these units check out Stereophile issue Vol. 17 No.
12.


> Is there a CD that can be played to loosen the
> system up? I suspect the speakers most. Bass
> extension is particularly absent at times. Any
> suggestions as to whether playing a very low
> frequency sine wave or similar could do the trick?
>
Yes, they are commonly referred to as break-in or
system burn-in CD’s. They range from highly
specialized (Purest Audio Design System Enhancer,
$110) to a single track on a test CD (Cardas/Ayre
System Enhancement Disk, $20 or XLO/Reference
Recordings Test and Burn-In CD, $27).

[Dave Plowman]

In article >,
Powell > wrote:
> Most audio stores will allow you to demo these devices for free so there
> is no financial risk. The cost of these units start at $200 and run up
> to $4,000 depending on your needs.

For a few chokes and capacitors at most? Some people have more money than
sense. Better to buy equipment where the maker has catered for possible
mains borne interference.

> For a periodical review of these units check out Stereophile issue Vol.
> 17 No. 12.

Love to know how you arrange for a 'dirty' mains supply to be anything
like typical.

--
*Eat well, stay fit, die anyway

Dave Plowman London SW 12
RIP Acorn

[Fleetie]

"Mike Gilmour" > wrote
> My hi-fi sounds great late night and during the early hours... single malt
> may have a lot to do with it ;-)

Beer googles for the ears?


Martin
--
M.A.Poyser Tel.: 07967
110890
Manchester, U.K.
http://www.fleetie.demon.co.uk

[Powell]

"Dave Plowman" wrote

> > Most audio stores will allow you to demo these devices
> > for free so there is no financial risk. The cost of these
> > units start at $200 and run up to $4,000 depending on
> > your needs.
>
> For a few chokes and capacitors at most?
>
For example, better designs might include having isolated
transformers, balanced design technology, regeneration of
the wave form, outlet isolation/open ground, provide for
special need of source/power amps just to prevent
electrical grid injection noise.


> Some people have more money than sense. Better to
> buy equipment where the maker has catered for possible
> mains borne interference.
>
And, some people have bad credit (no plastic) which
prevents them from trying a free demo unit in their home
setup. Or they don’t know any better. Which are you?


> > For a periodical review of these units check out
> > Stereophile issue Vol. 17 No. 12.
>
> Love to know how you arrange for a 'dirty' mains supply
> to be anything like typical.
>
Consider doing your own home work (empirical experience).

[Dave Plowman]

In article >,
Powell > wrote:
> > For a few chokes and capacitors at most?
> >
> For example, better designs might include having isolated
> transformers, balanced design technology, regeneration of
> the wave form, outlet isolation/open ground, provide for
> special need of source/power amps just to prevent
> electrical grid injection noise.

You must be referring to US stuff. All UK equipment already has an
isolating transformer. It would be illegal to sell one without.


> > Some people have more money than sense. Better to
> > buy equipment where the maker has catered for possible
> > mains borne interference.
> >
> And, some people have bad credit (no plastic) which
> prevents them from trying a free demo unit in their home
> setup. Or they don<t know any better. Which are you?

I know that you're advocating the spending of money that isn't needed.
Just buy decent equipment in the first place.


> > > For a periodical review of these units check out
> > > Stereophile issue Vol. 17 No. 12.
> >
> > Love to know how you arrange for a 'dirty' mains supply
> > to be anything like typical.
> >
> Consider doing your own home work (empirical experience).

So I take it you just do 'subjective' testing then? Figures.

--
*Change is inevitable ... except from vending machines *

Dave Plowman London SW 12
RIP Acorn

[Woody]

"Powell" > wrote in message
...
>
> "Dave Plowman" wrote
>
> > > Most audio stores will allow you to demo these devices
> > > for free so there is no financial risk. The cost of these
> > > units start at $200 and run up to $4,000 depending on
> > > your needs.
> >
> > For a few chokes and capacitors at most?
> >
> For example, better designs might include having isolated
> transformers, balanced design technology, regeneration of
> the wave form, outlet isolation/open ground, provide for
> special need of source/power amps just to prevent
> electrical grid injection noise.
>
>
> > Some people have more money than sense. Better to
> > buy equipment where the maker has catered for possible
> > mains borne interference.
> >
> And, some people have bad credit (no plastic) which
> prevents them from trying a free demo unit in their home
> setup. Or they don’t know any better. Which are you?
>
>
> > > For a periodical review of these units check out
> > > Stereophile issue Vol. 17 No. 12.
> >
> > Love to know how you arrange for a 'dirty' mains supply
> > to be anything like typical.
> >
> Consider doing your own home work (empirical experience).
>
>
>
>

Note to UK readers - they're not all locked up yet!

[Ian Bell]

"James Harris" <no.email.please> wrote:

> Hi,
>
> My hi-fi sounds great sometimes and not others. I am told that it needs an
> hour's warm-up and this could fit with the times it has sounded good. For
> example, great one evening but poor the next morning. I leave the
> electronics on but not playing.
>
> Is there a CD that can be played to loosen the system up? I suspect the
> speakers most. Bass extension is particularly absent at times. Any
> suggestions as to whether playing a very low frequency sine wave or
> similar could do the trick?
>

Hi-fi loudspeakers are well known to change after playing some time as the
voice coil heats up. If you can hear the difference perhaps it is time to
invest in some monitor speakers instead. They tend to use heavier gauge
voice coil windings and are better at removing heat from them too.

Ian

Ian

[Powell]

"Dave Plowman" wrote

> > > For a few chokes and capacitors at most?
> > >
> > For example, better designs might include having isolated
> > transformers, balanced design technology, regeneration of
> > the wave form, outlet isolation/open ground, provide for
> > special need of source/power amps just to prevent
> > electrical grid injection noise.
>
> You must be referring to US stuff. All UK equipment
> already has an isolating transformer. It would be illegal
> to sell one without.
>
Please re-read the above paragraph. It’s “transformers”...
that means plural in English.

plural >adjective 1 more than one in number. 2 Grammar
(of a word or form) denoting more than one.

Here’s and example of the of the design I use.
http://www.audiopower.com/newsite/toc.html


> > > Some people have more money than sense. Better to
> > > buy equipment where the maker has catered for possible
> > > mains borne interference.
> > >
> > And, some people have bad credit (no plastic) which
> > prevents them from trying a free demo unit in their home
> > setup. Or they don<t know any better. Which are you?
>
> I know that you're advocating the spending of money
> that isn't needed.
>
How would you know?


> Just buy decent equipment in the first place.
>
Quack, quack, quack...


> > > > For a periodical review of these units check out
> > > > Stereophile issue Vol. 17 No. 12.
> > >
> > > Love to know how you arrange for a 'dirty' mains supply
> > > to be anything like typical.
> > >
> > Consider doing your own home work (empirical experience).
>
> So I take it you just do 'subjective' testing then? Figures.
>
Sure, you can demo one and find out for yourself.... depending
on your financial limitations.

For your edification, Mr. Plowman:

Nigel's Power Line Conditioner Info Sheet
(C) 2000

V 1.15
This document may be copied so long as it is copied in it's
entirety, including copyright, and so long as it is not posted to
rec.audio.high-end

Sections:

I. What IS a Power Line Conditioner?
II. Why do I NEED/WANT one?
III. HTML Links
IV. Specific Products & Technology
V. Cheap Tweaks for the Dangerously Inclined
VI. Closing Comments

I. What IS a Power Line Conditioner?
=====================================
Before there was such a market for high end tweaks and buzz words in high
end audio/video companies like APCC & Tripplite among many others were
already making power conditioners for the computer and electronics industry.
These devices are still made and they are used to provide voltage regulation
for devices like copiers. They used transformers with multiple taps, and as
the input voltage surges or sags the relays or transistors in the power
conditioner would switch among the different transformer taps. I thought
Tice
or Audio Power made a similar device, but I seem to be mistaken. Two good
sources of non- esoteric power line conditioners are www.furmasound.com
and www.equitech.com. Pretty good looking stuff if you have common
surge/sagging problems.

Today there are many things called a line conditioner, and they are not all
the same. In general a power line conditioner can be everything from a
power strip with surge protection to larger, beefy boxes that do a variety
of things to the incoming AC power.

A line conditioner may have some features to do the following:

1. Filter the AC signal so you get closer to
an ideal 60 Hz signal.
2. Provide surge protection
3. Provide Under / Over voltage protection
(turns off)
4. Provide Under / Over voltage regulation
(keeps the output voltage constant)
5. Provide power outage protection
(like an Uninterruptable Power Supply)
6. Provide a lower apparent impedance to the source
(like PS Audio, Elgar, etc.)

Different products work differently, and will have different feature mixes.
The heavier, the more you are paying for, so beleive it or not the cost per
pound is a good indicator of how much is going into the product, and a
good guage of how much you should be paying for it. If you just spent
$1,300 on a power strip you can pick up with your pinky, you paid too
much. Articles in Hi Fi News and Record Review (a brit mag) in 1998-99
give some insight into building your own.

Alas not all filtration is the same. Products which claim to filter RFI/EMI
only start to work at around 100 kHz or higher, which is far above human
audibility. The theoretically ideal power line filter would filter out all
signals below and above 60 Hz.

II. Why do I NEED/WANT one?
============================
II.a: NEEDS
Unless you suffer from chronic over/under voltages at your house then
chances are you don't really need a power conditioner, the system will work
reliably without it.

You may very well find that surge protection is important to you. Check out
the separate "Nigel's Surge Supression Info Sheet".

If you're buying some fancy power line conditioner that is supposed to
include surge protection, ask them if the equipment has been certified to
UL 1449 Second Edition. I have yet to see an audio equipment
"Conditioner" manufacturer that claims surge supression publish any
sort of UL or CSA listing on their web site, so be careful about relying on
them for surge supression. This does not include Monster Cable's strips,
they are primarily a surge supressor, with noise filters added, and are in
fact UL 1449 certified.

II.b: WANTS
Audio/videophiles WANT power conditioners because they feel it will improve
the quality of their listening or viewing experience. How much of an
audible or visible difference a power line conditioner will make in your
world depends on the following:

1. The quality of your incoming AC power.
2. The quality of your components power supplies.
3. The resolution of your system
(Fix your room acoustics first, then
worry about power line issues)
4. The effectiveness & features of the
line conditioner.
5. How much noise the line conditioner itself
actually creates
(a potential problem in a UPS)
6. What frequencies the power conditioner's filtration
is effective at.
7. Your gullibility

An example of exceptional power supply design is found in much of Krell and
Mark Levinson equipment some of which use fully regulated, fully balanced
power supplies. This is a rare thing, but any potential benefit from a
power conditioner may be a mute point with this
equipment. Most amplifiers use unregulated, but highly filtered power
supplies, relying on the incoming AC voltage remaining constant, and large
capacitors to reduce any noise on the line.

II.c: WON'Ts
One thing most line conditioners don't do is fix ground loop problems (i.e.
a loud 60 Hz hum you hear coming from your speakers), in some cases they
can actually make things worse by improving the connection to ground of
your equipment. The ideal way to fix a ground loop problem is to use signal
level isolation transformers between your system and the source of the
problem, which is often the cable TV or a computer connection. Check out:

www.jensentransformers.com

for a variety of safe solutions. Otherwise, if you want to start a fire or
electrocute yourself or your family, use a 2-3 prong adaptor, a.k.a. a
cheater plug.

There is one exception to this. Power conditioners that provide balanced
outputs may reduce ground loop related hums, as well as provide a good
lowering of the overall noise floor.

Also, power conditioners should not be used to substitute for bad electrical
wiring. In some cases a power conditioner may make things worse, drawing
more current and stressing the existing wiring. You should NEVER over fuse

wiring.

III. HTML Links
================
Here is a variety of links to people selling things that go between your
equipment and the incoming AC line.

www.apcc.com
www.audiopower.com
www.accuphase.com
www.belkin.com
www.bestpower.com
www.brickwall.com
www.elgar.com
www.equitech.com
www.furmasound.com
www.monstercable.com
www.psaudio.com
www.surgex.com
www.ticeaudio.com
www.tripplite.com
www.vansevers.com

You should also check the links from www.stereophile.com which
seem to be pretty exhaustive, and mention many more manufacturer links
to audio related power line products than I do here. Be warned however
that while the list at Stereophile may be more comprehensive than mine,
it's less discriminating, and includes some products I feel provide
particularly poor return on investment.

IV. Products & Technology
==========================
Some products merit special attention in my book, for a variety of reasons.

Monster Cable
=============
Despite having the WORST web site in all of audio regarding technology, with
gross technical and gramatical errors, several people have sent me e-mails
defending their power strips, claiming they made improvements in picture or
video quality. Heck if I know, but you might want to, they're not too
expensive.

Panamax
=======
Panamax gets special because they do have complete A/V surge protection
solutions their parts quality does not usually merit what they charge, like
$99 for a standard surge strip, and I've read of reliability and warranty
problems online, so you should check the archives at
www.deja.com. In my opinion APCC, Triplite and Belkin all give you
more surge protection/dollar than Panamax.

The Panamax DBS+ I have (got a deal on it) has failed to protect my two
satelite receivers from wind related static discharge , so I'm not too happy
with them these dayas.

Brickwall & Zerosurge
=====================
Working on a completely different principle of surge protection than MOV
based surge protectors are the models from Brick Wall and
ZeroSurge. They are basically single pole low pass filters ( a good thing )
for your power lines. The claimed response is -3db at 3 kHz. This
effectively limits the maximum Volts/Second. When a surge hits, it becomes
a 2nd and 3rd order low pass filter. Surgex also OEM's these devices, or
licenses the technology.

This low start point for their noise filtration puts them into both my Line
Conditioner sheet as well as my Surge Protection sheet.

Audo Power & Tice
=================
Moving closer to the ideal of a power line conditioner are the ones that
use isolation transformers. These have a much better capacity to remove
audible power line noise than mere surge strips. Audio Power & Tice have
a variety of products you should take a listen to, if you can get past
Tice's
voodoo web pages (i.e. their Q&A section). Note that not all these
products use isolation transformers, so check to be sure what you're
getting.

Richard Gray's Power Company
============================
Tremendous hype on their web site is parroted almost word for word by
dealers and customers. Their web site and "Grey Paper" fails to make any
truly technical statements about what the product does and IMHO they offer
poor return on investment, considering the parts that actually go into them,
and that they sell for around $700. I would encourage people to either
spend another $300 for a PS Audio unit, or spend less for something from
Furmasound or Equitech, or even getting a power conditioner (not a UPS)
from APC or Tripp Lite instead of buying a product from this company.

PS Audio
========
New are the Power Plant models from PS Audio. PS Audio has taken the
high road, and said electrical bill be damned! We'll get clean power no
matter the cost. The Power Plant models are basically power amplifiers
that re-create the 115 Volt AC signal at their output. They are perhaps the
most ambitious designs I've seen so far and again have some good ideas
behind them. Their prices seem very reasonable, considering how much
goes into one and the current offerings of power conditioners in the
market, and they certainly should be able to meet their twin goals of:

Greatly reducing apparent power line impedance

- AND -

Greatly reducing power line noise and distortion

The technology used may very well be the best at doing those two things
in combination.

Since the Power Plants are essentially class AB amplifiers they are no
better than 50% efficient, so expect it to add additional heat and
electrical current draw to your electric circuit, which is something to pay
attention to if you're close to being overloading it already. On the other
hand, using a linear (AB) amplifier stage removes the likelihood of
more digital noise being introduced into the 60 Hz waveform it
generates.

If the PS Audio units don't have enough current capacity, consider the
products from Elgar, sweeet....way expensive! If you have money to burn,
perhaps you should consider an Elgar as a pre-conditioner, and use a PS
Audio unit for your source components only.

Other equipment manufacturers should also take note that unlike many sites
PS Audio's web site was delightfully free of bovine scatalogical samples.

Chang Lightspeed
================
Chang Lightspeed need comments on because of their on-line
advertising which demonizes coils & transformers. They're right about
small, poorly designed coils actually increasing the power line
impedance, however what they fail to note is that by going coilless their
conditioners may very well not be able to remove any power line noise
within the audible spectrum. This noise is the most important to
audiophiles are concerned with as it has the best chance of being
propagated through the power supplies of the equipment and finally
to our ears. Perhaps this is why their on-line advertising mentions
RFI/EMI noise reduction so much, and makes no mention of audio
frequency noise reduction. Coil impedance can be overcome by using
bigger and better inductors.

Does anyone know how much these puppies weigh? I bet you they're
lighter and are less expensive to manufacture than comparative
products from manufacturers who DO use coils in their designs.

Uninterruptable Power Supplies
==============================
A UPS is a must for anyone doing serious computer work, but it's benefits
for audiophiles will vary. If you're going to try a UPS to improve the
sound / picture quality then avoid the standby kind, which have a 2-4 ms
lag before they turn on. Get one labeled "line interactive."

Because UPS's are designed for computers they usually pay little attention
to how much grunge is coming out when they generate the output
waveform, which could in turn easily make your system sound worse,
not better. The solution is to make sure the output of your UPS is a sine
wave, with the lowest possible distortion and noise. So, avoid "stepped
aproximation" and look for "pure sinewave" output.

Lastly, most UPS have a relatively loose voltage regulation. For example,
as the input voltage varies from 90 to 145 volts the UPS will output from
105 to 125 volts. It's a smaller variation than what's coming in, and it's
certainly better than any passive conditioners like Audio Power or Tice but
it's certainly not the best technology could do if money were no object.

Radio Shack
===========
Yes, RS can be an audiophiles best friend, especially when he/she is
looking for a $20 voltage meter. If you think you have a chronic voltage
problem at your home or listening room outlets go get a meter and find
out. If it's bad enough, perhaps you should start with a phone call to your
electrical company and/or electrician before getting a voltage conditioner.

V. Cheap Tweaks for the Dangerously Inclined
=============================================
One potential improvement audiophiles can make, fairly easily if they are
electronically and dangerously inclined, is to increase the power supply
filter capacitance. You can do this both by replacing the current storage
capacitors to higher values of capacitance (and equal or better voltages)
and also by adding storage capacitance across the maximum + and -
voltage rails of the device (make sure the capacitor's voltage rating is
greater than the difference between the + and - rails, of course). While
we're going there, consider also replacing the filter caps with less
inductive versions if possible such as caps from Sanyo or Panasonic
(I think, sorry, it's been a while since I was opening data books so check
this out yourself) as well as adding polypropelyne or polystyrene
capacitors of equal or greater voltage rating in parallel with any upgrades
you do.

Be careful with how much capacitance you add, adding capacitance
increases the turn on (inrush) current and may over-stress the bridge
rectifier. Of course, the fix for this is to add a bigger rectifier so you
can get
more power! (Grunt grunt!) And if you fry your transforer too, well that can
be fixed as well!

This little tweak alone can greatly increase the S/N ratio of many mass
market electronic devices far more than other tweaks, such as new power
cables. If you already have a very good power supply it won't matter much
as if you didn't (i.e. it will make a bigger difference for mass market Sony
or Yamaha than Krell or Mark Levinson).

I won't go into any more detail than this, if you have to ask chances are
you shouldn't be in there anyway. Oh, yeah, and as always, if you're an
idiot and hurt yourself or your equipment don't call me, have your mama
call me so I can tell her what a dufus you are.

VI. Closing Comments
=====================
I don't mean to exclude anyone, so if I missed you or a product you feel
deserves special mention send an e-mail to nigel_tufnel@my- deja.com
and I'll add it onto this growing and improving list.

As always, thoughtful, informative discussions are encouraged,
corrections are gladly accepted, and flames may be sent to
. It's your ears, eyes and wallet you're trying to
please. Advice from anyone is a good way to start but it's your hard
earned dollar so you should always be the final judge of a products
worth.

[UnionPac2001]

wrote:



>Beer googles for the ears?

Or maybe even beer GOGGLES. : )

[Dave Plowman]

In article >,
Powell > wrote:
> > > For example, better designs might include having isolated
> > > transformers, balanced design technology, regeneration of
> > > the wave form, outlet isolation/open ground, provide for
> > > special need of source/power amps just to prevent
> > > electrical grid injection noise.
> >
> > You must be referring to US stuff. All UK equipment
> > already has an isolating transformer. It would be illegal
> > to sell one without.
> >
> Please re-read the above paragraph. It<s >transformers"...
> that means plural in English.

> plural >adjective 1 more than one in number. 2 Grammar
> (of a word or form) denoting more than one.

So that should read "a better *design* might include having isolating
transformers"?

Pillock.

--
*Corduroy pillows are making headlines.

Dave Plowman London SW 12
RIP Acorn

[Stewart Pinkerton]

On Wed, 14 Apr 2004 17:22:56 +0100, Dave Plowman
> wrote:

>In article >,
> Powell > wrote:
>> Most audio stores will allow you to demo these devices for free so there
>> is no financial risk. The cost of these units start at $200 and run up
>> to $4,000 depending on your needs.
>
>For a few chokes and capacitors at most? Some people have more money than
>sense. Better to buy equipment where the maker has catered for possible
>mains borne interference.

Quite so. Anything with a CE mark has to adhere to pretty rigid
standards for protection against EMI susceptibility.

>> For a periodical review of these units check out Stereophile issue Vol.
>> 17 No. 12.
>
>Love to know how you arrange for a 'dirty' mains supply to be anything
>like typical.

Live in an apartment block next to a welding shop? :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Mike Gilmour]

"Stewart Pinkerton" > wrote in message
...
> On Wed, 14 Apr 2004 17:22:56 +0100, Dave Plowman
> > wrote:
>
> >In article >,
> > Powell > wrote:
> >> Most audio stores will allow you to demo these devices for free so
there
> >> is no financial risk. The cost of these units start at $200 and run up
> >> to $4,000 depending on your needs.
> >
> >For a few chokes and capacitors at most? Some people have more money than
> >sense. Better to buy equipment where the maker has catered for possible
> >mains borne interference.
>
> Quite so. Anything with a CE mark has to adhere to pretty rigid
> standards for protection against EMI susceptibility.
>
> >> For a periodical review of these units check out Stereophile issue
Vol.
> >> 17 No. 12.
> >
> >Love to know how you arrange for a 'dirty' mains supply to be anything
> >like typical.
>
> Live in an apartment block next to a welding shop? :-)
> --
>
> Stewart Pinkerton | Music is Art - Audio is Engineering

Now that would be really unfortunate!

What constitutes 'dirty' mains anyway? What about utilities signalling
systems, mains borne baby alarms, intercom systems etc, not as invasive as
Stewarts suggestion of a neighbouring welding shop but pollution never the
less. I'm way out the in country but 'scoping my mains showed evenly
spaced spikes... tracked down to an electric fence a third of a mile away.
;-)

Mike

[Dave Plowman]

In article >,
Mike Gilmour > wrote:
> What constitutes 'dirty' mains anyway? What about utilities signalling
> systems, mains borne baby alarms, intercom systems etc, not as
> invasive as Stewarts suggestion of a neighbouring welding shop but
> pollution never the less. I'm way out the in country but 'scoping my
> mains showed evenly spaced spikes... tracked down to an electric fence a
> third of a mile away. ;-)

A well designed mains transformer will attenuate anything outside about 50
Hz by a considerable amount - if it didn't, decent audio transformers
wouldn't be so expensive. ;-)

Here in London, the mains is anything but a pure sine wave - I'd guess
because of all the SWPS around.

--
*Don't worry; it only seems kinky the first time.*

Dave Plowman London SW 12
RIP Acorn

[Powell]

"Dave Plowman" wrote

> > > > For example, better designs might include having isolated
> > > > transformers, balanced design technology, regeneration of
> > > > the wave form, outlet isolation/open ground, provide for
> > > > special need of source/power amps just to prevent
> > > > electrical grid injection noise.
> > >
> > > You must be referring to US stuff. All UK equipment
> > > already has an isolating transformer. It would be illegal
> > > to sell one without.
> > >
> > Please re-read the above paragraph. It's "transformers"...
> > that means plural in English.
>
> > plural >adjective 1 more than one in number. 2 Grammar
> > (of a word or form) denoting more than one.
>
> So that should read "a better *design* might include having
> isolating transformers"?
>
I think you need a bigger shovel.

[Nick Gorham]

Dave Plowman wrote:
> In article >,
> Mike Gilmour > wrote:
>
>>What constitutes 'dirty' mains anyway? What about utilities signalling
>>systems, mains borne baby alarms, intercom systems etc, not as
>>invasive as Stewarts suggestion of a neighbouring welding shop but
>>pollution never the less. I'm way out the in country but 'scoping my
>>mains showed evenly spaced spikes... tracked down to an electric fence a
>>third of a mile away. ;-)
>
>
> A well designed mains transformer will attenuate anything outside about 50
> Hz by a considerable amount - if it didn't, decent audio transformers
> wouldn't be so expensive. ;-)

I have seen normal mains torroids used as valve output transformers.
Thay do a adiquate job, so they must let through (in that situation
anyway) > 50hz.

--
Nick

[Arny Krueger]

Nick Gorham wrote:
> Dave Plowman wrote:
>> In article >,
>> Mike Gilmour > wrote:
>>
>>> What constitutes 'dirty' mains anyway? What about utilities
>>> signalling systems, mains borne baby alarms, intercom systems etc,
>>> not as invasive as Stewarts suggestion of a neighbouring welding
>>> shop but pollution never the less. I'm way out the in country but
>>> 'scoping my mains showed evenly spaced spikes... tracked down to an
>>> electric fence a third of a mile away. ;-)
>>
>>
>> A well designed mains transformer will attenuate anything outside
>> about 50 Hz by a considerable amount - if it didn't, decent audio
>> transformers wouldn't be so expensive. ;-)
>
> I have seen normal mains torroids used as valve output transformers.
> Thay do a adiquate job, so they must let through (in that situation
> anyway) > 50hz.

The transformer is the secondary or tertiary line of defense. The power
supply itself carries the major burden.

A typical power supply for audio gear has about 15 VAC on the secondary of
the transformer, which includes a lot of power line and trash. The
rectifier actually ups the trash content by quite a bit so we're still
talking something like 15 volts of power line and other trash at the input
to the filter cap(s). Most audio gear filters the mess with a simple
capacitive filter, which brings the trash content down to a volt or two.
Then, the DC+trash goes through a commodity voltage regulator chip that
costs $0.50 or less. The trash is now under 1 millivolt. Total attenuation
gets us from 15 volts or more of trash to less than one millivolt or trash
or more than 80 dB of attenuation.

On top of the good the power supply does, most audio gear has additional
power supply rejection built into the circuitry itself. There is another 20
or more dB of trash attenuation there, so total trash attenuation is 100 dB
or more.

In every case the power line frequency is the predominate source of trash.
Most of the means used to deal with the trash are very broad band, so the
basic process of keeping power line hum away from the output terminals also
nails the other kinds of trash.

[dave weil]

On Thu, 15 Apr 2004 10:13:39 -0400, "Arny Krueger" >
wrote:

>Nick Gorham wrote:
>> Dave Plowman wrote:
>>> In article >,
>>> Mike Gilmour > wrote:
>>>
>>>> What constitutes 'dirty' mains anyway? What about utilities
>>>> signalling systems, mains borne baby alarms, intercom systems etc,
>>>> not as invasive as Stewarts suggestion of a neighbouring welding
>>>> shop but pollution never the less. I'm way out the in country but
>>>> 'scoping my mains showed evenly spaced spikes... tracked down to an
>>>> electric fence a third of a mile away. ;-)
>>>
>>>
>>> A well designed mains transformer will attenuate anything outside
>>> about 50 Hz by a considerable amount - if it didn't, decent audio
>>> transformers wouldn't be so expensive. ;-)
>>
>> I have seen normal mains torroids used as valve output transformers.
>> Thay do a adiquate job, so they must let through (in that situation
>> anyway) > 50hz.
>
>The transformer is the secondary or tertiary line of defense. The power
>supply itself carries the major burden.
>
>A typical power supply for audio gear has about 15 VAC on the secondary of
>the transformer, which includes a lot of power line and trash. The
>rectifier actually ups the trash content by quite a bit so we're still
>talking something like 15 volts of power line and other trash at the input
>to the filter cap(s). Most audio gear filters the mess with a simple
>capacitive filter, which brings the trash content down to a volt or two.
>Then, the DC+trash goes through a commodity voltage regulator chip that
>costs $0.50 or less. The trash is now under 1 millivolt. Total attenuation
>gets us from 15 volts or more of trash to less than one millivolt or trash
>or more than 80 dB of attenuation.
>
>On top of the good the power supply does, most audio gear has additional
>power supply rejection built into the circuitry itself. There is another 20
>or more dB of trash attenuation there, so total trash attenuation is 100 dB
>or more.
>
>In every case the power line frequency is the predominate source of trash.
>Most of the means used to deal with the trash are very broad band, so the
>basic process of keeping power line hum away from the output terminals also
>nails the other kinds of trash.

Nice explanation. Keep it up.

[Nick Gorham]

Arny Krueger wrote:
> Nick Gorham wrote:
>
>>Dave Plowman wrote:
>>
>>>In article >,
>>> Mike Gilmour > wrote:
>>>
>>>
>>>>What constitutes 'dirty' mains anyway? What about utilities
>>>>signalling systems, mains borne baby alarms, intercom systems etc,
>>>>not as invasive as Stewarts suggestion of a neighbouring welding
>>>>shop but pollution never the less. I'm way out the in country but
>>>>'scoping my mains showed evenly spaced spikes... tracked down to an
>>>>electric fence a third of a mile away. ;-)
>>>
>>>
>>>A well designed mains transformer will attenuate anything outside
>>>about 50 Hz by a considerable amount - if it didn't, decent audio
>>>transformers wouldn't be so expensive. ;-)
>>
>>I have seen normal mains torroids used as valve output transformers.
>>Thay do a adiquate job, so they must let through (in that situation
>>anyway) > 50hz.
>
>
> The transformer is the secondary or tertiary line of defense. The power
> supply itself carries the major burden.

Agreed, I was just pointing out that transformers on their own did
little, and as you say a cap input PSU with cheap rectifiers may well
create move crud than gets in from he mains.

Not sure however just how many power output stages are driven from a
regulated supply, I would have expected the pre stages to be fed from a
regulated supply.

--
Nick

[Arny Krueger]

Nick Gorham wrote:
> Arny Krueger wrote:
>> Nick Gorham wrote:
>>
>>> Dave Plowman wrote:
>>>
>>>> In article >,
>>>> Mike Gilmour > wrote:
>>>>
>>>>
>>>>> What constitutes 'dirty' mains anyway? What about utilities
>>>>> signalling systems, mains borne baby alarms, intercom systems
>>>>> etc, not as invasive as Stewarts suggestion of a neighbouring
>>>>> welding shop but pollution never the less. I'm way out the in
>>>>> country but 'scoping my mains showed evenly spaced spikes...
>>>>> tracked down to an electric fence a third of a mile away. ;-)
>>
>>>> A well designed mains transformer will attenuate anything outside
>>>> about 50 Hz by a considerable amount - if it didn't, decent audio
>>>> transformers wouldn't be so expensive. ;-)

>>> I have seen normal mains torroids used as valve output transformers.
>>> Thay do a adiquate job, so they must let through (in that situation
>>> anyway) > 50hz.

>> The transformer is the secondary or tertiary line of defense. The
>> power supply itself carries the major burden.

> Agreed, I was just pointing out that transformers on their own did
> little, and as you say a cap input PSU with cheap rectifiers may well
> create move crud than gets in from he mains.

It's almost a certainty! Basically the rectifiers take a sine wave with a
few percent crud or less, and turn it into something that has tens of
percent of THD when meausred.

> Not sure however just how many power output stages are driven from a
> regulated supply,

Typically there is no formal regulation in the power supply related to the
feed for the output stages..

Under full load, there are usually several volts of AC across the power
supply caps. It's easy enough to measure in most power amps.

The first line of defense is the power supply noise rejection of the power
amp itself. That that this is sufficient to build power amps with all noise
and distortion 90 or more dB down should be noted.

> I would have expected the pre stages to be fed from a regulated supply.

That is usually the case. The early stages of the main part of the power amp
circuit often run off the same source as the output devices. In other cases
there is some built-in extra filtering.

http://www.citycom.gr/electronics/projects/100Wampl/100ampl5.gif shows a
fairly typical design. Everthing runs off the same voltage source as the
output devices.

BTW, RIP Doub Self's "Amplifier Institute". A sad loss.

[tony sayer]

In article >, Arny Krueger
> writes
>Nick Gorham wrote:
>> Dave Plowman wrote:
>>> In article >,
>>> Mike Gilmour > wrote:
>>>
>>>> What constitutes 'dirty' mains anyway? What about utilities
>>>> signalling systems, mains borne baby alarms, intercom systems etc,
>>>> not as invasive as Stewarts suggestion of a neighbouring welding
>>>> shop but pollution never the less. I'm way out the in country but
>>>> 'scoping my mains showed evenly spaced spikes... tracked down to an
>>>> electric fence a third of a mile away. ;-)
>>>
>>>
>>> A well designed mains transformer will attenuate anything outside
>>> about 50 Hz by a considerable amount - if it didn't, decent audio
>>> transformers wouldn't be so expensive. ;-)
>>
>> I have seen normal mains torroids used as valve output transformers.
>> Thay do a adiquate job, so they must let through (in that situation
>> anyway) > 50hz.
>
>The transformer is the secondary or tertiary line of defense. The power
>supply itself carries the major burden.
>
>A typical power supply for audio gear has about 15 VAC on the secondary of
>the transformer, which includes a lot of power line and trash. The
>rectifier actually ups the trash content by quite a bit so we're still
>talking something like 15 volts of power line and other trash at the input
>to the filter cap(s). Most audio gear filters the mess with a simple
>capacitive filter, which brings the trash content down to a volt or two.
>Then, the DC+trash goes through a commodity voltage regulator chip that
>costs $0.50 or less. The trash is now under 1 millivolt. Total attenuation
>gets us from 15 volts or more of trash to less than one millivolt or trash
>or more than 80 dB of attenuation.
>
>On top of the good the power supply does, most audio gear has additional
>power supply rejection built into the circuitry itself. There is another 20
>or more dB of trash attenuation there, so total trash attenuation is 100 dB
>or more.
>
>In every case the power line frequency is the predominate source of trash.
>Most of the means used to deal with the trash are very broad band, so the
>basic process of keeping power line hum away from the output terminals also
>nails the other kinds of trash.
>
>

15 volts seems a tad low when I last looked the Audiolab amps had about
twice that. Not that I can say I've ever had a problem with power line
supplies....
--
Tony Sayer

[Mike Gilmour]

"Arny Krueger" > wrote in message
...
> Nick Gorham wrote:
> > Dave Plowman wrote:
> >> In article >,
> >> Mike Gilmour > wrote:
> >>
> >>> What constitutes 'dirty' mains anyway? What about utilities
> >>> signalling systems, mains borne baby alarms, intercom systems etc,
> >>> not as invasive as Stewarts suggestion of a neighbouring welding
> >>> shop but pollution never the less. I'm way out the in country but
> >>> 'scoping my mains showed evenly spaced spikes... tracked down to an
> >>> electric fence a third of a mile away. ;-)
> >>
> >>
> >> A well designed mains transformer will attenuate anything outside
> >> about 50 Hz by a considerable amount - if it didn't, decent audio
> >> transformers wouldn't be so expensive. ;-)
> >
> > I have seen normal mains torroids used as valve output transformers.
> > Thay do a adiquate job, so they must let through (in that situation
> > anyway) > 50hz.
>
> The transformer is the secondary or tertiary line of defense. The power
> supply itself carries the major burden.
>
> A typical power supply for audio gear has about 15 VAC on the secondary
of
> the transformer, which includes a lot of power line and trash. The
> rectifier actually ups the trash content by quite a bit so we're still
> talking something like 15 volts of power line and other trash at the input
> to the filter cap(s). Most audio gear filters the mess with a simple
> capacitive filter, which brings the trash content down to a volt or two.
> Then, the DC+trash goes through a commodity voltage regulator chip that
> costs $0.50 or less. The trash is now under 1 millivolt. Total
attenuation
> gets us from 15 volts or more of trash to less than one millivolt or
trash
> or more than 80 dB of attenuation.
>
> On top of the good the power supply does, most audio gear has additional
> power supply rejection built into the circuitry itself. There is another
20
> or more dB of trash attenuation there, so total trash attenuation is 100
dB
> or more.
>
> In every case the power line frequency is the predominate source of trash.
> Most of the means used to deal with the trash are very broad band, so the
> basic process of keeping power line hum away from the output terminals
also
> nails the other kinds of trash.
>
>
Replacing rectifiers with Schottky barrier ones that supposedly don't
generate reverse recovery transients from stored charge & minority carrier
injection - does that change the situation much even if you don't use a
regulator chip?

[Arny Krueger]

The Devil wrote:
> On Thu, 15 Apr 2004 12:36:58 -0400, "Arny Krueger" >
> wrote:
>
>> That is usually the case. The early stages of the main part of the
>> power amp circuit often run off the same source as the output
>> devices. In other cases there is some built-in extra filtering.
>>
>> http://www.citycom.gr/electronics/projects/100Wampl/100ampl5.gif
>> shows a fairly typical design. Everthing runs off the same voltage
>> source as the output devices.
>
> If by 'extra filtering' you're talking about C9 and 1, then it's not
> really very useful-

I'm not talking about that at all. Sorry for any possible lack of clarity. I
intended this to be an example of a power amp where everything runs off the
same basic voltage source as the output devices. In fact, that's what I
said - " Everything runs off the same voltage
source as the output devices."


>-those capacitors will follow the main smoothing
> capacitors and discharge through the output stage.

Agreed.

> A schottky diode to
> separate the main supply capacitors from local smoothing on an
> isolated small signal supply would work wonders to reject rail sags
> and grunge caused by the output stage.

As a rule, tweaks such as this just don't have any practical technical
advantages. Wire 'em in and there's usually no visible effect on the display
of residuals from distortion analyzer.

[Dave Plowman]

In article >,
Nick Gorham > wrote:
> > A well designed mains transformer will attenuate anything outside
> > about 50 Hz by a considerable amount - if it didn't, decent audio
> > transformers wouldn't be so expensive. ;-)

> I have seen normal mains torroids used as valve output transformers.
> Thay do a adiquate job, so they must let through (in that situation
> anyway) > 50hz.

I must admit to not having tested a toroidal - it's ages since I looked at
this. But if it's letting through significant amounts of 'interference'
that the normal smoothing and decoupling doesn't stop within the audio
band, I'd assume you'd hear it.

--
*The e-mail of the species is more deadly than the mail *

Dave Plowman London SW 12
RIP Acorn

[Ian Bell]

Arny Krueger wrote:


>
> BTW, RIP Doub Self's "Amplifier Institute". A sad loss.

Ouch. What happened. Any idea why it went? We have already lost Linsley
Hood, Doug Self hasn't gone too has he?

Ian

[Chris Morriss]

In message >, Dave Plowman
> writes
>In article >,
> Nick Gorham > wrote:
>> > A well designed mains transformer will attenuate anything outside
>> > about 50 Hz by a considerable amount - if it didn't, decent audio
>> > transformers wouldn't be so expensive. ;-)
>
>> I have seen normal mains torroids used as valve output transformers.
>> Thay do a adiquate job, so they must let through (in that situation
>> anyway) > 50hz.
>
>I must admit to not having tested a toroidal - it's ages since I looked at
>this. But if it's letting through significant amounts of 'interference'
>that the normal smoothing and decoupling doesn't stop within the audio
>band, I'd assume you'd hear it.
>

Don't forget that the toroids used in audio amps tend not to have
inter-winding screens. The inter-winding capacitance also tends to be
higher than that of E-I core transformers. They therefore let through
pretty much all the common-mode noise on the mains.

I know that neutral is bonded to ground at the sub-station, but in many
places the common-mode on the mains is horrible (not helped by all the
CM crap coming out of SMPSUs, even those with power-factor correction).
A good common-mode filter will clean things up a lot.


--
Chris Morriss

[Chris Morriss]

In message >, Ian Bell
> writes
>Arny Krueger wrote:
>
>
>>
>> BTW, RIP Doub Self's "Amplifier Institute". A sad loss.
>
>Ouch. What happened. Any idea why it went? We have already lost Linsley
>Hood, Doug Self hasn't gone too has he?
>
>Ian
>
Oh heavens, JLH hasn't died has he? If so, then that is a loss.
--
Chris Morriss

[Old Fart at Play]

Ian Bell wrote:

> Ouch. What happened. Any idea why it went? We have already lost Linsley
> Hood, Doug Self hasn't gone too has he?


Has Linsley-Hood died? I didn't know. Do tell.

--
Roger.

[Arny Krueger]

Old Fart at Play wrote:
> Ian Bell wrote:
>
>> Ouch. What happened. Any idea why it went? We have already lost
>> Linsley Hood, Doug Self hasn't gone too has he?


I see no evidence of that.


> Has Linsley-Hood died? I didn't know. Do tell.


I've found two references to the event. Here's the one that is the clearest:

http://www.thisisthewestcountry.co.uk/the_west_country/somerset/taunton/bdm/104.html


"LINSLEY HOOD. John of Monkton Heathfield,
passed peacefully away at Musgrove Park
Hospital on 11th March 2004, aged 79 years.
The funeral service takes place at Taunton
Deane Crematorium, today, Friday 19th March
at 12.00. No flowers by request, but
donations if desired for St Margaret's
Somerset Hospice may be sent to The Funeral
Directors Nigel K Ford, North End, Creech
St Michael, Taunton, TA3 5ED."

[James Harris]

"S888Wheel" > wrote in message
...
<snip>
> >My hi-fi sounds great sometimes and not others.
<snip>
> Maybe you could give us the specifics on your system.

Nad C541i as transport,
Meridian 203 DAC,
Rotel RA-02 amp,
Dynaudio Audience 62 floorstand speakers

Chord Optichord digital link,
Audioquest Python interconnects,
Atlas 2.0 speaker cable,
Atacama Equinox rack

The dealer advised a 30 to 60 minute warmup before each listening session - which is a
pain and I'm not convinced that the improved sound quality follows such a warmup. The
improvement seems random - and unexpected. Maybe mains problems? The sonic difference to
the bass is quite clear. Forgive the adjectives but when it's not working well the sound
is OK but 'thin' and lacks energy. When it works well the bass is rich and the sound
fuller and more musical at the same volume. It even sounds good with the volume lower.

The Audioquest Pythons were the last addition. I wasn't happy with the system - it didn't
have the clarity - until they were added to replace Atlas Voyagers. Does the kit list
above give any clues as to why the sound would change? (BTW, thanks too for your
suggestions on test CDs.)

[Arny Krueger]

The Devil wrote:
> On Thu, 15 Apr 2004 14:03:06 -0400, "Arny Krueger" >
> wrote:
>
>>>> That is usually the case. The early stages of the main part of the
>>>> power amp circuit often run off the same source as the output
>>>> devices. In other cases there is some built-in extra filtering.
>>>>
>>>> http://www.citycom.gr/electronics/projects/100Wampl/100ampl5.gif
>>>> shows a fairly typical design. Everything runs off the same voltage
>>>> source as the output devices.
>>>
>>> If by 'extra filtering' you're talking about C9 and 1, then it's not
>>> really very useful-
>>
>> I'm not talking about that at all. Sorry for any possible lack of
>> clarity. I intended this to be an example of a power amp where
>> everything runs off the same basic voltage source as the output
>> devices.
>
> No, I don't understand.

What's unclear about the explanation I just gave you?

>You said 'In other cases there is some
> built-in extra filtering,' and you provided a link to an amp that has
> local smoothing provided by capacitors 8 and 1. Now you say you
> weren't 'talking about that at all'.

There is he slight matter of the sentence:

"Everything runs off the same voltage source as the output devices."

Same paragraph as the link.


>> As a rule, tweaks such as this just don't have any practical
>> technical advantages.

> And of course we all know that pretty much every nominally competent
> amp (in terms of measurement) sounds just like any other of same . . .

You know that, eh? I perceive a change of philosophy on your part. When did
this happen?

[S888Wheel]

>From: "James Harris" no.email.please
>Date: 4/15/2004 1:31 PM Pacific Standard Time
>Message-id: >
>
>"S888Wheel" > wrote in message
...
><snip>
>> >My hi-fi sounds great sometimes and not others.
><snip>
>> Maybe you could give us the specifics on your system.
>
>Nad C541i as transport,
>Meridian 203 DAC,
>Rotel RA-02 amp,
>Dynaudio Audience 62 floorstand speakers
>
>Chord Optichord digital link,
>Audioquest Python interconnects,
>Atlas 2.0 speaker cable,
>Atacama Equinox rack
>
>The dealer advised a 30 to 60 minute warmup before each listening session -
>which is a
>pain and I'm not convinced that the improved sound quality follows such a
>warmup.

Well it doesn't sound like a true warm up issue.

The
>improvement seems random - and unexpected. Maybe mains problems? The sonic
>difference to
>the bass is quite clear. Forgive the adjectives but when it's not working
>well the sound
>is OK but 'thin' and lacks energy. When it works well the bass is rich and
>the sound
>fuller and more musical at the same volume. It even sounds good with the
>volume lower.

I don't see how any kind of warm up could ever make that kind of difference
with your equipment.


>
>The Audioquest Pythons were the last addition. I wasn't happy with the system
>- it didn't
>have the clarity - until they were added to replace Atlas Voyagers. Does the
>kit list
>above give any clues as to why the sound would change?


No. Not at all. I'd say there may be something malfunctioning.


(BTW, thanks too for
>your
>suggestions on test CDs.)

Quite welcome.
>
>
>
>
>
>
>
>
>

[Tat Chan]

James Harris wrote:
> "S888Wheel" > wrote in message
> ...
> <snip>
>
>>>My hi-fi sounds great sometimes and not others.
>
> <snip>
>
>>Maybe you could give us the specifics on your system.
>
>
> Nad C541i as transport,
> Meridian 203 DAC,
> Rotel RA-02 amp,
> Dynaudio Audience 62 floorstand speakers
>


James, I am curious. The Meridian DAC is at least 12 years old. I would
have thought that the newer Burr Brown DACs in the NAD would measure
better and produce "better" sound than the older Philips DAC in the
Meridian (is it multibit or bitstream?)

[Stewart Pinkerton]

On Thu, 15 Apr 2004 22:58:23 +0100, The Devil > wrote:

>On Thu, 15 Apr 2004 17:36:25 -0400, "Arny Krueger" >
>wrote:

>>> And of course we all know that pretty much every nominally competent
>>> amp (in terms of measurement) sounds just like any other of same . . .
>>
>>You know that, eh? I perceive a change of philosophy on your part. When did
>>this happen?
>
>It didn't. I know it's bull****.

Oh, really? I'm still up for it if you are, with your trusty
Quads...........

--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Jim Lesurf]

In article >, James Harris
<no.email.please> wrote:
> "S888Wheel" > wrote in message
> ... <snip>
> > >My hi-fi sounds great sometimes and not others.
> <snip>
> > Maybe you could give us the specifics on your system.

> Nad C541i as transport, Meridian 203 DAC, Rotel RA-02 amp, Dynaudio
> Audience 62 floorstand speakers

> Chord Optichord digital link, Audioquest Python interconnects, Atlas 2.0
> speaker cable, Atacama Equinox rack

Since this is being cross-posted to 'opinion'... :-)

FWIW I use two main systems. One now uses a pair of ESL63's and a Meridian
263 DAC. The other now uses a pair of ESL988's and a Meridian 563 DAC. (You
may spot a pattern, here... ;-> )

In each case I tend to switch the speaker energisation and DAC power on in
the morning, and off at the end of the evening. I have a slight impression
that the speakers (and maybe the DACs) benefit from this. However the
changes are so small I am not at all sure of this. I general I don't bother
switching on amplifiers more than a few mins before use. So far as I can
tell, letting my amplifiers warm up has no effect that seems audible to me.


> The dealer advised a 30 to 60 minute warmup before each listening
> session - which is a pain and I'm not convinced that the improved sound
> quality follows such a warmup. The improvement seems random - and
> unexpected. Maybe mains problems? The sonic difference to the bass is
> quite clear. Forgive the adjectives but when it's not working well the
> sound is OK but 'thin' and lacks energy. When it works well the bass is
> rich and the sound fuller and more musical at the same volume. It even
> sounds good with the volume lower.

> The Audioquest Pythons were the last addition. I wasn't happy with the
> system - it didn't have the clarity - until they were added to replace
> Atlas Voyagers. Does the kit list above give any clues as to why the
> sound would change? (BTW, thanks too for your suggestions on test CDs.)

I also hear (apparent) changes from time to time in terms of relative bass
level, etc. However it does not seem to correlate with anything so I
suspect it is just my perceptions altering as a result of various
'extraneous' influences...

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[Jim Lesurf]

In article >,
Tat Chan > wrote:
> James Harris wrote:

> > Nad C541i as transport,
> > Meridian 203 DAC,
> > Rotel RA-02 amp,
> > Dynaudio Audience 62 floorstand speakers
> >


> James, I am curious. The Meridian DAC is at least 12 years old. I would
> have thought that the newer Burr Brown DACs in the NAD would measure
> better and produce "better" sound than the older Philips DAC in the
> Meridian (is it multibit or bitstream?)

I doubt that this is simply a matter of choice of DAC chip. Other
influences will include the PSU, buffering, differences in filtering, etc.

FWIW I remain a fan of the Meridian 263 and 563, (as well as the Quad 67)
despite them being 'out of favour' for a while for technical reasons.

Maybe they'll become popular again if SACD really takes hold. A situation
with a certain wry irony for Bob Stuart if it occurs... ;->

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[Jim Lesurf]

In article >, Mike Gilmour
> wrote:

> >
> >
> Replacing rectifiers with Schottky barrier ones that supposedly don't
> generate reverse recovery transients from stored charge & minority
> carrier injection - does that change the situation much even if you
> don't use a regulator chip?

When designing/building amps myself I just used to shove small caps in
parallel with each bridge diode to eat the 'snap'...

However for me the main line of defence was a design that inherently had a
good amount of rail ripple/noise/interference rejection, and good earthing.
This means that even of HF rubbish gets through the PSU them amp will
largely ignore it.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[Arny Krueger]

Tat Chan wrote:

> James, I am curious. The Meridian DAC is at least 12 years old. I
> would have thought that the newer Burr Brown DACs in the NAD would
> measure better and produce "better" sound than the older Philips DAC
> in the Meridian (is it multibit or bitstream?)

As old as the 203 is, there's a good chance that a $39.95 Apex DVD player
has better-performing DACs. Seriously.

[Tat Chan]

Jim Lesurf wrote:
> In article >,
> Tat Chan > wrote:
>
>>James Harris wrote:
>
>
>>>Nad C541i as transport,
>>>Meridian 203 DAC,
>>>Rotel RA-02 amp,
>>>Dynaudio Audience 62 floorstand speakers
>>>
>
>
>
>>James, I am curious. The Meridian DAC is at least 12 years old. I would
>>have thought that the newer Burr Brown DACs in the NAD would measure
>>better and produce "better" sound than the older Philips DAC in the
>>Meridian (is it multibit or bitstream?)
>
>
> I doubt that this is simply a matter of choice of DAC chip. Other
> influences will include the PSU, buffering, differences in filtering, etc.
>

well yes, but the NAD 541i is a one box solution and as such, shouldn't it have
much lower jitter levels compared to using a separate DAC and transport, even
with the well-engineered Meridian DAC?

And since the NAD player has HDCD playback capability, it must use a certain
digital filter that is highly regarded? (can't remember the name of it atm)

> FWIW I remain a fan of the Meridian 263 and 563, (as well as the Quad 67)
> despite them being 'out of favour' for a while for technical reasons.
>

what would the technical reasons be? Did they process/filter the digital data in
a "funny" way?


> Maybe they'll become popular again if SACD really takes hold. A situation
> with a certain wry irony for Bob Stuart if it occurs... ;->
>

and why would that be? (possibly related to my question above)

[Tat Chan]

Arny Krueger wrote:

> Tat Chan wrote:
>
>
>>James, I am curious. The Meridian DAC is at least 12 years old. I
>>would have thought that the newer Burr Brown DACs in the NAD would
>>measure better and produce "better" sound than the older Philips DAC
>>in the Meridian (is it multibit or bitstream?)
>
>
> As old as the 203 is, there's a good chance that a $39.95 Apex DVD player
> has better-performing DACs. Seriously.
>
>

OK, the DAC in the newer elcheapo DVD player might be better performing, but I
doubt the analogue output stage would be better than the Meridian's (granted, I
am moving the goalposts here, since I have now changed the point from DAC to
output stage)

[Arny Krueger]

Tat Chan wrote:
> Arny Krueger wrote:

>> Tat Chan wrote:

>>> James, I am curious. The Meridian DAC is at least 12 years old. I
>>> would have thought that the newer Burr Brown DACs in the NAD would
>>> measure better and produce "better" sound than the older Philips DAC
>>> in the Meridian (is it multibit or bitstream?)

>> As old as the 203 is, there's a good chance that a $39.95 Apex DVD
>> player has better-performing DACs. Seriously.

> OK, the DAC in the newer elcheapo DVD player might be better
> performing, but I doubt the analogue output stage would be better
> than the Meridian's (granted, I am moving the goalposts here, since I
> have now changed the point from DAC to output stage)

I wouldn't be too sure of that. For one thing, even solid state audio gear
doesn't last forever.

[unitron]

"Woody" > wrote in message >...

---snip---
>
> Your hearing is done by a 'field' of very fine hairs inside your ear canal
> that flex with the air movement that we call sound.

---snip---

An otherwise excellent post, but just to avoid unintentionally
misleading anyone, those hairs flex indirectly with the air movement
(localized variations in pressure) which we call sound. Those hairs
are in a fluid-filled chamber to which the vibrations of your eardrum
caused by sound are coupled through some little bitty bones. The air
doesn't move those hairs directly, and as far as I know they have
absolutely nothing to do with those "other ear hairs" that show up and
start growing like crabgrass somewhere in middle age.

[unitron]

"Fleetie" > wrote in message >...
> "Mike Gilmour" > wrote
> > My hi-fi sounds great late night and during the early hours... single malt
> > may have a lot to do with it ;-)
>
> Beer googles for the ears?
>
>
> Martin

My ears google for free beer :-)

[Stewart Pinkerton]

On 16 Apr 2004 12:15:06 -0700, (unitron) wrote:

>"Fleetie" > wrote in message >...
>> "Mike Gilmour" > wrote
>> > My hi-fi sounds great late night and during the early hours... single malt
>> > may have a lot to do with it ;-)
>>
>> Beer googles for the ears?
>>
>>
>> Martin
>
> My ears google for free beer :-)

Perhaps he meant beerphones? :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

[Jim Lesurf]

In article >, Tat Chan
> wrote:
> Jim Lesurf wrote:

> >
> > I doubt that this is simply a matter of choice of DAC chip. Other
> > influences will include the PSU, buffering, differences in filtering,
> > etc.
> >

> well yes, but the NAD 541i is a one box solution and as such, shouldn't
> it have much lower jitter levels compared to using a separate DAC and
> transport, even with the well-engineered Meridian DAC?

It will certainly help that the SPDIF transfer is avoided in a one-box
system. However the Meridian systems seem to have very good reclocking,
etc. In then end it would come down to how well each systems was actually
engineered.

In my case I use each DAC for multiple sources, so some sort of transfer is
involved. However if I was buying a new Cd player today it would probably
be a meridian one-box system. :-)

> And since the NAD player has HDCD playback capability, it must use a
> certain digital filter that is highly regarded? (can't remember the
> name of it atm)

> > FWIW I remain a fan of the Meridian 263 and 563, (as well as the Quad
> > 67) despite them being 'out of favour' for a while for technical
> > reasons.
> >

> what would the technical reasons be? Did they process/filter the digital
> data in a "funny" way?

They use low-bit sigma-delta. Hence they tend to produce the same sort of
ultrasonic 'hash' as SACD. Can also, theoretically, suffer from some of the
same drawbacks as other low-bit methods. However in the end this comes down
to how good a job the engineers did.

> > Maybe they'll become popular again if SACD really takes hold. A
> > situation with a certain wry irony for Bob Stuart if it occurs... ;->
> >

> and why would that be? (possibly related to my question above)

Because Bob is what might be termed a 'critic' of the SACD system and he
would prefer LPCM as used in DVD-A to avoid the potential problems of SACD.
Yet he made a neat job of sigma-delta DACs of a similar type before moving
on to what he would now - I think - say were 'better'.

From his POV SACD is probably a 'step backwards' to a method he discarded
about 10 years ago. But at the time he made nice DACs that way...

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[Mark Hennessy]

"Arny Krueger" > wrote in message
...

> BTW, RIP Doub Self's "Amplifier Institute". A sad loss.

http://www.dself.dsl.pipex.com/ampins/ampins.htm

Cheers,

Mark

[Chris Isbell]

On Fri, 16 Apr 2004 11:43:39 +0100, Jim Lesurf
> wrote:

>In each case I tend to switch the speaker energisation and DAC power on in
>the morning, and off at the end of the evening. I have a slight impression
>that the speakers (and maybe the DACs) benefit from this.

The manual for the Quad '57 speakers recommends leaving them powered
all the time and not switching them off. Is the advice given for the
'63/988/989 different?

My Stax electrostatic headphones sound noticeably 'edgy' for the first
few minutes after switch-on. I have not investigated this in any
detail, but it seems reasonable that high-impedance capacitive systems
will need a little time to stabilise because there may be some fairly
long time constants associated with the biasing supply.

This would tie in with the instructions Quad provide for monitoring
the HT bias supplies of the '57 in which they specify the use of an
electrostatic volt meter because the input impedance of a standard
meter is sufficiently low to affect the reading. (Of course in those
days, the majority of meters were not electronic.)


--
Chris Isbell
Southampton
UK

[Jim Lesurf]

In article >, Chris Isbell
> wrote:
> On Fri, 16 Apr 2004 11:43:39 +0100, Jim Lesurf >
> wrote:

> >In each case I tend to switch the speaker energisation and DAC power on
> >in the morning, and off at the end of the evening. I have a slight
> >impression that the speakers (and maybe the DACs) benefit from this.

> The manual for the Quad '57 speakers recommends leaving them powered all
> the time and not switching them off. Is the advice given for the
> '63/988/989 different?

I don't have the 63 booklet to hand. My recollection is that it also
recommends leaving the mains 'on' all the time.

Looking at the blue one for the 988's I can't find a mention of this,
though.

Ideally, I'd leave them powered all the time. However I tend to be wary of
leaving items on overnight due to the very slight risk of fire.

> My Stax electrostatic headphones sound noticeably 'edgy' for the first
> few minutes after switch-on. I have not investigated this in any detail,
> but it seems reasonable that high-impedance capacitive systems will need
> a little time to stabilise because there may be some fairly long time
> constants associated with the biasing supply.

My impression is that the speakers do improve over a few hours of being
'on'. However this may be my ears, of course, not the speakers. :-)

On one occasion I was away for a week and left the 63's unpowered. I cam
home and started listening to music. It was only after about ten minutes
that I realised that I'd set the volume about 6dB higher than usual, and
that the sound was 'not quite right'. I hadn't turned on the energisation.
:-)

This shows that they do sometimes keep a surprisingly high charge for a
long time.

IIRC the 57's would not hold charge like this, though.

I'm not sure, but suspect the problem may be that the charge distribution
(rather than amount) needs to 'settle' and this takes times as the
diaphragm is actually quite resistive. Also any moisture may need to be
'ionised away' by leakage. This might be a reason for allowing the speakers
to be powered for a long time.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[tony sayer]

In article >, Chris Isbell
> writes
>On Fri, 16 Apr 2004 11:43:39 +0100, Jim Lesurf
> wrote:
>
>>In each case I tend to switch the speaker energisation and DAC power on in
>>the morning, and off at the end of the evening. I have a slight impression
>>that the speakers (and maybe the DACs) benefit from this.
>
>The manual for the Quad '57 speakers recommends leaving them powered
>all the time and not switching them off. Is the advice given for the
>'63/988/989 different?

Leave mine on all the time, doesn't seem to harm them. Better than not
remembering to switch them on as other members of the tribe here use
them and would forget!....

--
Tony Sayer

[Dave Plowman]

In article >,
Jim Lesurf > wrote:
> I'm not sure, but suspect the problem may be that the charge
> distribution (rather than amount) needs to 'settle' and this takes times
> as the diaphragm is actually quite resistive. Also any moisture may need
> to be 'ionised away' by leakage. This might be a reason for allowing the
> speakers to be powered for a long time.

I'd agree with the moisture thing - it's the same with condenser mics. But
because one particular type of speaker benefits from being left on (or
warmed up), it doesn't mean other things necessarily will.

--
*He's not dead - he's electroencephalographically challenged

Dave Plowman London SW 12
RIP Acorn

[Chris Isbell]

On Sun, 18 Apr 2004 12:22:19 +0100, Jim Lesurf
> wrote:

>On one occasion I was away for a week and left the 63's unpowered. I cam
>home and started listening to music. It was only after about ten minutes
>that I realised that I'd set the volume about 6dB higher than usual, and
>that the sound was 'not quite right'. I hadn't turned on the energisation.
>:-)
>
>This shows that they do sometimes keep a surprisingly high charge for a
>long time.
>
>IIRC the 57's would not hold charge like this, though.
>

My experience is that they hold up for about ten minutes. (This is
based on the occasion when my better half unplugged one of them to do
some ironing. The reeducation programme appears to have been effective
and she has not repeated the offence. ;-)


--
Chris Isbell
Southampton
UK

[Tat Chan]

Jim Lesurf wrote:

<snip>

thanks for all the info.

>
>>what would the technical reasons be? Did they process/filter the digital
>>data in a "funny" way?
>
>
> They use low-bit sigma-delta. Hence they tend to produce the same sort of
> ultrasonic 'hash' as SACD. Can also, theoretically, suffer from some of the
> same drawbacks as other low-bit methods. However in the end this comes down
> to how good a job the engineers did.
>
>

would the ultrasonic hash lead to a "pleasing" kind of distortion? On a
thread a few weeks back, it was pointed out the my Rotel 965BX CD player
was noisy, with a lot of ultrasonic noise. And, the Rotel was one of the
early bitstream CD players as well (I am under the impression that SACD
uses a conversion method similar to bitstream conversion from the early 90s)

And could the ultrasonic noise explain why some people have been
comparing SACD to vinyl?

>>>Maybe they'll become popular again if SACD really takes hold. A
>>>situation with a certain wry irony for Bob Stuart if it occurs... ;->
>>>
>
>>and why would that be? (possibly related to my question above)
>
>
> Because Bob is what might be termed a 'critic' of the SACD system and he
> would prefer LPCM as used in DVD-A to avoid the potential problems of SACD.

and he's responsible for the MLP (Meridian Lossless Packing) format used
in DVD-A!

[Jim Lesurf]

In article >, Tat Chan
> wrote:
> Jim Lesurf wrote:

> <snip>

> thanks for all the info.

> >
> >>what would the technical reasons be? Did they process/filter the
> >>digital data in a "funny" way?
> >
> >
> > They use low-bit sigma-delta. Hence they tend to produce the same sort
> > of ultrasonic 'hash' as SACD. Can also, theoretically, suffer from
> > some of the same drawbacks as other low-bit methods. However in the
> > end this comes down to how good a job the engineers did.
> >
> >

> would the ultrasonic hash lead to a "pleasing" kind of distortion?

Short answer: "Pass" :-)

Longer answer: "I suppose it might do in some circumstances. Indeed, I
wrote an article that Hi Fi News published a few months ago that included
this speculation as a possibility springing from the nonlinear nature of
human hearing." :-)

> On a thread a few weeks back, it was pointed out the my Rotel 965BX CD
> player was noisy, with a lot of ultrasonic noise. And, the Rotel was one
> of the early bitstream CD players as well (I am under the impression
> that SACD uses a conversion method similar to bitstream conversion from
> the early 90s)

> And could the ultrasonic noise explain why some people have been
> comparing SACD to vinyl?

Again, I refer you to my above-mentioned article. :-)

Since I am in "plug" mode... There will be a follow-on article in a few
months. Book your issue of HFN early to avoid dissapointment. ;->

FWIW once the next item appears in the magazine, I am hoping to put a
longer account of the background, etc, on one of my websites.

> >
> > Because Bob is what might be termed a 'critic' of the SACD system and
> > he would prefer LPCM as used in DVD-A to avoid the potential problems
> > of SACD.

> and he's responsible for the MLP (Meridian Lossless Packing) format used
> in DVD-A!

Yes. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scots_Guide/intro/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

[James Harris]

"Tat Chan" > wrote in message
...
<snip>
> >
> > Nad C541i as transport,
> > Meridian 203 DAC,
> > Rotel RA-02 amp,
> > Dynaudio Audience 62 floorstand speakers
> >
>
>
> James, I am curious. The Meridian DAC is at least 12 years old. I would
> have thought that the newer Burr Brown DACs in the NAD would measure
> better and produce "better" sound than the older Philips DAC in the
> Meridian (is it multibit or bitstream?)

Well, since you asked I tried going back to the direct link from the CD player to the amp.
I soon went back to the DAC. The reason? I wouldn't like to say the DAC is "better" but is
a sound I prefer.

The DAC gives greater bass weight and authority and also opens out the voices. They sound
more clear and distinct with the DAC than with the Nad CD player alone.

I would still like more reach in the bass, though. That may be to do with my speakers more
than the electronics.

--
Cheers,
James

[Tat Chan]

Jim Lesurf wrote:

> In article >, Tat Chan
> > wrote:
>

>>would the ultrasonic hash lead to a "pleasing" kind of distortion?
>
>
> Short answer: "Pass" :-)
>
> Longer answer: "I suppose it might do in some circumstances. Indeed, I
> wrote an article that Hi Fi News published a few months ago that included
> this speculation as a possibility springing from the nonlinear nature of
> human hearing." :-)
>

UK magazines take a few months to reach Oz. With any luck, the newsagent will
have that copy in stock.

>
> Since I am in "plug" mode... There will be a follow-on article in a few
> months. Book your issue of HFN early to avoid dissapointment. ;->
>
> FWIW once the next item appears in the magazine, I am hoping to put a
> longer account of the background, etc, on one of my websites.
>

looking forward to it.

[Tat Chan]

James Harris wrote:

> "Tat Chan" > wrote in message
> ...
> <snip>
>
>>
>>James, I am curious. The Meridian DAC is at least 12 years old. I would
>>have thought that the newer Burr Brown DACs in the NAD would measure
>>better and produce "better" sound than the older Philips DAC in the
>>Meridian (is it multibit or bitstream?)
>
>
> Well, since you asked I tried going back to the direct link from the CD player to the amp.
> I soon went back to the DAC. The reason? I wouldn't like to say the DAC is "better" but is
> a sound I prefer.
>
> The DAC gives greater bass weight and authority and also opens out the voices. They sound
> more clear and distinct with the DAC than with the Nad CD player alone.
>

Interesting. I was thinking of getting a 203 DAC, as the shop I bought my
speakers from have one for sale, but the £160 they are charging seems a bit steep.

> I would still like more reach in the bass, though. That may be to do with my speakers more
> than the electronics.
>
well, your floorstanders will produce more bass than my bookshelves!

[James Harris]

"Tat Chan" > wrote in message news:c636ei$79kno$1@ID-
<snip>
>
> Interesting. I was thinking of getting a 203 DAC, as the shop I bought my
> speakers from have one for sale, but the £160 they are charging seems a bit steep.

I paid £150 (IIRC) for the unit second hand but I did get a chance to try it out for a
couple of weeks before parting with my cash. Your local shop may let you try the unit for
a few days before deciding.

[James Harris]

"James Harris" <no.email.please> wrote in message
.. .
> "S888Wheel" > wrote in message
> ...
> <snip>
> > >My hi-fi sounds great sometimes and not others.
> <snip>
> > Maybe you could give us the specifics on your system.
>
> Nad C541i as transport,
> Meridian 203 DAC,
> Rotel RA-02 amp,
> Dynaudio Audience 62 floorstand speakers
>
> Chord Optichord digital link,
> Audioquest Python interconnects,
> Atlas 2.0 speaker cable,
> Atacama Equinox rack
>
> The dealer advised a 30 to 60 minute warmup before each listening session - which is a
> pain and I'm not convinced that the improved sound quality follows such a warmup. The
> improvement seems random - and unexpected. Maybe mains problems? The sonic difference to
> the bass is quite clear. Forgive the adjectives but when it's not working well the sound
> is OK but 'thin' and lacks energy. When it works well the bass is rich and the sound
> fuller and more musical at the same volume. It even sounds good with the volume lower.
>
> The Audioquest Pythons were the last addition. I wasn't happy with the system - it
didn't
> have the clarity - until they were added to replace Atlas Voyagers. Does the kit list
> above give any clues as to why the sound would change? (BTW, thanks too for your
> suggestions on test CDs.)

A followup on this. I have since been kindly lent a Quad 405 power amp. With this the
system does NOT need a warm up. As before the kit is left on all the time.

--
James

[James Harris]

"James Harris" <no.email.please> wrote in message
.. .
>
> "Tat Chan" > wrote in message
> ...
> <snip>
> > >
> > > Nad C541i as transport,
> > > Meridian 203 DAC,
> > > Rotel RA-02 amp,
> > > Dynaudio Audience 62 floorstand speakers
> > >
> >
> >
> > James, I am curious. The Meridian DAC is at least 12 years old. I would
> > have thought that the newer Burr Brown DACs in the NAD would measure
> > better and produce "better" sound than the older Philips DAC in the
> > Meridian (is it multibit or bitstream?)
>
> Well, since you asked I tried going back to the direct link from the CD player to the
amp.
> I soon went back to the DAC. The reason? I wouldn't like to say the DAC is "better" but
is
> a sound I prefer.
>
> The DAC gives greater bass weight and authority and also opens out the voices. They
sound
> more clear and distinct with the DAC than with the Nad CD player alone.
>
> I would still like more reach in the bass, though. That may be to do with my speakers
more
> than the electronics.

Have since added a borrowed Quad 405 power amp. While this has removed the warm-up time
needed before I still would like greater reach in the bass - and probably a little less of
it! I think then that this must be to do with my Dynaudio speakers. The cones in them are
probably too small to reach as far down as I would like. Oh well. The neighbours can
breathe a sigh of relief....

--
James

[Fleetie]

"James Harris" <no.email.please> wrote
> Have since added a borrowed Quad 405 power amp. While this has removed the warm-up time
> needed before I still would like greater reach in the bass - and probably a little less of
> it! I think then that this must be to do with my Dynaudio speakers. The cones in them are
> probably too small to reach as far down as I would like. Oh well. The neighbours can
> breathe a sigh of relief....

If you have Dynaudios, stop damn complaining! :-) Which ones?

*Envy*


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.fleetie.demon.co.uk

[Frédéric Mathieu]

James, any comment about the Atacama Equinox rack? Is it the Av, HiFi, or XL
Pro? I am about to buy one of these, are you happy with it?

--



"James Harris" <no.email.please> a écrit dans le message de
...
>
> "James Harris" <no.email.please> wrote in message
> .. .
> > "S888Wheel" > wrote in message
> > ...
> > <snip>
> > > >My hi-fi sounds great sometimes and not others.
> > <snip>
> > > Maybe you could give us the specifics on your system.
> >
> > Nad C541i as transport,
> > Meridian 203 DAC,
> > Rotel RA-02 amp,
> > Dynaudio Audience 62 floorstand speakers
> >
> > Chord Optichord digital link,
> > Audioquest Python interconnects,
> > Atlas 2.0 speaker cable,
> > Atacama Equinox rack
> >
> > The dealer advised a 30 to 60 minute warmup before each listening
session - which is a
> > pain and I'm not convinced that the improved sound quality follows such
a warmup. The
> > improvement seems random - and unexpected. Maybe mains problems? The
sonic difference to
> > the bass is quite clear. Forgive the adjectives but when it's not
working well the sound
> > is OK but 'thin' and lacks energy. When it works well the bass is rich
and the sound
> > fuller and more musical at the same volume. It even sounds good with the
volume lower.
> >
> > The Audioquest Pythons were the last addition. I wasn't happy with the
system - it
> didn't
> > have the clarity - until they were added to replace Atlas Voyagers. Does
the kit list
> > above give any clues as to why the sound would change? (BTW, thanks too
for your
> > suggestions on test CDs.)
>
> A followup on this. I have since been kindly lent a Quad 405 power amp.
With this the
> system does NOT need a warm up. As before the kit is left on all the time.
>
> --
> James
>
>

[James Harris]

"Fleetie" > wrote in message
news:_DLpc.359$nB5.344@newsfe1-win...
> "James Harris" <no.email.please> wrote
> > Have since added a borrowed Quad 405 power amp. While this has removed the warm-up
time
> > needed before I still would like greater reach in the bass - and probably a little
less of
> > it! I think then that this must be to do with my Dynaudio speakers. The cones in them
are
> > probably too small to reach as far down as I would like. Oh well. The neighbours can
> > breathe a sigh of relief....
>
> If you have Dynaudios, stop damn complaining! :-) Which ones?
>
> *Envy*

Hi Martin. Good to hear a strong positive about the Dynaudios. Since you asked, Audience
62s. Floorstanders. I went for these after also hearing the standmounted 42s (IIRC).
Amazingly for such a small box the 42s' bass was 'big' enough. There was just a different
quality of the bass from the floorstanders - as if the cones were moving in a more open
space which, in fact, they were:-) There was a more graceful quality - a more effortless
sound in the bass from the larger enclosure. I didn't plan to spend so much on speakers
but it wasn't too much more than Audience 42s plus good quality stands.

I did audition the comparable Mission floorstanders at the same time but - to my
surprise - didn't like the sound. The Missions were not cheaper versions. In fact they
were a bit more expensive - and, IIRC, were SE variants. Sorry I can't be sure about the
model number.

--
James

[James Harris]

"Frédéric Mathieu" > wrote in message
...
> James, any comment about the Atacama Equinox rack? Is it the Av, HiFi, or XL
> Pro? I am about to buy one of these, are you happy with it?

I bought the Equinox audio rack. I guess it would be the HiFi one you mention. I can't
really comment on this compared with other racks as I didn't try any others. I do find the
rack to be solid with my base unit plus two extra shelves - four in total. The triangular
design (of the pillars and feet) is convenient. Watch out, though, for its depth. It
sticks out further in to my room than I would like. There is certainly plenty of room for
deep units!

Compared with the old wooden rack and stacked components I had before placing the amp in
space on its own shelf even improved the sound from the tuner. No, really! The sound just
seemed to open out and breathe more freely. I still find this hard to believe. One day
I'll go back to stacked units just to convince myself.......

--
HTH,
James

[[email protected]]

"James Harris" <no.email.please> wrote in message
...
>
> Have since added a borrowed Quad 405 power amp. While this has removed the
warm-up time
> needed before I still would like greater reach in the bass - and probably
a little less of
> it! I think then that this must be to do with my Dynaudio speakers. The
cones in them are
> probably too small to reach as far down as I would like. Oh well. The
neighbours can
> breathe a sigh of relief....
>

If you want decent bass a 405 will not give it to you.

This ancient amplifier is both bandwidth and current limited and has a
rather nasty protection circuit in it.

The 405-2 was a bit better and the various modified 405's a lot better.

In standard form it is probably unable to drive your Dynaudios properly.


cheers,

[Bruce J. Richman]

James Harris wrote:


>"Frédéric Mathieu" > wrote in message
...
>> James, any comment about the Atacama Equinox rack? Is it the Av, HiFi, or
>XL
>> Pro? I am about to buy one of these, are you happy with it?
>
>I bought the Equinox audio rack. I guess it would be the HiFi one you
>mention. I can't
>really comment on this compared with other racks as I didn't try any others.
>I do find the
>rack to be solid with my base unit plus two extra shelves - four in total.
>The triangular
>design (of the pillars and feet) is convenient. Watch out, though, for its
>depth. It
>sticks out further in to my room than I would like. There is certainly plenty
>of room for
>deep units!
>
>Compared with the old wooden rack and stacked components I had before placing
>the amp in
>space on its own shelf even improved the sound from the tuner. No, really!
>The sound just
>seemed to open out and breathe more freely. I still find this hard to
>believe. One day
>I'll go back to stacked units just to convince myself.......
>
>--
>HTH,
>James
>
>
>
>
>
>
>
>
>

OSAO!! :) (No need to prove it).

Always nice to see audio related threads.


Bruce J. Richman