Question about passive preamps

[Schizoid Man]

After doing the rounds, I'm leaning towards the McCormack TLC-1.

This preamp has got a passive out. However, according to a Stereophile
article I read, this unit still needs to be powered up to use the
passive out.

My question is: why?

Or am I just overdue for EE 101? :-)

[Robert Morein]

"Schizoid Man" > wrote in message
...
> After doing the rounds, I'm leaning towards the McCormack TLC-1.
>
> This preamp has got a passive out. However, according to a Stereophile
> article I read, this unit still needs to be powered up to use the passive
> out.
>
> My question is: why?
Probably just a relay that has to be powered to switch into bypass mode.
>
> Or am I just overdue for EE 101? :-)
Don't let bullies kick sand in your face :)

[Schizoid Man]

Robert Morein wrote:
> "Schizoid Man" > wrote in message
> ...
>
>>After doing the rounds, I'm leaning towards the McCormack TLC-1.
>>
>>This preamp has got a passive out. However, according to a Stereophile
>>article I read, this unit still needs to be powered up to use the passive
>>out.
>>
>>My question is: why?
>
> Probably just a relay that has to be powered to switch into bypass mode.
>
>>Or am I just overdue for EE 101? :-)
>
> Don't let bullies kick sand in your face :)

Any experience with this unit? I am undecided between this and a Rotel
RC-995.

In all likelihood, I will not use the McCormack in passive mode, so in a
direct comparison it is about $100 more expensive than the Rotel. Plus,
the Rotel has a remote.

[George M. Middius]

Schizoid Man said:

> In all likelihood, I will not use the McCormack in passive mode, so in a
> direct comparison it is about $100 more expensive than the Rotel. Plus,
> the Rotel has a remote.

The only way a pre without a remote would be conceivable is if you're sure
it'll always be within easy reach. Unless you like sprinting to mute the
system when the phone rings.

[Trevor Wilson]

"George M. Middius" <cmndr [underscore] george [at] comcast [dot] net> wrote
in message ...
>
>
> Schizoid Man said:
>
>> In all likelihood, I will not use the McCormack in passive mode, so in a
>> direct comparison it is about $100 more expensive than the Rotel. Plus,
>> the Rotel has a remote.
>
> The only way a pre without a remote would be conceivable is if you're sure
> it'll always be within easy reach. Unless you like sprinting to mute the
> system when the phone rings.

**You just gotta learn to kick that Pavlovian impulse. If I'm doing
something (anything) and the 'phone rings, I'll ignore it.


--
Trevor Wilson
www.rageaudio.com.au

[Robert Morein]

"Schizoid Man" > wrote in message
...
> Robert Morein wrote:
>> "Schizoid Man" > wrote in message
>> ...
>>
>>>After doing the rounds, I'm leaning towards the McCormack TLC-1.
>>>
>>>This preamp has got a passive out. However, according to a Stereophile
>>>article I read, this unit still needs to be powered up to use the passive
>>>out.
>>>
>>>My question is: why?
>>
>> Probably just a relay that has to be powered to switch into bypass mode.
>>
>>>Or am I just overdue for EE 101? :-)
>>
>> Don't let bullies kick sand in your face :)
>
> Any experience with this unit? I am undecided between this and a Rotel
> RC-995.
>
> In all likelihood, I will not use the McCormack in passive mode, so in a
> direct comparison it is about $100 more expensive than the Rotel. Plus,
> the Rotel has a remote.

I would prefer a unit with discrete output devices. Does either unit specify
this?
The advantages of a passive remote are in the range of barely positive to
very negative, depending upon whether the output stage of the player is a
good one.
A good preamp can be a tremendous asset, by allowing the player outputs to
"coast".

[Trevor Wilson]

"Schizoid Man" > wrote in message
...
> After doing the rounds, I'm leaning towards the McCormack TLC-1.
>
> This preamp has got a passive out. However, according to a Stereophile
> article I read, this unit still needs to be powered up to use the passive
> out.
>
> My question is: why?

**It is possible that other stuff within the 'preamp' requires power. Remote
controls, muting circuits, etc. Personally, I reckon that a GOOD active
preamp will win any contest with a passive preamp hands down. Passive
preamps have a number of disadvantages, which are obviated by decent active
preamps:

* High output impedance. Not only will the output impedance be high, but, in
most cases, will vary according to the volume control position.
* Zero gain. This may or may not be an issue, depending on the system.
Flexibility is limited with passives, however.


--
Trevor Wilson
www.rageaudio.com.au

[Bret Ludwig]

Robert Morein wrote:

> >
> > Any experience with this unit? I am undecided between this and a Rotel
> > RC-995.
> >
> > In all likelihood, I will not use the McCormack in passive mode, so in a
> > direct comparison it is about $100 more expensive than the Rotel. Plus,
> > the Rotel has a remote.
>
> I would prefer a unit with discrete output devices. Does either unit specify
> this?
> The advantages of a passive remote are in the range of barely positive to
> very negative, depending upon whether the output stage of the player is a
> good one.
> A good preamp can be a tremendous asset, by allowing the player outputs to
> "coast".

Gain is gain. There are obvious and clear advantages to putting it in
the player, instead of in a second box with one more set of
interconnects and another power supply. Since power amplifiers work at
the same input voltage levels as most electronic units-CD players,
DACs, tape machines, tuners, etc-put out (else the "passive preamp"
would be not just a misnomer but an impossibility) the three box
solution makes no sense anymore now that turntables are not only not
the primary, but increasingly nonexistent sources.

A good universal player with a good rugged drive mechanism, a low
impedance well designed output section (which I will concede might be
just as well solid state, as per Hamm et al, the undisputed authority
on such matters until Arny publishes otherwise in JAES or other peer
reviewed publication), a volume control and perhaps even a remote
control well constructed, driving the power amplifier directly is the
obvious best solution.

[paul packer]

On Sat, 10 Dec 2005 22:50:58 -0500, "Robert Morein"
> wrote:

>
>"Schizoid Man" > wrote in message
...
>> After doing the rounds, I'm leaning towards the McCormack TLC-1.
>>
>> This preamp has got a passive out. However, according to a Stereophile
>> article I read, this unit still needs to be powered up to use the passive
>> out.
>>
>> My question is: why?
>Probably just a relay that has to be powered to switch into bypass mode.

This reminds me, why do I have to have my Marantz PM8200 switched on
in order to record to minidisc through the tape out? With every
previous amp I could record with the amp switched off.

[George M. Middius]

Trevor Wilson said:

> > The only way a pre without a remote would be conceivable is if you're sure
> > it'll always be within easy reach. Unless you like sprinting to mute the
> > system when the phone rings.

> **You just gotta learn to kick that Pavlovian impulse. If I'm doing
> something (anything) and the 'phone rings, I'll ignore it.

Must do wonders for your social life.

[Bret Ludwig]

Trevor Wilson wrote:
> "Schizoid Man" > wrote in message
> ...
> > After doing the rounds, I'm leaning towards the McCormack TLC-1.
> >
> > This preamp has got a passive out. However, according to a Stereophile
> > article I read, this unit still needs to be powered up to use the passive
> > out.
> >
> > My question is: why?
>
> **It is possible that other stuff within the 'preamp' requires power. Remote
> controls, muting circuits, etc. Personally, I reckon that a GOOD active
> preamp will win any contest with a passive preamp hands down. Passive
> preamps have a number of disadvantages, which are obviated by decent active
> preamps:
>
> * High output impedance. Not only will the output impedance be high, but, in
> most cases, will vary according to the volume control position.
> * Zero gain. This may or may not be an issue, depending on the system.
> Flexibility is limited with passives, however.

Proper perception of the issue is being impeded by verbiage here.

A "passive preamp" is no such thing at all. It is a
selector/attenuator, acting as a signal switching box and a variable
signal attenuator.

Preamps made perfect sense in the days when the phono cartridge was
the primary first signal source in most any hi-fi system. Even then,
tape recorders and tuners produced plenty enough signal to drive any
power amplifier. The preamp was a "preamp" with the primary source as
well as a signal selector and level control with all sources.

Whatever the merits and demerits of vinyl, and of analog tape even
more so, they are not the primary source for audiophiles today, in most
instances. Optical disk players, outboard DACs and tuners are the only
sources in more systems than not and tuners are getting scarcer as the
quality of broadcast sources gets poorer and poorer except in a few
markets like New York.

Therefore, the optical disk player or outboard DAC should be expected
to have an output of low impedance and high enough in level to drive
any power amp: indeed, it's no more a design burden if one specifies
it must be able to fit into the +4, 600 ohm pro world, especially if
true balanced operation is not specified, because most pro gear today
is not true-balanced. If this is not the case, is the passive
pseudo-preamp at fault or the source unit?

Naysayers will squawk that that's not the way it is. It is obviously
the way it ought to be.

Consider also that putting the volume control on the source unit
rather than the amplifier has a number of merits. It obviates the need
for unit-to-unit level matching and makes switching between a
background and foreground source much easier.

By putting a volume control and multiple inputs on a power amplifier,
it becomes a "line-stage integrated" amplifier. This in today's
perverted market makes it less pricey rather than more, so we have a
marketing issue right up fromt. (McIntosh, to their credit, put volume
controls on many of their power amps: however, there is no switching
and the volume control is a common ganged pot.)

"George M. Middius" <cmndr [underscore] george [at] comcast [dot] net> wrote
in message ...
>
>
> Schizoid Man said:
>
>> In all likelihood, I will not use the McCormack in passive mode, so in a
>> direct comparison it is about $100 more expensive than the Rotel. Plus,
>> the Rotel has a remote.
>
> The only way a pre without a remote would be conceivable is if you're sure
> it'll always be within easy reach. Unless you like sprinting to mute the
> system when the phone rings.>

You know, that's an interesting point. What the world needs is a device
that can output a remote code when the phone rings. It would be inserted in
the phone line at either end of the phone cord, and programmed to output the
code for PAUSE and MUTE when the phone rings. When you hang up, it repeats
the process to return you to where you were. Since it's a learning remote,
it can output any 2 codes, making it useful for people who have other things
they want it to do. Come to think of it, such a device could be designed to
output a complete macro.

The real problem with such a device is that fewer and fewer people use land
line phones. It wouldn't work with a cell phone unless it was in a cradle.

Norm Strong

[Robert Morein]

"Bret Ludwig" > wrote in message
oups.com...
>
> Robert Morein wrote:
>
>> >
>> > Any experience with this unit? I am undecided between this and a Rotel
>> > RC-995.
>> >
>> > In all likelihood, I will not use the McCormack in passive mode, so in
>> > a
>> > direct comparison it is about $100 more expensive than the Rotel. Plus,
>> > the Rotel has a remote.
>>
>> I would prefer a unit with discrete output devices. Does either unit
>> specify
>> this?
>> The advantages of a passive remote are in the range of barely positive to
>> very negative, depending upon whether the output stage of the player is a
>> good one.
>> A good preamp can be a tremendous asset, by allowing the player outputs
>> to
>> "coast".
>
> Gain is gain. There are obvious and clear advantages to putting it in
> the player, instead of in a second box with one more set of
> interconnects and another power supply.

Sure, and if the CD player has a good output stage, I agree. BUT, a passive
preamp does have a notable disadvantage: high and variable output impedance.
The leads to the amplifier should be very short, because a passive pre is an
extremely poor line driver.

[Robert Morein]

"paul packer" > wrote in message
...
> On Sat, 10 Dec 2005 22:50:58 -0500, "Robert Morein"
> > wrote:
>
>>
>>"Schizoid Man" > wrote in message
...
>>> After doing the rounds, I'm leaning towards the McCormack TLC-1.
>>>
>>> This preamp has got a passive out. However, according to a Stereophile
>>> article I read, this unit still needs to be powered up to use the
>>> passive
>>> out.
>>>
>>> My question is: why?
>>Probably just a relay that has to be powered to switch into bypass mode.
>
> This reminds me, why do I have to have my Marantz PM8200 switched on
> in order to record to minidisc through the tape out? With every
> previous amp I could record with the amp switched off.

Perhaps it has an active buffer amp for the tape out. This is considered
desirable, because it isolates the circuitry from "rectification effects"
that backfeed intoa preamp without a passive buffer, when the recorder is
turned off, UNLESS the recorder has FET inputs, in which case this does not
happen.

Sorry about the German ;)

[Powell]

"Bret Ludwig" wrote

> Proper perception of the issue is being impeded
> by verbiage here.
>
Yes, but your perception may be in error.


> A "passive preamp" is no such thing at all. It is a
> selector/attenuator, acting as a signal switching
> box and a variable signal attenuator.
>
True, and as a result most outboard devices like
CD players, tuners, etc. lack enough RMS
voltage to adequately drive power amps. Most
mainstream preamps will output 5-50 volts.


> Preamps made perfect sense in the days when
> the phono cartridge was the primary first signal
> source in most any hi-fi system. Even then, tape
> recorders and tuners produced plenty enough
> signal to drive any power amplifier.
>
Really, please site common makes and models
that did this (recorders and tuners).


> Naysayers will squawk that that's not the way
> it is. It is obviously the way it ought to be.
>
I think you misunderstand the primary reason
variable outputs are supplied, in addition to fixed
outputs, on input devices (players, tuners,ext.)


> Consider also that putting the volume control on
> the source unit rather than the amplifier has a
> number of merits. It obviates the need for
> unit-to-unit level matching and makes switching
> between a background and foreground source
> much easier.
>
No, that is the primary reason variable outputs are
supplied at all on players. Most often when you
choose to go with the variable output you
are compromising fidelity for convenience.

[Trevor Wilson]

"George M. Middius" <cmndr [underscore] george [at] comcast [dot] net> wrote
in message ...
>
>
> Trevor Wilson said:
>
>> > The only way a pre without a remote would be conceivable is if you're
>> > sure
>> > it'll always be within easy reach. Unless you like sprinting to mute
>> > the
>> > system when the phone rings.
>
>> **You just gotta learn to kick that Pavlovian impulse. If I'm doing
>> something (anything) and the 'phone rings, I'll ignore it.
>
> Must do wonders for your social life.

**What social life? -:)


--
Trevor Wilson
www.rageaudio.com.au

[Robert Morein]

"Powell" > wrote in message
...
>
> "Bret Ludwig" wrote
>
>> Proper perception of the issue is being impeded
>> by verbiage here.
>>
> Yes, but your perception may be in error.
>
>
>> A "passive preamp" is no such thing at all. It is a
>> selector/attenuator, acting as a signal switching
>> box and a variable signal attenuator.
>>
> True, and as a result most outboard devices like
> CD players, tuners, etc. lack enough RMS
> voltage to adequately drive power amps. Most
> mainstream preamps will output 5-50 volts.
>
This is true, and they do it more cleanly than all but the most competently
engineered players.
It is a mistake to think a passive pre will result in a cleaner signal path.

[Bret Ludwig]

Powell wrote:

> > A "passive preamp" is no such thing at all. It is a
> > selector/attenuator, acting as a signal switching
> > box and a variable signal attenuator.
> >
> True, and as a result most outboard devices like
> CD players, tuners, etc. lack enough RMS
> voltage to adequately drive power amps. Most
> mainstream preamps will output 5-50 volts.

Most power amps will go full output with 1.5V rms. VTL in their book
specify they design for input sensitivity of 775 mV as I recall.

>
>
> > Preamps made perfect sense in the days when
> > the phono cartridge was the primary first signal
> > source in most any hi-fi system. Even then, tape
> > recorders and tuners produced plenty enough
> > signal to drive any power amplifier.
> >
> Really, please site common makes and models
> that did this (recorders and tuners).

The Ampex AG440 is the only tape recorder I have much experience with.
It would _drive the snot_ out of our solid state McIntosh amps.
>
>
> > Naysayers will squawk that that's not the way
> > it is. It is obviously the way it ought to be.
> >
> I think you misunderstand the primary reason
> variable outputs are supplied, in addition to fixed
> outputs, on input devices (players, tuners,ext.)
>
>
> > Consider also that putting the volume control on
> > the source unit rather than the amplifier has a
> > number of merits. It obviates the need for
> > unit-to-unit level matching and makes switching
> > between a background and foreground source
> > much easier.
> >
> No, that is the primary reason variable outputs are
> supplied at all on players. Most often when you
> choose to go with the variable output you
> are compromising fidelity for convenience.

Because mainstream consumo players have Mickey Mouse variable outputs!

This is becoming a tautology. I am advocating a practice that is not
currently universal, not describing what people now do that doesn't
work as well.

[Robert Morein]

"Bret Ludwig" > wrote in message
oups.com...
>
> Powell wrote:
>
>> > A "passive preamp" is no such thing at all. It is a
>> > selector/attenuator, acting as a signal switching
>> > box and a variable signal attenuator.
>> >
>> True, and as a result most outboard devices like
>> CD players, tuners, etc. lack enough RMS
>> voltage to adequately drive power amps. Most
>> mainstream preamps will output 5-50 volts.
>
> Most power amps will go full output with 1.5V rms. VTL in their book
> specify they design for input sensitivity of 775 mV as I recall.
>

Yes, but from practical experience with Sony ES players, I can tell you that
those with 5532 outputs cannot do it cleanly.

[Bret Ludwig]

Robert Morein wrote:
<<snip>>
> > Most power amps will go full output with 1.5V rms. VTL in their book
> > specify they design for input sensitivity of 775 mV as I recall.
> >
>
> Yes, but from practical experience with Sony ES players, I can tell you that
> those with 5532 outputs cannot do it cleanly.

i don't dispute this, but, what is the rail voltage on these devices?

[Robert Morein]

"Bret Ludwig" > wrote in message
oups.com...
>
> Robert Morein wrote:
> <<snip>>
>> > Most power amps will go full output with 1.5V rms. VTL in their book
>> > specify they design for input sensitivity of 775 mV as I recall.
>> >
>>
>> Yes, but from practical experience with Sony ES players, I can tell you
>> that
>> those with 5532 outputs cannot do it cleanly.
>
> i don't dispute this, but, what is the rail voltage on these devices?
>
I think it's around 12.
Look, here's my personal approach to good sound:
1. I don't do mods. I'm just not into it, even though I have all the
equipment at hands. My priorities are elsewhere.
2. Good preamps, being simpler than practically any other part, are not hard
to find. A nice discrete Class A gain stage can be found in a Hafler DH-110
for next to nothing. I use these, or the Hafler 915, to buffer several
systems. It sounds great.
3. If the player, or cheap preamp, is operating in the negative gain region,
the opamps behave themselves, as mediocre as they may be.
4. I use a lot of hardware that does not pass a high-ender muster. For
example the Sony TA-E1000ESD, a remarkable surround processor circa 1991,
actually has excellent DACs. But the outputs are weak. So my lazy man's
solution is to buffer the cheap piece with a good preamp.

In my opinion, preamps are more likely than any other component, to pass the
"straight wire with gain" test, perhaps because it's so practical to test a
preamp in this manner. Many, especially the older ones with discrete stages,
do so, unless they have to drive a length of cable. Then afew extra tests
are required. The Adcom GFP-750 was a notable failure in this regard.

In one experiment, I hooked a GFP-750 and a DH-110 via a switchbox to a Stax
Lambda Pros. I really could not tell any difference. When I put twelve feet
of cable on, there was a world of difference, in favor of the Hafler.

[ScottW]

Robert Morein wrote:
> "Bret Ludwig" > wrote in message
> oups.com...
> >
> > Powell wrote:
> >
> >> > A "passive preamp" is no such thing at all. It is a
> >> > selector/attenuator, acting as a signal switching
> >> > box and a variable signal attenuator.
> >> >
> >> True, and as a result most outboard devices like
> >> CD players, tuners, etc. lack enough RMS
> >> voltage to adequately drive power amps. Most
> >> mainstream preamps will output 5-50 volts.
> >
> > Most power amps will go full output with 1.5V rms. VTL in their book
> > specify they design for input sensitivity of 775 mV as I recall.
> >
>
> Yes, but from practical experience with Sony ES players, I can tell you that
> those with 5532 outputs cannot do it cleanly.

Explain to us how putting a gain stage in front of your amp is going
to change the voltage output of your source which typically has no
level control?

Somebody stick a fork in Morein... that senile old coot is done.

ScottW

[Robert Morein]

"ScottW" > wrote in message
oups.com...
>
> Robert Morein wrote:
>> "Bret Ludwig" > wrote in message
>> oups.com...
>> >
>> > Powell wrote:
>> >
>> >> > A "passive preamp" is no such thing at all. It is a
>> >> > selector/attenuator, acting as a signal switching
>> >> > box and a variable signal attenuator.
>> >> >
>> >> True, and as a result most outboard devices like
>> >> CD players, tuners, etc. lack enough RMS
>> >> voltage to adequately drive power amps. Most
>> >> mainstream preamps will output 5-50 volts.
>> >
>> > Most power amps will go full output with 1.5V rms. VTL in their book
>> > specify they design for input sensitivity of 775 mV as I recall.
>> >
>>
>> Yes, but from practical experience with Sony ES players, I can tell you
>> that
>> those with 5532 outputs cannot do it cleanly.
>
> Explain to us how putting a gain stage in front of your amp is going
> to change the voltage output of your source which typically has no
> level control?
>
All my players have level controls.

[Robert Morein]

"Powell" > wrote in message
...
>
[snip]>
> You underestimate the workload that is
> put upon a preamp. Just dropping a pot on
> an output voltage isn't going to make it.
> For myself, I find it easier to discern fidelity
> differences when comparing preamps,
> unlike power amps. I think that there are
> many power amp owners who underutilize
> the true capability/accuracy of power amps
> with weakling preamps.
>
Regrettably, we agree.
Your mental illness is burning out, Powell.

[Accessory Section 8]

wrote:
> "George M. Middius" <cmndr [underscore] george [at] comcast [dot] net> wrote
> in message ...
> >
> >
> > Schizoid Man said:
> >
> >> In all likelihood, I will not use the McCormack in passive mode, so in a
> >> direct comparison it is about $100 more expensive than the Rotel. Plus,
> >> the Rotel has a remote.
> >
> > The only way a pre without a remote would be conceivable is if you're sure
> > it'll always be within easy reach. Unless you like sprinting to mute the
> > system when the phone rings.>
>
> You know, that's an interesting point. What the world needs is a device
> that can output a remote code when the phone rings. It would be inserted in
> the phone line at either end of the phone cord, and programmed to output the
> code for PAUSE and MUTE when the phone rings. When you hang up, it repeats
> the process to return you to where you were. Since it's a learning remote,
> it can output any 2 codes, making it useful for people who have other things
> they want it to do. Come to think of it, such a device could be designed to
> output a complete macro.

Zenith had such a system on their color TVs in the early 1980s.

[Kalman Rubinson]

wrote:

>> You know, that's an interesting point. What the world needs is a device
>> that can output a remote code when the phone rings. It would be inserted in
>> the phone line at either end of the phone cord, and programmed to output the
>> code for PAUSE and MUTE when the phone rings. When you hang up, it repeats
>> the process to return you to where you were. Since it's a learning remote,
>> it can output any 2 codes, making it useful for people who have other things
>> they want it to do. Come to think of it, such a device could be designed to
>> output a complete macro.

Answering machine solves the interruption problem for me. ;-)

Kal

[Powell]

"Bret Ludwig" wrote

> > > A "passive preamp" is no such thing at all. It is a
> > > selector/attenuator, acting as a signal switching
> > > box and a variable signal attenuator.
> > >
> > True, and as a result most outboard devices like
> > CD players, tuners, etc. lack enough RMS
> > voltage to adequately drive power amps. Most
> > mainstream preamps will output 5-50 volts.
>
> Most power amps will go full output with
> 1.5V rms.
>
If so, give make and models you are referring to.
Most amps choke at those *line level* RMS
voltages.

After reviewing an index of preamp specifications,
of 60 or so manufacturers, the lowest RMS output
I can find is 3 Vrms for a McCormack's
MAP-1/RLD-1.

> VTL in their book specify they design for input
> sensitivity of 775 mV as I recall.
>
Power amps are not designed around one
("sensitivity") parameter.

Are you suggesting VTL preamps are
poorly matched to their power amplifer
line? All VTL preamps output (max) at
30 Vrms. Output impedance decreased
as VTL preamp model quality increases
($$$) from 200 Ohms (TL 2.5/$2K) to
20 Ohms (TL 7.5/$13.5K).


> > > Preamps made perfect sense in the days when
> > > the phono cartridge was the primary first signal
> > > source in most any hi-fi system. Even then, tape
> > > recorders and tuners produced plenty enough
> > > signal to drive any power amplifier.
> > >
> > Really, please site common makes and models
> > that did this (recorders and tuners).
>
> The Ampex AG440 is the only tape recorder
> I have much experience with. It would _drive
> the snot_ out of our solid state McIntosh amps.
> >
What model year, I'll attempt to look up
specifications in my references (Ampex
AG440/Mac).


> > > Consider also that putting the volume control on
> > > the source unit rather than the amplifier has a
> > > number of merits. It obviates the need for
> > > unit-to-unit level matching and makes switching
> > > between a background and foreground source
> > > much easier.
> > >
> > No, that is the primary reason variable outputs are
> > supplied at all on players. Most often when you
> > choose to go with the variable output you
> > are compromising fidelity for convenience.
>
> Because mainstream consumo players have
> Mickey Mouse variable outputs!
>
What's better than having choices?


> This is becoming a tautology. I am advocating a
> practice that is not currently universal, not
> describing what people now do that doesn't
> work as well.
>
Manufacturers have already designed products
that meet your needs like:
ARC CD3/$5.5K - 5.4 Vrms
Ayre C-5xe/$3K - 4.5 Vrms
Mark Levinson No 390S/$6.7K - 4.5 Vrms

You underestimate the workload that is
put upon a preamp. Just dropping a pot on
an output voltage isn't going to make it.
For myself, I find it easier to discern fidelity
differences when comparing preamps,
unlike power amps. I think that there are
many power amp owners who underutilize
the true capability/accuracy of power amps
with weakling preamps.

[ScottW]

Robert Morein wrote:
> "ScottW" > wrote in message
> oups.com...
> >
> > Robert Morein wrote:
> >> "Bret Ludwig" > wrote in message
> >> oups.com...
> >> >
> >> > Powell wrote:
> >> >
> >> >> > A "passive preamp" is no such thing at all. It is a
> >> >> > selector/attenuator, acting as a signal switching
> >> >> > box and a variable signal attenuator.
> >> >> >
> >> >> True, and as a result most outboard devices like
> >> >> CD players, tuners, etc. lack enough RMS
> >> >> voltage to adequately drive power amps. Most
> >> >> mainstream preamps will output 5-50 volts.
> >> >
> >> > Most power amps will go full output with 1.5V rms. VTL in their book
> >> > specify they design for input sensitivity of 775 mV as I recall.
> >> >
> >>
> >> Yes, but from practical experience with Sony ES players, I can tell you
> >> that
> >> those with 5532 outputs cannot do it cleanly.
> >
> > Explain to us how putting a gain stage in front of your amp is going
> > to change the voltage output of your source which typically has no
> > level control?
> >
> All my players have level controls.

Perhaps you should try one without a level control to find something
capable of putting out 0 db without distorting. I've got 3 CD
players w/o level control and none have the problem you describe.

ScottW

[Robert Morein]

"ScottW" > wrote in message
oups.com...
>
> Robert Morein wrote:
>> "ScottW" > wrote in message
>> oups.com...
>> >
>> > Robert Morein wrote:
>> >> "Bret Ludwig" > wrote in message
>> >> oups.com...
>> >> >
>> >> > Powell wrote:
>> >> >
>> >> >> > A "passive preamp" is no such thing at all. It is a
>> >> >> > selector/attenuator, acting as a signal switching
>> >> >> > box and a variable signal attenuator.
>> >> >> >
>> >> >> True, and as a result most outboard devices like
>> >> >> CD players, tuners, etc. lack enough RMS
>> >> >> voltage to adequately drive power amps. Most
>> >> >> mainstream preamps will output 5-50 volts.
>> >> >
>> >> > Most power amps will go full output with 1.5V rms. VTL in their book
>> >> > specify they design for input sensitivity of 775 mV as I recall.
>> >> >
>> >>
>> >> Yes, but from practical experience with Sony ES players, I can tell
>> >> you
>> >> that
>> >> those with 5532 outputs cannot do it cleanly.
>> >
>> > Explain to us how putting a gain stage in front of your amp is going
>> > to change the voltage output of your source which typically has no
>> > level control?
>> >
>> All my players have level controls.
>
> Perhaps you should try one without a level control to find something
> capable of putting out 0 db without distorting. I've got 3 CD
> players w/o level control and none have the problem you describe.
>
> ScottW
>
No need, the problem is solved with a preamp.

[Trevor Wilson]

"Kalman Rubinson" > wrote in message
...
>
wrote:
>
>>> You know, that's an interesting point. What the world needs is a device
>>> that can output a remote code when the phone rings. It would be
>>> inserted in
>>> the phone line at either end of the phone cord, and programmed to output
>>> the
>>> code for PAUSE and MUTE when the phone rings. When you hang up, it
>>> repeats
>>> the process to return you to where you were. Since it's a learning
>>> remote,
>>> it can output any 2 codes, making it useful for people who have other
>>> things
>>> they want it to do. Come to think of it, such a device could be
>>> designed to
>>> output a complete macro.
>
> Answering machine solves the interruption problem for me. ;-)

**Exactly! Perhaps George could adopt such a device, until he manages to
control his Pavlovian impulses.


--
Trevor Wilson
www.rageaudio.com.au

[ScottW]

Robert Morein wrote:
> "ScottW" > wrote in message
> oups.com...
> >
> > Robert Morein wrote:
> >> "ScottW" > wrote in message
> >> oups.com...
> >> >
> >> > Robert Morein wrote:
> >> >> "Bret Ludwig" > wrote in message
> >> >> oups.com...
> >> >> >
> >> >> > Powell wrote:
> >> >> >
> >> >> >> > A "passive preamp" is no such thing at all. It is a
> >> >> >> > selector/attenuator, acting as a signal switching
> >> >> >> > box and a variable signal attenuator.
> >> >> >> >
> >> >> >> True, and as a result most outboard devices like
> >> >> >> CD players, tuners, etc. lack enough RMS
> >> >> >> voltage to adequately drive power amps. Most
> >> >> >> mainstream preamps will output 5-50 volts.
> >> >> >
> >> >> > Most power amps will go full output with 1.5V rms. VTL in their book
> >> >> > specify they design for input sensitivity of 775 mV as I recall.
> >> >> >
> >> >>
> >> >> Yes, but from practical experience with Sony ES players, I can tell
> >> >> you
> >> >> that
> >> >> those with 5532 outputs cannot do it cleanly.
> >> >
> >> > Explain to us how putting a gain stage in front of your amp is going
> >> > to change the voltage output of your source which typically has no
> >> > level control?
> >> >
> >> All my players have level controls.
> >
> > Perhaps you should try one without a level control to find something
> > capable of putting out 0 db without distorting. I've got 3 CD
> > players w/o level control and none have the problem you describe.
> >
> > ScottW
> >
> No need, the problem is solved with a preamp.

Solved or masked? Obviously system S/N is degraded with such a
solution.

ScottW

[George M. Middius]

Trevor Wilson said:

> > Answering machine solves the interruption problem for me. ;-)

> **Exactly! Perhaps George could adopt such a device, until he manages to
> control his Pavlovian impulses.

In my life, the telephone is still a primary means of communication. You
might get by with email and IM, but that's not true of all of us.

[ScottW]

George M. Middius wrote:
> Trevor Wilson said:
>
> > > Answering machine solves the interruption problem for me. ;-)
>
> > **Exactly! Perhaps George could adopt such a device, until he manages to
> > control his Pavlovian impulses.
>
> In my life, the telephone is still a primary means of communication.

Translation: The phone is the only way George can pay people to
talk to him.

Live and in person is just too stressful for him in his current
condition.

No one has ever really seen George, you know. He's the phantom of
usenet.
Cue the organ please......... not that organ Marge.

ScottW

[Robert Morein]

"ScottW" > wrote in message
oups.com...
>
> Robert Morein wrote:
>> "ScottW" > wrote in message
>> oups.com...
>> >
>> > Robert Morein wrote:
>> >> "ScottW" > wrote in message
>> >> oups.com...
>> >> >
>> >> > Robert Morein wrote:
>> >> >> "Bret Ludwig" > wrote in message
>> >> >> oups.com...
>> >> >> >
>> >> >> > Powell wrote:
>> >> >> >
>> >> >> >> > A "passive preamp" is no such thing at all. It is a
>> >> >> >> > selector/attenuator, acting as a signal switching
>> >> >> >> > box and a variable signal attenuator.
>> >> >> >> >
>> >> >> >> True, and as a result most outboard devices like
>> >> >> >> CD players, tuners, etc. lack enough RMS
>> >> >> >> voltage to adequately drive power amps. Most
>> >> >> >> mainstream preamps will output 5-50 volts.
>> >> >> >
>> >> >> > Most power amps will go full output with 1.5V rms. VTL in their
>> >> >> > book
>> >> >> > specify they design for input sensitivity of 775 mV as I recall.
>> >> >> >
>> >> >>
>> >> >> Yes, but from practical experience with Sony ES players, I can tell
>> >> >> you
>> >> >> that
>> >> >> those with 5532 outputs cannot do it cleanly.
>> >> >
>> >> > Explain to us how putting a gain stage in front of your amp is going
>> >> > to change the voltage output of your source which typically has no
>> >> > level control?
>> >> >
>> >> All my players have level controls.
>> >
>> > Perhaps you should try one without a level control to find something
>> > capable of putting out 0 db without distorting. I've got 3 CD
>> > players w/o level control and none have the problem you describe.
>> >
>> > ScottW
>> >
>> No need, the problem is solved with a preamp.
>
> Solved or masked? Obviously system S/N is degraded with such a
> solution.
>
> ScottW
>
No, it is not.

[ScottW]

Robert Morein wrote:
> "ScottW" > wrote in message
> oups.com...
> >
> > Robert Morein wrote:
> >> "ScottW" > wrote in message
> >> oups.com...
> >> >
> >> > Robert Morein wrote:
> >> >> "ScottW" > wrote in message
> >> >> oups.com...
> >> >> >
> >> >> > Robert Morein wrote:
> >> >> >> "Bret Ludwig" > wrote in message
> >> >> >> oups.com...
> >> >> >> >
> >> >> >> > Powell wrote:
> >> >> >> >
> >> >> >> >> > A "passive preamp" is no such thing at all. It is a
> >> >> >> >> > selector/attenuator, acting as a signal switching
> >> >> >> >> > box and a variable signal attenuator.
> >> >> >> >> >
> >> >> >> >> True, and as a result most outboard devices like
> >> >> >> >> CD players, tuners, etc. lack enough RMS
> >> >> >> >> voltage to adequately drive power amps. Most
> >> >> >> >> mainstream preamps will output 5-50 volts.
> >> >> >> >
> >> >> >> > Most power amps will go full output with 1.5V rms. VTL in their
> >> >> >> > book
> >> >> >> > specify they design for input sensitivity of 775 mV as I recall.
> >> >> >> >
> >> >> >>
> >> >> >> Yes, but from practical experience with Sony ES players, I can tell
> >> >> >> you
> >> >> >> that
> >> >> >> those with 5532 outputs cannot do it cleanly.
> >> >> >
> >> >> > Explain to us how putting a gain stage in front of your amp is going
> >> >> > to change the voltage output of your source which typically has no
> >> >> > level control?
> >> >> >
> >> >> All my players have level controls.
> >> >
> >> > Perhaps you should try one without a level control to find something
> >> > capable of putting out 0 db without distorting. I've got 3 CD
> >> > players w/o level control and none have the problem you describe.
> >> >
> >> > ScottW
> >> >
> >> No need, the problem is solved with a preamp.
> >
> > Solved or masked? Obviously system S/N is degraded with such a
> > solution.
> >
> > ScottW
> >
> No, it is not.

If you must compensate a limited signal level source with more gain in
your preamp then you are obviously also amplifying the noise of your
source more than should be necessary and diminishing overall system
signal/noise ratio.
A better solution is a source which is capable of rated output
without distortion/clipping or whatever problem your POS adjustable
output level CD players have.

What field was that PhD reject you attained in?

ScottW

[Powell]

"ScottW" wrote

> If you must compensate a limited signal
> level source with more gain in your preamp
> then you are obviously also amplifying the
> noise of your source more than should be
> necessary and diminishing overall system
> signal/noise ratio.
>
Well, yes and no.

The volume pot is primarily used on players like
CD/DVD, phonograph head amps, tuners, etc.,
to slightly increase or reduce RMS voltage of
the player's line level outputs. For the most
part the consumer electronics industry sets
*fixed outputs/line level* at 1-2 volts.

There are plenty of alternative hybrids that
output much higher by providing preamp output
levels (5-50 Vrms). A few adequate products
were sited. Because there is so little demand
for these hybrids consumers pay a premium
price.

You would unnecessarily burden manufactures
and consumer pocketbooks with unnecessary
expenses for including additional head amp
sections in players. There is no market for this.


> A better solution is a source which is capable
> of rated output without distortion/clipping or
> whatever problem your POS adjustable
> output level CD players have.
>
I wasn't aware there were problems with players
not outputing at line level (1-2 Vrms). There
is no practical use for playing devices outputing
at any higher levels. When they do that's when
a pot is often included on the device.


> What field was that PhD reject you attained in?
>
Robert, School of Hard Knocks. What make you
so special?

[ScottW]

Powell wrote:
> "ScottW" wrote
>
> > If you must compensate a limited signal
> > level source with more gain in your preamp
> > then you are obviously also amplifying the
> > noise of your source more than should be
> > necessary and diminishing overall system
> > signal/noise ratio.
> >
> Well, yes and no.
>
> The volume pot is primarily used on players like
> CD/DVD, phonograph head amps, tuners, etc.,
> to slightly increase or reduce RMS voltage of
> the player's line level outputs. For the most
> part the consumer electronics industry sets
> *fixed outputs/line level* at 1-2 volts.
>
> There are plenty of alternative hybrids that
> output much higher by providing preamp output
> levels (5-50 Vrms). A few adequate products
> were sited. Because there is so little demand
> for these hybrids consumers pay a premium
> price.
>
> You would unnecessarily burden manufactures
> and consumer pocketbooks with unnecessary
> expenses for including additional head amp
> sections in players. There is no market for this.
>
>
> > A better solution is a source which is capable
> > of rated output without distortion/clipping or
> > whatever problem your POS adjustable
> > output level CD players have.
> >
> I wasn't aware there were problems with players
> not outputing at line level (1-2 Vrms). There
> is no practical use for playing devices outputing
> at any higher levels. When they do that's when
> a pot is often included on the device.


Moron claims his Sony player doesn't even have the balls for line
level output.

reference his response to Bret's comment:

> Most power amps will go full output with 1.5V rms. VTL in their book
> specify they design for input sensitivity of 775 mV as I recall.

Morons response:
Yes, but from practical experience with Sony ES players, I can tell you
that
those with 5532 outputs cannot do it cleanly.

So I have a couple issues with Bob's premise.
1) His crappy CD can't even provide std line level output cleanly.
2) Attenuating said output with a pot isn't likely to do anything to
clean it up.
3) Adding extra gain later to compensate will also amplify the noise
floor of the player reducing overall system S/N.

ScottW

[Robert Morein]

"ScottW" > wrote in message
ups.com...
>
> Powell wrote:
>> "ScottW" wrote
>>
>> > If you must compensate a limited signal
>> > level source with more gain in your preamp
>> > then you are obviously also amplifying the
>> > noise of your source more than should be
>> > necessary and diminishing overall system
>> > signal/noise ratio.
>> >
>> Well, yes and no.
>>
>> The volume pot is primarily used on players like
>> CD/DVD, phonograph head amps, tuners, etc.,
>> to slightly increase or reduce RMS voltage of
>> the player's line level outputs. For the most
>> part the consumer electronics industry sets
>> *fixed outputs/line level* at 1-2 volts.
>>
>> There are plenty of alternative hybrids that
>> output much higher by providing preamp output
>> levels (5-50 Vrms). A few adequate products
>> were sited. Because there is so little demand
>> for these hybrids consumers pay a premium
>> price.
>>
>> You would unnecessarily burden manufactures
>> and consumer pocketbooks with unnecessary
>> expenses for including additional head amp
>> sections in players. There is no market for this.
>>
>>
>> > A better solution is a source which is capable
>> > of rated output without distortion/clipping or
>> > whatever problem your POS adjustable
>> > output level CD players have.
>> >
>> I wasn't aware there were problems with players
>> not outputing at line level (1-2 Vrms). There
>> is no practical use for playing devices outputing
>> at any higher levels. When they do that's when
>> a pot is often included on the device.
>
>
> Moron claims his Sony player doesn't even have the balls for line
> level output.
>
> reference his response to Bret's comment:
>
>> Most power amps will go full output with 1.5V rms. VTL in their book
>> specify they design for input sensitivity of 775 mV as I recall.
>
> Morons response:
> Yes, but from practical experience with Sony ES players, I can tell you
> that
> those with 5532 outputs cannot do it cleanly.
>
> So I have a couple issues with Bob's premise.
> 1) His crappy CD can't even provide std line level output cleanly.
> 2) Attenuating said output with a pot isn't likely to do anything to
> clean it up.
> 3) Adding extra gain later to compensate will also amplify the noise
> floor of the player reducing overall system S/N.
>
> ScottW
>
Scott, it sounds alot better with the preamp in. That's all I care about.
Noise is not a subjective problem in either system.
Without the preamp buffers, the systems sound strained.
I use Sony ES players, known to have excellent DACs, but not the best output
stages.
I also use Sony digital synthesizers, which have the same problem.
It works for me, so I recommend it to other people
I do not guarantee that they will be as satisfied as I am.

[ScottW]

Robert Morein wrote:
> "ScottW" > wrote in message
> ups.com...
> >
> > Powell wrote:
> >> "ScottW" wrote
> >>
> >> > If you must compensate a limited signal
> >> > level source with more gain in your preamp
> >> > then you are obviously also amplifying the
> >> > noise of your source more than should be
> >> > necessary and diminishing overall system
> >> > signal/noise ratio.
> >> >
> >> Well, yes and no.
> >>
> >> The volume pot is primarily used on players like
> >> CD/DVD, phonograph head amps, tuners, etc.,
> >> to slightly increase or reduce RMS voltage of
> >> the player's line level outputs. For the most
> >> part the consumer electronics industry sets
> >> *fixed outputs/line level* at 1-2 volts.
> >>
> >> There are plenty of alternative hybrids that
> >> output much higher by providing preamp output
> >> levels (5-50 Vrms). A few adequate products
> >> were sited. Because there is so little demand
> >> for these hybrids consumers pay a premium
> >> price.
> >>
> >> You would unnecessarily burden manufactures
> >> and consumer pocketbooks with unnecessary
> >> expenses for including additional head amp
> >> sections in players. There is no market for this.
> >>
> >>
> >> > A better solution is a source which is capable
> >> > of rated output without distortion/clipping or
> >> > whatever problem your POS adjustable
> >> > output level CD players have.
> >> >
> >> I wasn't aware there were problems with players
> >> not outputing at line level (1-2 Vrms). There
> >> is no practical use for playing devices outputing
> >> at any higher levels. When they do that's when
> >> a pot is often included on the device.
> >
> >
> > Moron claims his Sony player doesn't even have the balls for line
> > level output.
> >
> > reference his response to Bret's comment:
> >
> >> Most power amps will go full output with 1.5V rms. VTL in their book
> >> specify they design for input sensitivity of 775 mV as I recall.
> >
> > Morons response:
> > Yes, but from practical experience with Sony ES players, I can tell you
> > that
> > those with 5532 outputs cannot do it cleanly.
> >
> > So I have a couple issues with Bob's premise.
> > 1) His crappy CD can't even provide std line level output cleanly.
> > 2) Attenuating said output with a pot isn't likely to do anything to
> > clean it up.
> > 3) Adding extra gain later to compensate will also amplify the noise
> > floor of the player reducing overall system S/N.
> >
> > ScottW
> >
> Scott, it sounds alot better with the preamp in. That's all I care about.

That's fine. In the future we'll ignore anything but your subjective
appraisals as that is all you care about.

> Noise is not a subjective problem in either system.
> Without the preamp buffers, the systems sound strained.
> I use Sony ES players, known to have excellent DACs, but not the best output
> stages.

So your comments about passive attenuators really only applies to Sony
ES CD players which you find lacking in output performance. Maybe you
should have said that.

ScottW

[Robert Morein]

"ScottW" > wrote in message
oups.com...
>
> Robert Morein wrote:
>> "ScottW" > wrote in message
>> ups.com...
>> >
>> > Powell wrote:
>> >> "ScottW" wrote
>> >>
>> >> > If you must compensate a limited signal
>> >> > level source with more gain in your preamp
>> >> > then you are obviously also amplifying the
>> >> > noise of your source more than should be
>> >> > necessary and diminishing overall system
>> >> > signal/noise ratio.
>> >> >
>> >> Well, yes and no.
>> >>
>> >> The volume pot is primarily used on players like
>> >> CD/DVD, phonograph head amps, tuners, etc.,
>> >> to slightly increase or reduce RMS voltage of
>> >> the player's line level outputs. For the most
>> >> part the consumer electronics industry sets
>> >> *fixed outputs/line level* at 1-2 volts.
>> >>
>> >> There are plenty of alternative hybrids that
>> >> output much higher by providing preamp output
>> >> levels (5-50 Vrms). A few adequate products
>> >> were sited. Because there is so little demand
>> >> for these hybrids consumers pay a premium
>> >> price.
>> >>
>> >> You would unnecessarily burden manufactures
>> >> and consumer pocketbooks with unnecessary
>> >> expenses for including additional head amp
>> >> sections in players. There is no market for this.
>> >>
>> >>
>> >> > A better solution is a source which is capable
>> >> > of rated output without distortion/clipping or
>> >> > whatever problem your POS adjustable
>> >> > output level CD players have.
>> >> >
>> >> I wasn't aware there were problems with players
>> >> not outputing at line level (1-2 Vrms). There
>> >> is no practical use for playing devices outputing
>> >> at any higher levels. When they do that's when
>> >> a pot is often included on the device.
>> >
>> >
>> > Moron claims his Sony player doesn't even have the balls for line
>> > level output.
>> >
>> > reference his response to Bret's comment:
>> >
>> >> Most power amps will go full output with 1.5V rms. VTL in their book
>> >> specify they design for input sensitivity of 775 mV as I recall.
>> >
>> > Morons response:
>> > Yes, but from practical experience with Sony ES players, I can tell you
>> > that
>> > those with 5532 outputs cannot do it cleanly.
>> >
>> > So I have a couple issues with Bob's premise.
>> > 1) His crappy CD can't even provide std line level output cleanly.
>> > 2) Attenuating said output with a pot isn't likely to do anything to
>> > clean it up.
>> > 3) Adding extra gain later to compensate will also amplify the noise
>> > floor of the player reducing overall system S/N.
>> >
>> > ScottW
>> >
>> Scott, it sounds alot better with the preamp in. That's all I care about.
>
> That's fine. In the future we'll ignore anything but your subjective
> appraisals as that is all you care about.
>
>> Noise is not a subjective problem in either system.
>> Without the preamp buffers, the systems sound strained.
>> I use Sony ES players, known to have excellent DACs, but not the best
>> output
>> stages.
>
> So your comments about passive attenuators really only applies to Sony
> ES CD players which you find lacking in output performance.

No.

Maybe you
> should have said that.
>
> ScottW
>
It depends upon the player. Most Japanese players, and preamps, use
inadequate ouput circuitry. I disassembled a very fancy Pioneer Elite
preamp, and found 5532 outputs. The power supply was really tiny, using the
78XX regulators in TO-92 package. Some highly thought of Marantz players
also use them. The user has the choicee of modding, or using with a preamp
that has a good line driver output stage.

On the other hand, I disassembled a Yamaha economy preamp that had op-amps
throughout, but had good discrete line drivers, so it doesn't need the
treatment. All Yamaha preamps appear to have at least adequate outputs. The
C-50,60,70,80, and 85 have an output impedance of 15 ohms. One couldn't ask
for more than that.

The same shortcoming applies to several Sony digital processing preamps.
Some of these are still widely used by surround enthusiasts, like myself.
These include: TA-E1000ESD, TA-E2000ESD, EP9ES. All these pieces give good
or excellent sound, if buffered by a good preamp.

[ScottW]

Robert Morein wrote:
> "ScottW" > wrote in message
> oups.com...
> >
> > Robert Morein wrote:
> >> "ScottW" > wrote in message
> >> ups.com...
> >> >
> >> > Powell wrote:
> >> >> "ScottW" wrote
> >> >>
> >> >> > If you must compensate a limited signal
> >> >> > level source with more gain in your preamp
> >> >> > then you are obviously also amplifying the
> >> >> > noise of your source more than should be
> >> >> > necessary and diminishing overall system
> >> >> > signal/noise ratio.
> >> >> >
> >> >> Well, yes and no.
> >> >>
> >> >> The volume pot is primarily used on players like
> >> >> CD/DVD, phonograph head amps, tuners, etc.,
> >> >> to slightly increase or reduce RMS voltage of
> >> >> the player's line level outputs. For the most
> >> >> part the consumer electronics industry sets
> >> >> *fixed outputs/line level* at 1-2 volts.
> >> >>
> >> >> There are plenty of alternative hybrids that
> >> >> output much higher by providing preamp output
> >> >> levels (5-50 Vrms). A few adequate products
> >> >> were sited. Because there is so little demand
> >> >> for these hybrids consumers pay a premium
> >> >> price.
> >> >>
> >> >> You would unnecessarily burden manufactures
> >> >> and consumer pocketbooks with unnecessary
> >> >> expenses for including additional head amp
> >> >> sections in players. There is no market for this.
> >> >>
> >> >>
> >> >> > A better solution is a source which is capable
> >> >> > of rated output without distortion/clipping or
> >> >> > whatever problem your POS adjustable
> >> >> > output level CD players have.
> >> >> >
> >> >> I wasn't aware there were problems with players
> >> >> not outputing at line level (1-2 Vrms). There
> >> >> is no practical use for playing devices outputing
> >> >> at any higher levels. When they do that's when
> >> >> a pot is often included on the device.
> >> >
> >> >
> >> > Moron claims his Sony player doesn't even have the balls for line
> >> > level output.
> >> >
> >> > reference his response to Bret's comment:
> >> >
> >> >> Most power amps will go full output with 1.5V rms. VTL in their book
> >> >> specify they design for input sensitivity of 775 mV as I recall.
> >> >
> >> > Morons response:
> >> > Yes, but from practical experience with Sony ES players, I can tell you
> >> > that
> >> > those with 5532 outputs cannot do it cleanly.
> >> >
> >> > So I have a couple issues with Bob's premise.
> >> > 1) His crappy CD can't even provide std line level output cleanly.
> >> > 2) Attenuating said output with a pot isn't likely to do anything to
> >> > clean it up.
> >> > 3) Adding extra gain later to compensate will also amplify the noise
> >> > floor of the player reducing overall system S/N.
> >> >
> >> > ScottW
> >> >
> >> Scott, it sounds alot better with the preamp in. That's all I care about.
> >
> > That's fine. In the future we'll ignore anything but your subjective
> > appraisals as that is all you care about.
> >
> >> Noise is not a subjective problem in either system.
> >> Without the preamp buffers, the systems sound strained.
> >> I use Sony ES players, known to have excellent DACs, but not the best
> >> output
> >> stages.
> >
> > So your comments about passive attenuators really only applies to Sony
> > ES CD players which you find lacking in output performance.
>
> No.
>
> Maybe you
> > should have said that.
> >
> > ScottW
> >
> It depends upon the player. Most Japanese players, and preamps, use
> inadequate ouput circuitry. I disassembled a very fancy Pioneer Elite
> preamp, and found 5532 outputs. The power supply was really tiny, using the
> 78XX regulators in TO-92 package. Some highly thought of Marantz players
> also use them. The user has the choicee of modding, or using with a preamp
> that has a good line driver output stage.

Do these Marantz players have volume control?
Most preamps have similar input impedance to an amplifier so
adding a preamp won't change anything at the output of a CD player
with fixed levels.
I think you're straining more than your CD player.

ScottW

[Robert Morein]

"François Yves Le Gal" > wrote in message
...
> On Tue, 13 Dec 2005 18:58:01 -0500, "Robert Morein" >
> wrote:
>
>> I disassembled a very fancy Pioneer Elite
>>preamp, and found 5532 outputs.
>
> A properly used 5532 is able to swing ± 13 V on a 2 K load with a typical
> ±
> 15 V supply voltage...
>
>>The power supply was really tiny, using the
>>78XX regulators in TO-92 package.
>
> At 8 mA of supply current per OP amp and 100 mA of available output
> current
> per 78XX or 79XXin TO-92 form why should you need anything larger?
>
IME, 2K is not adequate for more than short runs.

[Arny Krueger]

"Robert Morein" > wrote in message
...
>
> "Bret Ludwig" > wrote in message
> oups.com...
>>
>> Powell wrote:
>>
>>> > A "passive preamp" is no such thing at all. It is a
>>> > selector/attenuator, acting as a signal switching
>>> > box and a variable signal attenuator.
>>> >
>>> True, and as a result most outboard devices like
>>> CD players, tuners, etc. lack enough RMS
>>> voltage to adequately drive power amps. Most
>>> mainstream preamps will output 5-50 volts.
>>
>> Most power amps will go full output with 1.5V rms. VTL in their book
>> specify they design for input sensitivity of 775 mV as I recall.

> Yes, but from practical experience with Sony ES players, I can tell you
> that those with 5532 outputs cannot do it cleanly.


In fact NE5532's can drive 7.75 volts into a 500 ohm load with exceptionally
low distortion as shown by the following authoritative reference:

http://www.dself.dsl.pipex.com/ampins/webbop/5532.htm

[Arny Krueger]

"ScottW" > wrote in message
ups.com...

> Moron claims his Sony player doesn't even have the balls for line
> level output.

The man says a lot of crazy things.

> reference his response to Bret's comment:
>
>> Most power amps will go full output with 1.5V rms. VTL in their book
>> specify they design for input sensitivity of 775 mV as I recall.
>
> Morons response:
> Yes, but from practical experience with Sony ES players, I can tell you
> that those with 5532 outputs cannot do it cleanly.

In fact NE5532's can drive 7.75 volts into a 500 ohm load with exceptionally
low distortion as shown by the following authoritative reference:

http://www.dself.dsl.pipex.com/ampins/webbop/5532.htm

7.75 volts is about 14 dB higher than the input sensitivity of a typical
power amp. IOW if you apply a signal that peaks at 7.75 volts to most power
amps, the amp is way far into clipping.

It's possible that Bob is basing his thesis on equipment that is simply
defective or otherwise not living up to its potential.

> So I have a couple issues with Bob's premise.

> 1) His crappy CD can't even provide std line level output cleanly.

In my experience Bob suffers from hysteria which causes him to leap from
faulty conclusion to faulty conclusion (example given above).

The usual problem with driving power amps directly from CD players is that
while there is more than enough gain to drive the power amp to full output
and maybe a few dB into clipping on the loudest passages, people are used to
working with active preamps with about 20 dB of gain. A lot of this gain is
sacrificed by the fact that most people aren't comfortable turning the gain
full up, to about 5 o'clock. IME most people's perceived comfortable full
output is about 1 o'clock.

> 2) Attenuating said output with a pot isn't likely to do anything to
> clean it up.

Agreed.

> 3) Adding extra gain later to compensate will also amplify the noise
> floor of the player reducing overall system S/N.

Any subsequent linear gain will elevate the signal and the noise
identically, which would maintain system SNR or dynamic range. Losses are
due to any noise that is added by the gain stage itself.

[Robert Morein]

"Arny Krueger" > wrote in message
...
>
said a lot of false things.

[Arny Krueger]

"Robert Morein" > wrote in message
...
>
> "François Yves Le Gal" > wrote in message
> ...

>> On Tue, 13 Dec 2005 18:58:01 -0500, "Robert Morein" >
>> wrote:

>>> I disassembled a very fancy Pioneer Elite preamp, and found 5532
>>> outputs.

Good stuff!

>> A properly used 5532 is able to swing ± 13 V on a 2 K load with a typical
>> ± 15 V supply voltage...

Or, 7.75 vrms with a 500 ohm load with vanishing distortion per Doug Self.

Experienced audio engineers know that a 5532 can do nothing if it can't
drive low impedance loads. If you took the 5532s out of pro audio about 25%
of everything would stop working.

>>>The power supply was really tiny, using the
>>>78XX regulators in TO-92 package.

Note Morein is eyeballing parts with untrained eyes - if a part is too small
for his uneducated, unpracticed eye, it can't handle audio well.

>> At 8 mA of supply current per OP amp and 100 mA of available output
>> current
>> per 78XX or 79XXin TO-92 form why should you need anything larger?

Agreed.

> IME, 2K is not adequate for more than short runs.

Note, Morein has ignorantly confused load impedance and source impedance.

I doubt that he can give a cogent explanation of the difference.

Remember, Morien is a guy who places himself over degreed engineers, at
least in his own mind and RAO posts.

[Arny Krueger]

"ScottW" > wrote in message
ups.com...
>
> Robert Morein wrote:
>> "ScottW" > wrote in message
>> oups.com...
>> >
>> > Robert Morein wrote:
>> >> "ScottW" > wrote in message
>> >> ups.com...
>> >> >
>> >> > Powell wrote:
>> >> >> "ScottW" wrote
>> >> >>
>> >> >> > If you must compensate a limited signal
>> >> >> > level source with more gain in your preamp
>> >> >> > then you are obviously also amplifying the
>> >> >> > noise of your source more than should be
>> >> >> > necessary and diminishing overall system
>> >> >> > signal/noise ratio.
>> >> >> >
>> >> >> Well, yes and no.
>> >> >>
>> >> >> The volume pot is primarily used on players like
>> >> >> CD/DVD, phonograph head amps, tuners, etc.,
>> >> >> to slightly increase or reduce RMS voltage of
>> >> >> the player's line level outputs. For the most
>> >> >> part the consumer electronics industry sets
>> >> >> *fixed outputs/line level* at 1-2 volts.
>> >> >>
>> >> >> There are plenty of alternative hybrids that
>> >> >> output much higher by providing preamp output
>> >> >> levels (5-50 Vrms). A few adequate products
>> >> >> were sited. Because there is so little demand
>> >> >> for these hybrids consumers pay a premium
>> >> >> price.
>> >> >>
>> >> >> You would unnecessarily burden manufactures
>> >> >> and consumer pocketbooks with unnecessary
>> >> >> expenses for including additional head amp
>> >> >> sections in players. There is no market for this.
>> >> >>
>> >> >>
>> >> >> > A better solution is a source which is capable
>> >> >> > of rated output without distortion/clipping or
>> >> >> > whatever problem your POS adjustable
>> >> >> > output level CD players have.
>> >> >> >
>> >> >> I wasn't aware there were problems with players
>> >> >> not outputing at line level (1-2 Vrms). There
>> >> >> is no practical use for playing devices outputing
>> >> >> at any higher levels. When they do that's when
>> >> >> a pot is often included on the device.
>> >> >
>> >> >
>> >> > Moron claims his Sony player doesn't even have the balls for line
>> >> > level output.
>> >> >
>> >> > reference his response to Bret's comment:
>> >> >
>> >> >> Most power amps will go full output with 1.5V rms. VTL in their
>> >> >> book
>> >> >> specify they design for input sensitivity of 775 mV as I recall.
>> >> >
>> >> > Morons response:
>> >> > Yes, but from practical experience with Sony ES players, I can tell
>> >> > you
>> >> > that
>> >> > those with 5532 outputs cannot do it cleanly.
>> >> >
>> >> > So I have a couple issues with Bob's premise.
>> >> > 1) His crappy CD can't even provide std line level output cleanly.
>> >> > 2) Attenuating said output with a pot isn't likely to do anything to
>> >> > clean it up.
>> >> > 3) Adding extra gain later to compensate will also amplify the
>> >> > noise
>> >> > floor of the player reducing overall system S/N.
>> >> >
>> >> > ScottW
>> >> >
>> >> Scott, it sounds alot better with the preamp in. That's all I care
>> >> about.
>> >
>> > That's fine. In the future we'll ignore anything but your subjective
>> > appraisals as that is all you care about.
>> >
>> >> Noise is not a subjective problem in either system.
>> >> Without the preamp buffers, the systems sound strained.
>> >> I use Sony ES players, known to have excellent DACs, but not the best
>> >> output
>> >> stages.
>> >
>> > So your comments about passive attenuators really only applies to Sony
>> > ES CD players which you find lacking in output performance.
>>
>> No.
>>
>> Maybe you
>> > should have said that.
>> >
>> > ScottW
>> >
>> It depends upon the player. Most Japanese players, and preamps, use
>> inadequate ouput circuitry. I disassembled a very fancy Pioneer Elite
>> preamp, and found 5532 outputs. The power supply was really tiny, using
>> the
>> 78XX regulators in TO-92 package. Some highly thought of Marantz players
>> also use them. The user has the choicee of modding, or using with a
>> preamp
>> that has a good line driver output stage.
>
> Do these Marantz players have volume control?
> Most preamps have similar input impedance to an amplifier so
> adding a preamp won't change anything at the output of a CD player
> with fixed levels.
> I think you're straining more than your CD player.

Given how easily and thoroughly Francois and I deconstructed Morein, all
he's straining is his credibility, which is pretty well shot already.

[Arny Krueger]

"Robert Morein" > wrote in message
...

> "Arny Krueger" > wrote in message
> ...


>> "ScottW" > wrote in message
>> ups.com...

>>> Moron claims his Sony player doesn't even have the balls for line
>>> level output.

>> The man says a lot of crazy things.

>> reference his response to Bret's comment:

>>> Most power amps will go full output with 1.5V rms. VTL in their book
>>> specify they design for input sensitivity of 775 mV as I recall.

>> Morons response:

>>> Yes, but from practical experience with Sony ES players, I can tell you
>>> that those with 5532 outputs cannot do it cleanly.

>> In fact NE5532's can drive 7.75 volts into a 500 ohm load with
>> exceptionally
>> low distortion as shown by the following authoritative reference:

>> http://www.dself.dsl.pipex.com/ampins/webbop/5532.htm

>> 7.75 volts is about 14 dB higher than the input sensitivity of a typical
>> power amp. IOW if you apply a signal that peaks at 7.75 volts to most
>> power amps, the amp is way far into clipping.

>> It's possible that Bob is basing his thesis on equipment that is simply
>> defective or otherwise not living up to its potential.

>>> So I have a couple issues with Bob's premise.

>>> 1) His crappy CD can't even provide std line level output cleanly.

>> In my experience Bob suffers from hysteria which causes him to leap from
>> faulty conclusion to faulty conclusion (example given above).

>> The usual problem with driving power amps directly from CD players is
>> that while there is more than enough gain to drive the power amp to full
>> output and maybe a few dB into clipping on the loudest passages, people
>> are used to working with active preamps with about 20 dB of gain. A lot
>> of this gain is sacrificed by the fact that most people aren't
>> comfortable turning the gain full up, to about 5 o'clock. IME most
>> people's perceived comfortable full output is about 1 o'clock.

>>> 2) Attenuating said output with a pot isn't likely to do anything to
>>> clean it up.

>> Agreed.

>>> 3) Adding extra gain later to compensate will also amplify the noise
>>> floor of the player reducing overall system S/N.

>> Any subsequent linear gain will elevate the signal and the noise
>> identically, which would maintain system SNR or dynamic range. Losses are
>> due to any noise that is added by the gain stage itself.

> said a lot of false things.

Prove it, Morien. Francois and I have deconstructed you pretty thoroughly.
Live with it!

[Arny Krueger]

"François Yves Le Gal" > wrote in message
...

> On Tue, 13 Dec 2005 21:27:12 -0500, "Robert Morein" >
> wrote:
>
>>IME, 2K is not adequate for more than short runs.
>
> Huh? What do you mean? A typical consumer amp shows an input R of more
> than
> 10 KOhms.

Actually, that's the standard EIA worst case input impedance for consumer
electronics. Many pieces have higher input impedances, often around 100K.

> A 5532 can swing nearly all the way to the rails in such a load...

Exactly!

[dizzy]

On Wed, 14 Dec 2005 01:23:30 +0100, François Yves Le Gal
> wrote:

>On Tue, 13 Dec 2005 18:58:01 -0500, "Robert Morein" >
>wrote:
>
>> I disassembled a very fancy Pioneer Elite
>>preamp, and found 5532 outputs.
>
>A properly used 5532 is able to swing ± 13 V on a 2 K load with a typical ±
>15 V supply voltage...
>
>>The power supply was really tiny, using the
>>78XX regulators in TO-92 package.
>
>At 8 mA of supply current per OP amp and 100 mA of available output current
>per 78XX or 79XXin TO-92 form why should you need anything larger?

Umm... So you can charge 5 freaking grand for what is essentially a
switch, a buffer amp, and a pot?

It's really amazing how expensive most preamps are, considering how
cheap and easy it is to do that function... Madness.

[Robert Morein]

"Arny Krueger" > wrote in message
...
>
> "Robert Morein" > wrote in message
> ...
>
>> "Arny Krueger" > wrote in message
>> ...
>
>
>>> "ScottW" > wrote in message
>>> ups.com...
>
>>>> Moron claims his Sony player doesn't even have the balls for line
>>>> level output.
>
>>> The man says a lot of crazy things.
>
>>> reference his response to Bret's comment:
>
>>>> Most power amps will go full output with 1.5V rms. VTL in their book
>>>> specify they design for input sensitivity of 775 mV as I recall.
>
>>> Morons response:
>
>>>> Yes, but from practical experience with Sony ES players, I can tell you
>>>> that those with 5532 outputs cannot do it cleanly.
>
>>> In fact NE5532's can drive 7.75 volts into a 500 ohm load with
>>> exceptionally
>>> low distortion as shown by the following authoritative reference:
>
>>> http://www.dself.dsl.pipex.com/ampins/webbop/5532.htm
>
>>> 7.75 volts is about 14 dB higher than the input sensitivity of a typical
>>> power amp. IOW if you apply a signal that peaks at 7.75 volts to most
>>> power amps, the amp is way far into clipping.
>
>>> It's possible that Bob is basing his thesis on equipment that is simply
>>> defective or otherwise not living up to its potential.
>
>>>> So I have a couple issues with Bob's premise.
>
>>>> 1) His crappy CD can't even provide std line level output cleanly.
>
>>> In my experience Bob suffers from hysteria which causes him to leap from
>>> faulty conclusion to faulty conclusion (example given above).
>
>>> The usual problem with driving power amps directly from CD players is
>>> that while there is more than enough gain to drive the power amp to full
>>> output and maybe a few dB into clipping on the loudest passages, people
>>> are used to working with active preamps with about 20 dB of gain. A lot
>>> of this gain is sacrificed by the fact that most people aren't
>>> comfortable turning the gain full up, to about 5 o'clock. IME most
>>> people's perceived comfortable full output is about 1 o'clock.
>
>>>> 2) Attenuating said output with a pot isn't likely to do anything to
>>>> clean it up.
>
>>> Agreed.
>
>>>> 3) Adding extra gain later to compensate will also amplify the noise
>>>> floor of the player reducing overall system S/N.
>
>>> Any subsequent linear gain will elevate the signal and the noise
>>> identically, which would maintain system SNR or dynamic range. Losses
>>> are due to any noise that is added by the gain stage itself.
>
>> said a lot of false things.
>
> Prove it, Morien. Francois and I have deconstructed you pretty
> thoroughly. Live with it!
I don't think Francois would like to be a party to this. Ask him.

[Powell]

"Arny Krueger" wrote

>> So I have a couple issues with Bob's premise.
>
>> 1) His crappy CD can't even provide std line level
>> output cleanly.
>
> In my experience Bob suffers from hysteria which
> causes him to leap from faulty conclusion to faulty
> conclusion (example given above).
>
What is the proper methodology for measuring
Vrms voltage from fixed RCA outputs on players?
Is there anything which would preclude Robert
from measuring it with a handheld volt meter
and test disk?

[ScottW]

Arny Krueger wrote:
> "ScottW" > wrote in message
>
> > 3) Adding extra gain later to compensate will also amplify the noise
> > floor of the player reducing overall system S/N.
>
> Any subsequent linear gain will elevate the signal and the noise
> identically, which would maintain system SNR or dynamic range. Losses are
> due to any noise that is added by the gain stage itself.

Agreed, but running the source at a very low output level will
prevent it from outputting optimal S/N ratio and the additional later
gain will also diminish noise (EMI) immunity.

ScottW

[ScottW]

Powell wrote:
> "Arny Krueger" wrote
>
> >> So I have a couple issues with Bob's premise.
> >
> >> 1) His crappy CD can't even provide std line level
> >> output cleanly.
> >
> > In my experience Bob suffers from hysteria which
> > causes him to leap from faulty conclusion to faulty
> > conclusion (example given above).
> >
> What is the proper methodology for measuring
> Vrms voltage from fixed RCA outputs on players?
> Is there anything which would preclude Robert
> from measuring it with a handheld volt meter
> and test disk?

Not that I can think of.

ScottW

[Arny Krueger]

"Powell" > wrote in message
...
>
> "Arny Krueger" wrote
>
>>> So I have a couple issues with Bob's premise.
>>
>>> 1) His crappy CD can't even provide std line level
>>> output cleanly.
>>
>> In my experience Bob suffers from hysteria which
>> causes him to leap from faulty conclusion to faulty
>> conclusion (example given above).
>>
> What is the proper methodology for measuring
> Vrms voltage from fixed RCA outputs on players?

EIA load, Test CD, reasonbly high impedance voltmeter with flat frequency
response.

> Is there anything which would preclude Robert
> from measuring it with a handheld volt meter
> and test disk?

The FR of the handheld voltmeter is a potential source of errors. Some are
only designed to work well with line voltage and are already a few dB down
at the standard frequencies of 400 Hz or 1 KHz.

>
>
>
>
>

[Arny Krueger]

"ScottW" > wrote in message
oups.com...
>
> Arny Krueger wrote:
>> "ScottW" > wrote in message
>>
>> > 3) Adding extra gain later to compensate will also amplify the noise
>> > floor of the player reducing overall system S/N.
>>
>> Any subsequent linear gain will elevate the signal and the noise
>> identically, which would maintain system SNR or dynamic range. Losses are
>> due to any noise that is added by the gain stage itself.
>
> Agreed, but running the source at a very low output level will
> prevent it from outputting optimal S/N ratio and the additional later
> gain will also diminish noise (EMI) immunity.

Agreed. It doesn't make sense to unnecessarily throw away signal without
some other larger benefit.

[Powell]

"Arny Krueger" wrote

>> What is the proper methodology for measuring
>> Vrms voltage from fixed RCA outputs on players?
>
> EIA load, Test CD, reasonbly high impedance
> voltmeter with flat frequency response.
>
So as I understand it, Robert, based on past
posts of technical capability shouldn't have any
problems generating this data? I’m in general
agreement with him, pots on input devices are
marginal at driving power amps. Providing
data seems like the least he could do to
support his assumption and mine.


>> Is there anything which would preclude Robert
>> from measuring it with a handheld volt meter
>> and test disk?
>
> The FR of the handheld voltmeter is a potential
> source of errors. Some are only designed to
> work well with line voltage and are already a
> few dB down at the standard frequencies of
> 400 Hz or 1 KHz.
>
Thank you.

[dizzy]

François Yves Le Gal wrote:

>On Wed, 14 Dec 2005 14:01:23 GMT, dizzy > wrote:
>>
>>It's really amazing how expensive most preamps are, considering how
>>cheap and easy it is to do that function... Madness.
>
>Well, you can use fancy parts and components. A quality generic two deck/six
>position switch costs around USD4.00, a fancy Elma 2/6 around USD20,00.
>
>Ditto for everything : an op amp costs only pennies in generic form, a high
>end model such as the Burr Brown OPA627 costs USD12.25 per 1 K. So it's
>pretty easy to reach a USD1,000.00 parts budget, translating into a retail
>price of USD10,000.00 or more!

Yes, but a preamp only needs one "big" switch, and just a few op-amp
chips, and 2-4 good pots. Not so "easy" to reach $1,000 parts cost
with the essential components, even when they are "fancy" - unless
they use a ridiculously over-built power supply and/or over-built
casework...

[dizzy]

dizzy wrote:

>François Yves Le Gal wrote:
>
>>On Wed, 14 Dec 2005 14:01:23 GMT, dizzy > wrote:
>>>
>>>It's really amazing how expensive most preamps are, considering how
>>>cheap and easy it is to do that function... Madness.
>>
>>Well, you can use fancy parts and components. A quality generic two deck/six
>>position switch costs around USD4.00, a fancy Elma 2/6 around USD20,00.
>>
>>Ditto for everything : an op amp costs only pennies in generic form, a high
>>end model such as the Burr Brown OPA627 costs USD12.25 per 1 K. So it's
>>pretty easy to reach a USD1,000.00 parts budget, translating into a retail
>>price of USD10,000.00 or more!
>
>Yes, but a preamp only needs one "big" switch, and just a few op-amp
>chips, and 2-4 good pots. Not so "easy" to reach $1,000 parts cost
>with the essential components, even when they are "fancy" - unless
>they use a ridiculously over-built power supply and/or over-built
>casework...

Note that I'm thinking of line-level preamps, here...