Vintage Receiver Problems

[Mark Baglia]

I have a pair of vintage receivers, both of which seem to be having the same
problem. Both receivers work wonderfully, but only do so after playing with
the volume control for a while. Generally, changing the volume results in
various forms of distortion and most notable, the elimination of nearly all
mid-bass and bass and eavy distortion to the vocal range. Has anyone ever
had similar problems and might know the cause or a way to fix it? Just fyi,
the receivers are a Marantz MR255 and an Technics sa-300. Thanks for your
help.
-Mark

[Mark D. Zacharias]

Sounds as if the controls need cleaning. Very common problem on older
pieces. There is a technique or two to learn, but the basic process is to
use an aerosol cleaner / lubricant designed for the purpose (Caig DeOxit or
similar), spray a bit into the control where the relevant contact surfaces
are, and work the control back and forth, then repeat.
Variations include packing tissue around the control to catch runoff,
tilting the piece to allow gravity to help, using an air compressor before
and after, etc.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Mark Baglia" > wrote in message
...
> I have a pair of vintage receivers, both of which seem to be having the
same
> problem. Both receivers work wonderfully, but only do so after playing
with
> the volume control for a while. Generally, changing the volume results in
> various forms of distortion and most notable, the elimination of nearly
all
> mid-bass and bass and eavy distortion to the vocal range. Has anyone ever
> had similar problems and might know the cause or a way to fix it? Just
fyi,
> the receivers are a Marantz MR255 and an Technics sa-300. Thanks for your
> help.
> -Mark
>
>

[unitron]

"Mark D. Zacharias" > wrote in message >...
> Sounds as if the controls need cleaning. Very common problem on older
> pieces. There is a technique or two to learn, but the basic process is to
> use an aerosol cleaner / lubricant designed for the purpose (Caig DeOxit or
> similar), spray a bit into the control where the relevant contact surfaces
> are, and work the control back and forth, then repeat.
> Variations include packing tissue around the control to catch runoff,
> tilting the piece to allow gravity to help, using an air compressor before
> and after, etc.
>
> Mark Z.
>
> --
> Please reply only to Group. I regret this is necessary. Viruses and spam
> have rendered my regular e-mail address useless.
>
>
> "Mark Baglia" > wrote in message
> ...
> > I have a pair of vintage receivers, both of which seem to be having the
> same
> > problem. Both receivers work wonderfully, but only do so after playing
> with
> > the volume control for a while. Generally, changing the volume results in
> > various forms of distortion and most notable, the elimination of nearly
> all
> > mid-bass and bass and eavy distortion to the vocal range. Has anyone ever
> > had similar problems and might know the cause or a way to fix it? Just
> fyi,
> > the receivers are a Marantz MR255 and an Technics sa-300. Thanks for your
> > help.
> > -Mark
> >
> >

The stuff Mark is talking about is known to any TV repair shop as
tuner cleaner, maybe you can find a shop that'll be willing to squirt
all your controls for you fairly cheap. If you do it yourself (you
can get a can at Radio Shack, although you'll pay about twice what a
TV tech does when he orders the same thing under a different name from
a parts house), use the little plasic tube that comes with it and
don't hold the button down for more than a half second, just a quick
burst, then there won't be much runoff to worry about although the
only time you need to wipe it up is if you use it like a fire hose.
Unplug your gear and let it cool down to room temp to avoid thermal
shock, this stuff comes out of the can fairly cold (and of course you
need to unplug before taking the cover off anyway). Good luck.
e-mail me with questions.