Stereo receiver -- different channel volume levels

[zgraf]

I've got an older stereo receiver that is starting to die.
One channel is now much "louder" than the other--so I have to set the
balance control at about 80% / 20% to make the L and R channel levels
more uniform.
I think it sounds OK, but there does not seem to be as much "bass" on
the "degraded" channel--even when I try to match the "loudness"
levels.
Am I just imagining this? Or is power amplifier "deterioration"
sometimes accompanied by a loss of content in certain frequency bands?

[Bill Graham]

zgraf wrote:
> I've got an older stereo receiver that is starting to die.
> One channel is now much "louder" than the other--so I have to set the
> balance control at about 80% / 20% to make the L and R channel levels
> more uniform.
> I think it sounds OK, but there does not seem to be as much "bass" on
> the "degraded" channel--even when I try to match the "loudness"
> levels.
> Am I just imagining this? Or is power amplifier "deterioration"
> sometimes accompanied by a loss of content in certain frequency bands?

Swap all the left channel tubes with the right channel, and see if the
balance affliction also swaps channels. If it does, then swap them back one
at a time until you find the bad tube. If you don't have any tubes, then
your job is more complex....It involves lifting a wire in the signal path,
and swapping it with its mirror image wire, so the channels are swapped, and
seeing if the balance swaps also, and then going fromn there until you
isolate the problem.

[John Williamson]

zgraf wrote:
> I've got an older stereo receiver that is starting to die.
> One channel is now much "louder" than the other--so I have to set the
> balance control at about 80% / 20% to make the L and R channel levels
> more uniform.
> I think it sounds OK, but there does not seem to be as much "bass" on
> the "degraded" channel--even when I try to match the "loudness"
> levels.
> Am I just imagining this? Or is power amplifier "deterioration"
> sometimes accompanied by a loss of content in certain frequency bands?

Apart from the tube swapping exercise, it's possible that one or more
electrolytic capacitors are failing, so look for bulging cases or
leaking electrolyte typically showing as white powder round the terminals.

Other than that, compare voltages at various points between channels.

--
Tciao for Now!

John.

[Arny Krueger]

"zgraf" > wrote in message


> I've got an older stereo receiver that is starting to die.
> One channel is now much "louder" than the other--so I
> have to set the balance control at about 80% / 20% to
> make the L and R channel levels more uniform.

There are a number of failures that can cause this. There could be an
external problem that is causing it.

Your first diagnostic move is to swap first the input cables for the input
you use the most, swap L & R. Then do the same thing with the speaker
cables.

> I think it sounds OK, but there does not seem to be as
> much "bass" on the "degraded" channel--even when I try to
> match the "loudness" levels.

This could be due to a coupling capacitor loosing much of its capacitance.
Your perception of less loudness is partially based on there being less
bass.

> Am I just imagining this? Or is power amplifier
> "deterioration" sometimes accompanied by a loss of
> content in certain frequency bands?

Loss of bass in one channel more so than the other is a failure that I've
had in my own equipment, and diagnosed and repaired.

Thing is that you can get a good modern 100 wpc stereo receiver for less
than $100, and based on bench tests and listening tests, they can be really
very good. If you play LPs you might spend as much or more on a good add-on
phono preamp!

[Scott Dorsey]

In article >,
zgraf > wrote:
>I've got an older stereo receiver that is starting to die.
>One channel is now much "louder" than the other--so I have to set the
>balance control at about 80% / 20% to make the L and R channel levels
>more uniform.
>I think it sounds OK, but there does not seem to be as much "bass" on
>the "degraded" channel--even when I try to match the "loudness"
>levels.
>Am I just imagining this? Or is power amplifier "deterioration"
>sometimes accompanied by a loss of content in certain frequency bands?

You have coupling capacitors going bad. Since you don't mention anything
about what model it is or what technology it is, I can't make any particular
recommendation about what to do about it.

This is probably the most common failure mode on audio gear from the seventies
which used electrolytic capacitors for coupling all over the place.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[RD Jones]

On Dec 3, 9:41*am, (Scott Dorsey) wrote:

> This is probably the most common failure mode on audio gear from the seventies
> which used electrolytic capacitors for coupling all over the place.

.... especially between the output stage and the speaker.

[Arny Krueger]

"RD Jones" > wrote in message

> On Dec 3, 9:41 am, (Scott Dorsey) wrote:
>
>> This is probably the most common failure mode on audio
>> gear from the seventies which used electrolytic
>> capacitors for coupling all over the place.
>
> ... especially between the output stage and the speaker.

It has been my experience that the large electrolytics that were used in
early days to block DC between the output stage and the speakers were
generally pretty reliable.

It's the little ones in and around the line level buffers, tone controls,
etc. that seem to be most likely to open up. If anything, as a class they
might fail more because there are simply more of them.

[TimR]

On Dec 3, 7:48*am, "Arny Krueger" > wrote:

>
> Thing is that you can get a good modern 100 wpc stereo receiver for less
> than $100, and based on bench tests and listening tests, they can be really
> very good. If you play LPs you might spend as much or more on a good add-on
> phono preamp!

I have the same type of failure. Any recommendations on that modern
100 W stereo amp?

I have a number of CDs with different parts on different tracks,
designed as playalong duets. These require a balance control, and not
all modern receivers still have this slider.

[Arny Krueger]

"TimR" > wrote in message

> On Dec 3, 7:48 am, "Arny Krueger" >
> wrote:
>
>>
>> Thing is that you can get a good modern 100 wpc stereo
>> receiver for less than $100, and based on bench tests
>> and listening tests, they can be really very good. If
>> you play LPs you might spend as much or more on a good
>> add-on phono preamp!
>
> I have the same type of failure. Any recommendations on
> that modern 100 W stereo amp?

I listen a lot through a Sherwood RX 4105.

My "other" stereo receiver is a Sansa Clip+. Other than power output, size
and power, they perform pretty much the same. Well, the Clip also stores and
manages its music library.

> I have a number of CDs with different parts on different
> tracks, designed as playalong duets. These require a
> balance control, and not all modern receivers still have
> this slider.

The Sherwood RX 4105 has a "Balance" button on its front panel that
repurposes the volume control knob to be the balance control. This feature
is not on the remote control.