Loss of one channel

[Bob Landry]

Just deleted rec.audio.misc. since it seems to be populated by folks who can't
seem to find *.*.politics. This groups seems to have folks who are actually
interested in and knowledgeable about audio. I'm in the "interested" group, but
not in the "knowledgeable" group.

I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver power
amp. I seem to have recently lost the right channel; moving the balance knob all
the way to the right has no effect. I'm running the Carver into 2 Polk speakers,
where I've used all 4 terminals on each, running two lines into each of the 4
outputs on the Carver. I've checked and rechecked the connections, and they're
all done the way the Polk instructions describe.

Is there any way to tell whether the problem is with the Dynaco or the Carver
without taking it to a shop? The drop off occurs with the CD player and the FM
tuner, also a Dynaco, so I think it's safe to say that the problem is with the
electronics and not the speakers, right?

Any help for a new member and an electronic ignoramus greatly appreciated.

Bob

[Richard Crowley]

"Bob Landry" wrote ...
> Just deleted rec.audio.misc. since it seems to be populated by folks who
> can't
> seem to find *.*.politics. This groups seems to have folks who are
> actually
> interested in and knowledgeable about audio. I'm in the "interested"
> group, but
> not in the "knowledgeable" group.
>
> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
> power
> amp. I seem to have recently lost the right channel; moving the balance
> knob all
> the way to the right has no effect. I'm running the Carver into 2 Polk
> speakers,
> where I've used all 4 terminals on each, running two lines into each of
> the 4
> outputs on the Carver. I've checked and rechecked the connections, and
> they're
> all done the way the Polk instructions describe.
>
> Is there any way to tell whether the problem is with the Dynaco or the
> Carver
> without taking it to a shop? The drop off occurs with the CD player and
> the FM
> tuner, also a Dynaco, so I think it's safe to say that the problem is with
> the
> electronics and not the speakers, right?
>
> Any help for a new member and an electronic ignoramus greatly appreciated.

The easiest way to identify whether the problem is in the preamp or
in the power amp is to simply switch right/left between them. If the
problem moves to the other side, then it is the preamp, if not, then
it is the power amp.

Do you have the technical info (schematic diagram, etc.) for either
equipment?

[Bob Landry]

On Wed, 16 Sep 2009 15:34:06 -0700, "Richard Crowley" >
wrote:

>"Bob Landry" wrote ...
>> Just deleted rec.audio.misc. since it seems to be populated by folks who
>> can't
>> seem to find *.*.politics. This groups seems to have folks who are
>> actually
>> interested in and knowledgeable about audio. I'm in the "interested"
>> group, but
>> not in the "knowledgeable" group.
>>
>> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
>> power
>> amp. I seem to have recently lost the right channel; moving the balance
>> knob all
>> the way to the right has no effect. I'm running the Carver into 2 Polk
>> speakers,
>> where I've used all 4 terminals on each, running two lines into each of
>> the 4
>> outputs on the Carver. I've checked and rechecked the connections, and
>> they're
>> all done the way the Polk instructions describe.
>>
>> Is there any way to tell whether the problem is with the Dynaco or the
>> Carver
>> without taking it to a shop? The drop off occurs with the CD player and
>> the FM
>> tuner, also a Dynaco, so I think it's safe to say that the problem is with
>> the
>> electronics and not the speakers, right?
>>
>> Any help for a new member and an electronic ignoramus greatly appreciated.
>
>The easiest way to identify whether the problem is in the preamp or
>in the power amp is to simply switch right/left between them. If the
>problem moves to the other side, then it is the preamp, if not, then
>it is the power amp.
>
>Do you have the technical info (schematic diagram, etc.) for either
>equipment?
>

Nope, but I just solved my problem, which I could have done without bothering
the group.

I simply went back to a conventional speaker wiring setup, replacing the
terminal bridges on the Polks. So I still have no idea what the problem was, but
now I have stereo again, and am a happy listener!

Now, if I can just get rid of that hum......only noticeable with now signal
going into the pre-amp, I'm hoping it's just cheap cables between the preamp out
and the power amp in.

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[Dave Platt]

In article >,
Bob Landry > wrote:

>Just deleted rec.audio.misc. since it seems to be populated by folks who can't
>seem to find *.*.politics. This groups seems to have folks who are actually
>interested in and knowledgeable about audio. I'm in the "interested" group, but
>not in the "knowledgeable" group.
>
>I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver power
>amp. I seem to have recently lost the right channel; moving the balance knob all
>the way to the right has no effect. I'm running the Carver into 2 Polk speakers,
>where I've used all 4 terminals on each, running two lines into each of the 4
>outputs on the Carver. I've checked and rechecked the connections, and they're
>all done the way the Polk instructions describe.
>
>Is there any way to tell whether the problem is with the Dynaco or the Carver
>without taking it to a shop? The drop off occurs with the CD player and the FM
>tuner, also a Dynaco, so I think it's safe to say that the problem is with the
>electronics and not the speakers, right?

The fact that it affects both the CD player and the FM tuner indicates
that the problem isn't in either of those components, or in the cables
connecting them to the Dynaco. It's "downstream"... at the Dynaco or
later... but you haven't eliminated the speakers as the possible
problem (although it's

Swap the left and right channel cable connections where they come out
of the Dynaco (with the power off everywhere, of course) and see what
the effect is.

If the problem moves to the opposite channel, then it's either in the
Dynaco, or in the Dynaco-end connectors of the cable. Distinguish
these two cases by trying a different cable... problem goes away (you
had a bad cable) or problem remains (bad Dynaco).

On the other hand, if the problem stays the same, then it's either in
the cable itself, in the connectors at the Carver end of the cable, in
the Carver, or somewhere downstream (e.g. speaker cables or speakers).
Swap the Dynaco-to-Carver cable with a known-good one to rule out a
cable problem, then figure out whether the problem is in the Carver or
the speakers.

You might have blown a fuse in the Carver, due to (e.g.) running
low-impedance speakers in parallel (creating an impedance below that
allowed by the Carver, or to having a loose strand of speaker wire
drift to where it wasn't wanted and create a momentary short circuit.

I'm not familiar with the Dynaco SAT-4 - I know of the PAS-4
(firebottle-based audio preamplifier/control center) and the PAT-4
(first-generation solid-state successor to the PAS-4). If those are
what you're referring to, I'd suggest that age may have caught up with
the device.

If a PAS-4 you might have a failed tube.

In either model, you could have an open/dirty/defective
balance-control pot, or volume-control pot, or switch. Operating the
input-selector, and tape-monitor switches a few times might restore
function if it's a dirty switch. A medium-term remedy for dirty
controls is a good squirt of a suitable control/contact cleaner into
the control (with power off!) while operating the switch or control
through its full range of motion. A longer-term cure may require
replacing the bad control.

Older Dynaco components can also suffer from dried-out electrolytic
capacitors... there are some in the signal path which can "go open"
and cut off the signal entirely.

--
Dave Platt > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Bob Landry]

Thanks for all the suggestions!

I will attempt to proceed in an orderly fashion with the suggestions made and
see what happens.

Bob

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[Bob Landry]

On Wed, 16 Sep 2009 19:06:23 -0600, Bob Landry > wrote:

>Thanks for all the suggestions!
>
>I will attempt to proceed in an orderly fashion with the suggestions made and
>see what happens.
>
>Bob
>
>Bob
>
>Just your basic flake, and official Old Fart!
>"The missing link between animals and the real human being is
>most likely ourselves."
>Konrad Lorenz

Experimental results:
1. Swapping the input cables seemed to result in a slightly better soundstage,
but this may have been due to my admittedly faulty hearing and wishful thinking.

2. Swapping the speaker cables brought about something very confusing, which was
a dead left (coming from the right output) channel. Playing with the mono/stereo
switched on the Dynaco made it obvious that there is an intermittent short in
these switches.

3. Restoring the speaker cables and pulling the PAT-4 and FM-5 out and twisting
all their cables seems to have resulted in a complete fix. Methinks I may have
to rout out the can of aerosol connector cleaner from the ex's garage and give a
few things a spray.

Later this week---- trying out the turntable for the first time!! Stay tuned.

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[Bob Landry]

On Wed, 16 Sep 2009 16:22:57 -0600, Bob Landry > wrote:

>Just deleted rec.audio.misc. since it seems to be populated by folks who can't
>seem to find *.*.politics. This groups seems to have folks who are actually
>interested in and knowledgeable about audio. I'm in the "interested" group, but
>not in the "knowledgeable" group.
>
>I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver power
>amp. I seem to have recently lost the right channel; moving the balance knob all
>the way to the right has no effect. I'm running the Carver into 2 Polk speakers,
>where I've used all 4 terminals on each, running two lines into each of the 4
>outputs on the Carver. I've checked and rechecked the connections, and they're
>all done the way the Polk instructions describe.
>
>Is there any way to tell whether the problem is with the Dynaco or the Carver
>without taking it to a shop? The drop off occurs with the CD player and the FM
>tuner, also a Dynaco, so I think it's safe to say that the problem is with the
>electronics and not the speakers, right?
>
>Any help for a new member and an electronic ignoramus greatly appreciated.
>
>Bob

$50 worth of Monster cable later, no hum, both channels up and running without
any loss.

But I'm still gonna clean the terminal outs on the Dynaco. And maybe, when I
have $250 to spare (HA!) I'll have it rebuilt and upgraded.

Thanks for all the suggestions and information!

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[Dave Platt]

In article >,
Bob Landry > wrote:

>$50 worth of Monster cable later, no hum, both channels up and running without
>any loss.
>
>But I'm still gonna clean the terminal outs on the Dynaco. And maybe, when I
>have $250 to spare (HA!) I'll have it rebuilt and upgraded.

Good going! It's always nice to resurrect a piece of older-but-still-
useful equipment.

I'd recommend getting a can of DeOxIt for the connector cleaning job.

--
Dave Platt > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Richard Crowley]

"Bob Landry" wrote ...
> Experimental results:
> 1. Swapping the input cables seemed to result in a slightly better
> soundstage,
> but this may have been due to my admittedly faulty hearing and wishful
> thinking.

Simply unplugging and re-plugging RCA connectors often will
clear up some symptoms caused by oxidation, dirt, etc. This
effect is frequently exploited by scam-artists selling premium
botique, snake-oil high-price cable.

[Richard Crowley]

"Bob Landry" wrote...
> $50 worth of Monster cable later, no hum, both channels up and running
> without
> any loss.

Simply unplugging and re-plugging RCA connectors often will
clear up some symptoms caused by oxidation, dirt, etc. This
effect is frequently exploited by scam-artists selling premium
botique, snake-oil high-price cable. Monster is among the
worst at swindling customers with overpriced cables. Their
other business practices are even more detestable. Avoid
Monster Cable.

[Bob Landry]

On Thu, 17 Sep 2009 14:04:46 -0700, "Richard Crowley" >
wrote:

>"Bob Landry" wrote...
>> $50 worth of Monster cable later, no hum, both channels up and running
>> without
>> any loss.
>
>Simply unplugging and re-plugging RCA connectors often will
>clear up some symptoms caused by oxidation, dirt, etc. This
>effect is frequently exploited by scam-artists selling premium
>botique, snake-oil high-price cable. Monster is among the
>worst at swindling customers with overpriced cables. Their
>other business practices are even more detestable. Avoid
>Monster Cable.
>

Since Monster was all that was available locally beyond the ubiquitous
black-with-red and white, and I have no dog in this fight, I went with them and
they solved the problem.

Then, being the curious sort, I did a search for audio cables and found the
Stealth site. Now that my blood pressure and breathing have returned to normal,
is there any possible reason for someone with mortal, human hearing to spend
thousands of dollars on CABLE!!??

There MUST be alternatives to this ethereal realm of wire and insulation, and
I'd be glad to know about it/them for future referrence.

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[Dave Platt]

In article >,
Bob Landry > wrote:

>Since Monster was all that was available locally beyond the ubiquitous
>black-with-red and white, and I have no dog in this fight, I went with them and
>they solved the problem.
>
>Then, being the curious sort, I did a search for audio cables and found the
>Stealth site. Now that my blood pressure and breathing have returned to normal,
>is there any possible reason for someone with mortal, human hearing to spend
>thousands of dollars on CABLE!!??

Excessive ego? Excessive credibility? An urgent need to get rid of
massive amounts of cash that's burning a hole in one's pocket?

>There MUST be alternatives to this ethereal realm of wire and insulation, and
>I'd be glad to know about it/them for future referrence.

Check out www.markertek.com, keyword search of "RCA cables", and then
click on "Stereo RCA cables" in the right column.

One example: their stock #18-5390 is a 6' stereo cable set,
low capacitance, shielded, gold-plated RCA connectors, for $10.49.

They have a TecNec-branded "premium" stereo cable, TN-2R2R-6, for
around $20.

They'll also sell you bulk wire (e.g. Belden) and individual RCA
connectors (numerous brands) if you want to make your own cables to
suit.

--
Dave Platt > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Richard Crowley]

Dave Platt wrote:
> Bob Landry wrote:
>> Since Monster was all that was available locally beyond the
>> ubiquitous black-with-red and white, and I have no dog in this
>> fight, I went with them and they solved the problem.

I'm a big fan of ubiquitous cables. I prefer them unless forced to
buy name-brand. But I'd rather use a rusty length of barbed-wire
than anything from Monster.

Or I make my own RCA cables with crimp-on connectors
and RG-59 off the reel.

[Mark Zacharias[_2_]]

"Richard Crowley" > wrote in message
...
> "Bob Landry" wrote ...
>> Just deleted rec.audio.misc. since it seems to be populated by folks who
>> can't
>> seem to find *.*.politics. This groups seems to have folks who are
>> actually
>> interested in and knowledgeable about audio. I'm in the "interested"
>> group, but
>> not in the "knowledgeable" group.
>>
>> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
>> power
>> amp. I seem to have recently lost the right channel; moving the balance
>> knob all
>> the way to the right has no effect. I'm running the Carver into 2 Polk
>> speakers,
>> where I've used all 4 terminals on each, running two lines into each of
>> the 4
>> outputs on the Carver. I've checked and rechecked the connections, and
>> they're
>> all done the way the Polk instructions describe.
>>
>> Is there any way to tell whether the problem is with the Dynaco or the
>> Carver
>> without taking it to a shop? The drop off occurs with the CD player and
>> the FM
>> tuner, also a Dynaco, so I think it's safe to say that the problem is
>> with the
>> electronics and not the speakers, right?
>>
>> Any help for a new member and an electronic ignoramus greatly
>> appreciated.
>
> The easiest way to identify whether the problem is in the preamp or
> in the power amp is to simply switch right/left between them. If the
> problem moves to the other side, then it is the preamp, if not, then
> it is the power amp.
>
> Do you have the technical info (schematic diagram, etc.) for either
> equipment?
>


I'm going to assume this is a PAT-4, even though I'm not all that familiar
with Dynaco - I have worked on a couple PAT-5's and I know there was a -4
model...

Anyway, the PAT-5's suffered from a number of bad electrolytic capacitors on
various boards. This often resulted in missing or low channels. Perhaps the
PAT-4 had similar issues.

Obviously, controls etc should be cleaned as with any equipment this
vintage.


Mark Z.

[Bob Landry]

On Fri, 18 Sep 2009 06:01:01 -0500, "Mark Zacharias"
> wrote:

>"Richard Crowley" > wrote in message
...
>> "Bob Landry" wrote ...
>>> Just deleted rec.audio.misc. since it seems to be populated by folks who
>>> can't
>>> seem to find *.*.politics. This groups seems to have folks who are
>>> actually
>>> interested in and knowledgeable about audio. I'm in the "interested"
>>> group, but
>>> not in the "knowledgeable" group.
>>>
>>> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
>>> power
>>> amp. I seem to have recently lost the right channel; moving the balance
>>> knob all
>>> the way to the right has no effect. I'm running the Carver into 2 Polk
>>> speakers,
>>> where I've used all 4 terminals on each, running two lines into each of
>>> the 4
>>> outputs on the Carver. I've checked and rechecked the connections, and
>>> they're
>>> all done the way the Polk instructions describe.
>>>
>>> Is there any way to tell whether the problem is with the Dynaco or the
>>> Carver
>>> without taking it to a shop? The drop off occurs with the CD player and
>>> the FM
>>> tuner, also a Dynaco, so I think it's safe to say that the problem is
>>> with the
>>> electronics and not the speakers, right?
>>>
>>> Any help for a new member and an electronic ignoramus greatly
>>> appreciated.
>>
>> The easiest way to identify whether the problem is in the preamp or
>> in the power amp is to simply switch right/left between them. If the
>> problem moves to the other side, then it is the preamp, if not, then
>> it is the power amp.
>>
>> Do you have the technical info (schematic diagram, etc.) for either
>> equipment?
>>
>
>
>I'm going to assume this is a PAT-4, even though I'm not all that familiar
>with Dynaco - I have worked on a couple PAT-5's and I know there was a -4
>model...
>
>Anyway, the PAT-5's suffered from a number of bad electrolytic capacitors on
>various boards. This often resulted in missing or low channels. Perhaps the
>PAT-4 had similar issues.
>
>Obviously, controls etc should be cleaned as with any equipment this
>vintage.
>
>
>Mark Z.

Thanks for the answer, Mark. Yes, this is a PAT-4, and I'm seriously considering
sending it off for a servicing and rebuild, although $250 for a $60 component
takes it out of the "bargain" class. Still, I bought it off ebay knowing (but
hoping not) that it would likely have issues.

As far as nuts and bolts are concerned, how does one go about cleaning controls?
Do they have to be removed from the amp, or does one just pull off the knobs and
spray away?

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz

[GregS[_3_]]

In article >, Bob Landry > wrote:
>On Fri, 18 Sep 2009 06:01:01 -0500, "Mark Zacharias"
> wrote:
>
>>"Richard Crowley" > wrote in message
...
>>> "Bob Landry" wrote ...
>>>> Just deleted rec.audio.misc. since it seems to be populated by folks who
>>>> can't
>>>> seem to find *.*.politics. This groups seems to have folks who are
>>>> actually
>>>> interested in and knowledgeable about audio. I'm in the "interested"
>>>> group, but
>>>> not in the "knowledgeable" group.
>>>>
>>>> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
>>>> power
>>>> amp. I seem to have recently lost the right channel; moving the balance
>>>> knob all
>>>> the way to the right has no effect. I'm running the Carver into 2 Polk
>>>> speakers,
>>>> where I've used all 4 terminals on each, running two lines into each of
>>>> the 4
>>>> outputs on the Carver. I've checked and rechecked the connections, and
>>>> they're
>>>> all done the way the Polk instructions describe.
>>>>
>>>> Is there any way to tell whether the problem is with the Dynaco or the
>>>> Carver
>>>> without taking it to a shop? The drop off occurs with the CD player and
>>>> the FM
>>>> tuner, also a Dynaco, so I think it's safe to say that the problem is
>>>> with the
>>>> electronics and not the speakers, right?
>>>>
>>>> Any help for a new member and an electronic ignoramus greatly
>>>> appreciated.
>>>
>>> The easiest way to identify whether the problem is in the preamp or
>>> in the power amp is to simply switch right/left between them. If the
>>> problem moves to the other side, then it is the preamp, if not, then
>>> it is the power amp.
>>>
>>> Do you have the technical info (schematic diagram, etc.) for either
>>> equipment?
>>>
>>
>>
>>I'm going to assume this is a PAT-4, even though I'm not all that familiar
>>with Dynaco - I have worked on a couple PAT-5's and I know there was a -4
>>model...
>>
>>Anyway, the PAT-5's suffered from a number of bad electrolytic capacitors on
>>various boards. This often resulted in missing or low channels. Perhaps the
>>PAT-4 had similar issues.
>>
>>Obviously, controls etc should be cleaned as with any equipment this
>>vintage.
>>
>>
>>Mark Z.
>
>Thanks for the answer, Mark. Yes, this is a PAT-4, and I'm seriously
> considering
>sending it off for a servicing and rebuild, although $250 for a $60 component
>takes it out of the "bargain" class. Still, I bought it off ebay knowing (but
>hoping not) that it would likely have issues.
>
>As far as nuts and bolts are concerned, how does one go about cleaning
> controls?
>Do they have to be removed from the amp, or does one just pull off the knobs
> and
>spray away?

You usually never go in from the front, but sometimes thats necessary due to
restrictions.

Usual step, closly examine from the rear. Most items have openings.
The spray would go in there. After application, works the controls.

On your outside connections, RCA's etc, water is a good first choice
to help remove water soluable films and green oxide.. Also some cleaner like
Fantastic can be applied with a rag. On really bad items
I would try TarnX, or worst case Scotch Bright. Then lubricate with something like
Caig Fader Lube or Deoxit Gold, or CRC 2-26

For the controls you can use plain alcohol to get basic cleaning,
or most use Deoxit then work the controls. After that apply
Caig Fader Lube.

greg

[Bob Landry]

On Fri, 18 Sep 2009 15:55:53 GMT, (GregS) wrote:

>In article >, Bob Landry > wrote:
>>On Fri, 18 Sep 2009 06:01:01 -0500, "Mark Zacharias"
> wrote:
>>
>>>"Richard Crowley" > wrote in message
...
>>>> "Bob Landry" wrote ...
>>>>> Just deleted rec.audio.misc. since it seems to be populated by folks who
>>>>> can't
>>>>> seem to find *.*.politics. This groups seems to have folks who are
>>>>> actually
>>>>> interested in and knowledgeable about audio. I'm in the "interested"
>>>>> group, but
>>>>> not in the "knowledgeable" group.
>>>>>
>>>>> I have a Dynaco SAT-4 that I bought used off eBay, along with a Carver
>>>>> power
>>>>> amp. I seem to have recently lost the right channel; moving the balance
>>>>> knob all
>>>>> the way to the right has no effect. I'm running the Carver into 2 Polk
>>>>> speakers,
>>>>> where I've used all 4 terminals on each, running two lines into each of
>>>>> the 4
>>>>> outputs on the Carver. I've checked and rechecked the connections, and
>>>>> they're
>>>>> all done the way the Polk instructions describe.
>>>>>
>>>>> Is there any way to tell whether the problem is with the Dynaco or the
>>>>> Carver
>>>>> without taking it to a shop? The drop off occurs with the CD player and
>>>>> the FM
>>>>> tuner, also a Dynaco, so I think it's safe to say that the problem is
>>>>> with the
>>>>> electronics and not the speakers, right?
>>>>>
>>>>> Any help for a new member and an electronic ignoramus greatly
>>>>> appreciated.
>>>>
>>>> The easiest way to identify whether the problem is in the preamp or
>>>> in the power amp is to simply switch right/left between them. If the
>>>> problem moves to the other side, then it is the preamp, if not, then
>>>> it is the power amp.
>>>>
>>>> Do you have the technical info (schematic diagram, etc.) for either
>>>> equipment?
>>>>
>>>
>>>
>>>I'm going to assume this is a PAT-4, even though I'm not all that familiar
>>>with Dynaco - I have worked on a couple PAT-5's and I know there was a -4
>>>model...
>>>
>>>Anyway, the PAT-5's suffered from a number of bad electrolytic capacitors on
>>>various boards. This often resulted in missing or low channels. Perhaps the
>>>PAT-4 had similar issues.
>>>
>>>Obviously, controls etc should be cleaned as with any equipment this
>>>vintage.
>>>
>>>
>>>Mark Z.
>>
>>Thanks for the answer, Mark. Yes, this is a PAT-4, and I'm seriously
>> considering
>>sending it off for a servicing and rebuild, although $250 for a $60 component
>>takes it out of the "bargain" class. Still, I bought it off ebay knowing (but
>>hoping not) that it would likely have issues.
>>
>>As far as nuts and bolts are concerned, how does one go about cleaning
>> controls?
>>Do they have to be removed from the amp, or does one just pull off the knobs
>> and
>>spray away?
>
>You usually never go in from the front, but sometimes thats necessary due to
>restrictions.
>
>Usual step, closly examine from the rear. Most items have openings.
>The spray would go in there. After application, works the controls.
>
>On your outside connections, RCA's etc, water is a good first choice
>to help remove water soluable films and green oxide.. Also some cleaner like
>Fantastic can be applied with a rag. On really bad items
>I would try TarnX, or worst case Scotch Bright. Then lubricate with something like
>Caig Fader Lube or Deoxit Gold, or CRC 2-26
>
>For the controls you can use plain alcohol to get basic cleaning,
>or most use Deoxit then work the controls. After that apply
>Caig Fader Lube.
>
>greg


Thanks, Greg. That was just what I was looking for. This group has been great
for information and patience with a rank electronic amateur!

Bob

Just your basic flake, and official Old Fart!
"The missing link between animals and the real human being is
most likely ourselves."
Konrad Lorenz