[Dave Smith[_2_]]

I recently ditched my Pioneer surround receiver for the simplicity of a
two channel amp, the Advent 300. I'm very happy with the simplicity
part but I did notice that while listening to some piano music the
mid-low range seemed kind of muddy to me. One person I spoke with
suggested that if the 300 had sat unused for a long period of time that
the sound quality will improve if it is left on for a week. Is this
true or did I simply buy something that isn't up to par? Perhaps I
should have considered a more modern amplifier.

Thanks,

Dave

[Sonnova]

On Tue, 30 Sep 2008 16:05:27 -0700, Dave Smith wrote
(in article ):

I recently ditched my Pioneer surround receiver for the simplicity of a
two channel amp, the Advent 300. I'm very happy with the simplicity
part but I did notice that while listening to some piano music the
mid-low range seemed kind of muddy to me. One person I spoke with
suggested that if the 300 had sat unused for a long period of time that
the sound quality will improve if it is left on for a week. Is this
true or did I simply buy something that isn't up to par? Perhaps I
should have considered a more modern amplifier.

Thanks,

Dave


I doubt that a modern amplifier will sound any different than a perfectly
functioning Advent 300. I suspect that what's happened and what the person
you spoke with was referring to, was the fact that if amps are left sitting
without being turned-on for a long time, the electrolytic capacitors in the
amp lose some of their polarity. This can, in many cases, be restored by
allowing the electrolyte to re-form over time which may reduce or eliminate
the anomaly that you are hearing. Of course, if the caps are too far gone,
there's nothing for it but to replace them.

Of course it could be dried-out coupling capacitors too. They will definitely
affect low frequency response as their capacitance drops. These would need
replacing.

[jwvm]

On Sep 30, 7:05*pm, Dave Smith wrote:
I recently ditched my Pioneer surround receiver for the simplicity of a
two channel amp, the Advent 300. I'm very happy with the simplicity
part but I did notice that while listening to some piano music the
mid-low range seemed kind of muddy to me. One person I spoke with
suggested that if the 300 had sat unused for a long period of time that
the sound quality will improve if it is left on for a week. Is this
true or did I simply buy something that isn't up to par?

It is possible that one or more of the capacitors may have degraded
over time. Leaving the unit on is not likely to improve them. It is
difficult to arrive at a definitive diagnosis from the problem that
you describe and you may not want to have the unit serviced given the
likely cost. Your Pioneer likely had much greater output power so
there could be some mild clipping or similar distortion, especially if
your speakers are relatively inefficient.

Perhaps I
should have considered a more modern amplifier.

Your Pioneer receiver was more modern and should have provided good
results. What was the problem with it?

[David L. Martel[_2_]]

jwvm,

Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

Dave M.

[Dave Smith[_2_]]

On 2008-10-01 02:04:28 -0700, jwvm said:


Your Pioneer receiver was more modern and should have provided good
results. What was the problem with it?

I decided that something simple, that I could just turn on and listen
to, would be more enjoyable for me. The Pioneer was all about buttons
and lights and surround sound, none of which I am interested in anymore.

Thank you for the responses I have received. I wish I was an
electronics guy so I could test and potentially repair the items
mentioned.

Dave

[jwvm]

On Oct 1, 6:25*pm, "David L. Martel" wrote:
jwvm,

* *Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

Dave M.

If the speakers are inefficient, then more power will be needed to
drive them. The pioneer likely had 50 or 100 watts/channel contrasted
with 15 watts/channel or so for the Advent and so could handle
inefficient speakers better. If the filter capacitors in the Advent
had degraded, then the power output could be considerably less. The OP
mentioned that certain musical passages sounded muddy, which could
indicate some intermodulation distortion. Without actual measurements,
this is only speculation.

[Eeyore]

Dave Smith wrote:

I recently ditched my Pioneer surround receiver for the simplicity of a
two channel amp, the Advent 300. I'm very happy with the simplicity
part but I did notice that while listening to some piano music the
mid-low range seemed kind of muddy to me. One person I spoke with
suggested that if the 300 had sat unused for a long period of time that
the sound quality will improve if it is left on for a week. Is this
true or did I simply buy something that isn't up to par? Perhaps I
should have considered a more modern amplifier.

Considering it's a 32 year old design, much has improved over the years.

I imagine EVERY electrolytic capacitor in it would benefit from being
replaced.

Graham

[Dave Smith[_2_]]

Also, the rca connections on the back are cloudy looking. What is the
best way to clean them?

Thanks,

Dave

[Dave Smith[_2_]]

On 2008-10-01 15:25:27 -0700, "David L. Martel" said:

jwvm,

Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

Dave M.

I only listen at low volume levels so I am very confident this is not
the issue. The speakers are Celestion Model 11's.

Dave

[Dave Smith[_2_]]

On 2008-10-02 05:59:44 -0700, jwvm said:

On Oct 1, 6:25*pm, "David L. Martel" wrote:
jwvm,

* *Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

Dave M.

If the speakers are inefficient, then more power will be needed to
drive them. The pioneer likely had 50 or 100 watts/channel contrasted
with 15 watts/channel or so for the Advent and so could handle
inefficient speakers better. If the filter capacitors in the Advent
had degraded, then the power output could be considerably less. The OP
mentioned that certain musical passages sounded muddy, which could
indicate some intermodulation distortion. Without actual measurements,
this is only speculation.

I'm starting to think the Advent was a big mistake. It doesn't sound
very good and apparently it would be expensive to fix since I can't do
electronic repairs myself. So what are my options? Ditch it completely
and start over with something new? Or should I keep it as a preamp and
buy an amplifier to go with it?

Thanks,

Dave

[Sonnova]

On Wed, 8 Oct 2008 15:14:57 -0700, Dave Smith wrote
(in article ):

On 2008-10-02 05:59:44 -0700, jwvm said:

On Oct 1, 6:25*pm, "David L. Martel" wrote:
jwvm,

* *Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

Dave M.

If the speakers are inefficient, then more power will be needed to
drive them. The pioneer likely had 50 or 100 watts/channel contrasted
with 15 watts/channel or so for the Advent and so could handle
inefficient speakers better. If the filter capacitors in the Advent
had degraded, then the power output could be considerably less. The OP
mentioned that certain musical passages sounded muddy, which could
indicate some intermodulation distortion. Without actual measurements,
this is only speculation.

I'm starting to think the Advent was a big mistake. It doesn't sound
very good and apparently it would be expensive to fix since I can't do
electronic repairs myself. So what are my options? Ditch it completely
and start over with something new? Or should I keep it as a preamp and
buy an amplifier to go with it?

Thanks,

Dave


How does the preamp part of it sound? Could be the problem is there and not
in the power-amp part of the unit. If so, using it as a preamp won't help you
with the sound at all. OTOH, if the preamp part sounds good (and gives you a
pre-amp output) then Buy yourself a Behringer A-500 Power amp (160 WPC into
8 ohms) at about $200 street price and don't look back.

[Peter Wieck]

On Oct 2, 9:15*pm, Dave Smith wrote:
Also, the rca connections on the back are cloudy looking. What is the
best way to clean them?

Thanks,

Dave

OK....

The best method to clean RCA jacks is a mildly abrasive cloth with a
mild strength contact cleaner. So, your wife's softest emery board and
91% alcohol will do just fine.

As to the Advent 300 itself, and assuming perfect function:

It has a nominal 15wpc/rms at whatever distortion-figures-picked-
before-clipping. The reality is probably very slightly more than that,
but use 15 watts.

To get anything that is significantly and perceptably more powerful
than that you would need _AT LEAST_ 100 watts or more.

Why?

Assume a nominal speaker efficiency of 1watt = 87dB (Typical
inefficient speaker on the order of vintage ARs or KLH or Advents).

To get 97dB (twice as loud), 10 watts would be required. The Advent
will handle it fine.

To get 107dB, 100 watts would be required. Neither the Advent nor the
Pioneer will achieve that. That is pretty LOUD.

Assume that the Pioneer is 60 watts. That would get you to 101dB or
so. The advent gets you to about 97.5dB or so. There is not a very
large difference here.

Of course, if you are used to listening to sources with a 20+dB peak-
to-average ratio at substantial volumes into very inefficient speakers
(typical to my case, as it happens), neither receiver will do you much
good and you will have to move to a Brute Force amp of some nature
(and in my case, I keep a Citation 16 for that purpose - it drives the
maggies just fine).

Note that the Advent, when originally sold was not touted a the be/end
all of receivers, but as a very nice tuner/pre-amp that would serve as
a receiver until its buyer could afford a separate power-amp at a
later time. As it happens, they did also make an Advent 350, a much
more powerful receiver in small numbers, and a 12V version of the 300
in even smaller numbers designed for RVs.

Don't be disappointed in its power if the tuner/pre-amp sections are
functioning properly. Those are its strong points.

Peter Wieck
Melrose Park, PA

[Peter Wieck]

On Oct 1, 6:25*pm, Dave Smith wrote:
On 2008-10-01 02:04:28 -0700, jwvm said:



Your Pioneer receiver was more modern and should have provided good
results. What was the problem with it?

I decided that something simple, that I could just turn on and listen
to, would be more enjoyable for me. The Pioneer was all about buttons
and lights and surround sound, none of which I am interested in anymore.

Thank you for the responses I have received. I wish I was an
electronics guy so I could test and potentially repair the items
mentioned.

Dave

Look for an AR Model R or W Receiver (and hold out for the Gorler
front-end if you can). About as simple a receiver as it gets, but with
about the same power or greater as the Pioneer. I keep two of these
for my several secondary stereos, and have three out on loan to
friends-and-family. Most of them should also be recapped (1971
vintage), but as they are 50% point-to-point and 50% boards, this can
be a minor PITA. I also arbitrarily replace the outputs (2N3055) with
matched sets - seems to make a very small difference. On my primary
unit, I also matched the drivers because I could - seems to make a
small difference, both of which could be entirely wishful thinking.
Replacing the 1uF electrolytics on the tone and driver boards with
screened and tested 1uF 150V film caps makes a *big* difference.

And, the Advent is all-one-big-board inside with pretty much
everything easily reached and serviced. It isn't rocket science, the
schematic is printed on the bottom (or should be), just mind
polarities when you replace caps and mind also that in small-signal
applications, capacitance value is critical (there is a difference in
how the unit will sound if you replace a 1uF cap with a 10uF cap).
Make sure that replacement caps are at the same voltage rating or
better. I have recapped these beasts, and it takes about 90 minutes to
get all the critical caps if you are slow and careful. Did I suggest
that you *MIND POLARITY*? It also helps to screen the caps ahead of
time to make sure that they are on-value. Electrolytics (unless
otherwise marked) may be -20%/+100% in tolerance and still be "on-
spec".

Point being that if you are going to get into vintage equipment, you
will need to learn how to do some small things in self-defense or be
subject to expensive service costs (and possible rip-offs as well), or
expensive failures. Recapping _EVERY_ electrolytic in an AR receiver
will cost you about $20 for very good quality replacement caps. Less
than a diagnosis-fee from a service tech. And a similarly treated
Advent will cost you slightly less.

Mouser, DigiKey, Newark & Santech are good sources of caps as well as
electronic parts of all types.

Peter Wieck
Melrose Park, PA

[Eeyore]

Dave Smith wrote:

"David L. Martel" said:
jwvm,

Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

I only listen at low volume levels so I am very confident this is not
the issue.

How low ? Do you have a dB meter ?
http://www.radioshack.com/sm-digital...i-2103667.html
Quite adequate for this job. I have the older meter movement version.

It will under-read peaks significantly btw (even on 'fast'). Dpending on your
kind of music add say 10dB) - and use it with C weighting NOT A.


The speakers are Celestion Model 11's.

And the sensitivity of these is ? From such data you can CALCULATE the required
wattage.

Graham

[Eeyore]

Sonnova wrote:

Dave Smith wrote
jwvm said:
"David L. Martel" wrote:
jwvm,

Why would you suspect clipping or distortion in the less powerful Advent
amp caused by inefficient speakers? Or am I misunderstanding you?

If the speakers are inefficient, then more power will be needed to
drive them. The pioneer likely had 50 or 100 watts/channel contrasted
with 15 watts/channel or so for the Advent and so could handle
inefficient speakers better. If the filter capacitors in the Advent
had degraded, then the power output could be considerably less. The OP
mentioned that certain musical passages sounded muddy, which could
indicate some intermodulation distortion. Without actual measurements,
this is only speculation.

I'm starting to think the Advent was a big mistake. It doesn't sound
very good and apparently it would be expensive to fix since I can't do
electronic repairs myself. So what are my options? Ditch it completely
and start over with something new? Or should I keep it as a preamp and
buy an amplifier to go with it?

How does the preamp part of it sound?

Pretty unlikely. It's a low component count discrete design classic of the 70s era.
Long superseded by better things.

Could be the problem is there and not
in the power-amp part of the unit. If so, using it as a preamp won't help you
with the sound at all. OTOH, if the preamp part sounds good (and gives you a
pre-amp output) then Buy yourself a Behringer A-500 Power amp (160 WPC into
8 ohms) at about $200 street price and don't look back.

Dump the Advent totally. Trying to get a decent sound out of a work-out antique (it
would at minimum need total recapping of the electrolytic caps) is a mug's game.

Get something nice and new *with enough power to drive your speakers too*. The
Behringer power amp's a possibility (who makes standalone pre-amps ?) but I've had
poor experience of Behringer product reliability.

Graham