volume pot on Kenwood KA-9100 integrated amp going bad

[larry]

hi,

after 30 years, the volume pot on my KA-9100 amp seems to be wearing
out.

i have read much on cleaning pots, (done that), and replacing pots.
my searching has found little on repairing pots.

'Secret Life of Pots' sailed right past the practicalities, (which i
need), and into the technicalites, (which i don't understand).

i was hoping someone had found a site with a faq or a howto on
repairing pots which they found useful.

any pointers or suggestions would be much appreciated.

thanx,
larry

 

[Bob Shuman]

Larry,

Just wanted to let you know I have the exact same Integrated DC amplifier
(Kenwood KA-9100) that I purchased new back in 1975! My unit still works
very well and I have not had any problems with my main amp volume control.
I am interested though in recommendations for cleaning the other switches
and potentiometers though since I do have some occasional cutting out on one
or both channels at low listening volumes. The problem goes away when I
flip a tape monitor, loudness, or tone defeat switch or play with the bass
or treble, so I know these are likely gummed up and dirty after nearly 30
years of use. BTW, I also have the matching KT-8300 AM/FM tuner which is
still working flawlessly!

Good luck and I'll be interested in hearing if you were able to clean this
successfully and what you used.

Bob

 

[Jerry G.]

There are some very good control cleaners out on the market. Most of the
time, the pots and switches can be cleaned using a good quality cleaner.

Visit any of the local professional electronics parts distributors in your
area, and you should be able to find these types of products.

If the pots and controls are not able to be cleaned, then they will have to
be replaced.

--

Jerry G.
==========================


Larry,

Just wanted to let you know I have the exact same Integrated DC amplifier
(Kenwood KA-9100) that I purchased new back in 1975! My unit still works
very well and I have not had any problems with my main amp volume control.
I am interested though in recommendations for cleaning the other switches
and potentiometers though since I do have some occasional cutting out on one
or both channels at low listening volumes. The problem goes away when I
flip a tape monitor, loudness, or tone defeat switch or play with the bass
or treble, so I know these are likely gummed up and dirty after nearly 30
years of use. BTW, I also have the matching KT-8300 AM/FM tuner which is
still working flawlessly!

Good luck and I'll be interested in hearing if you were able to clean this
successfully and what you used.

Bob

 

[larry]

bob,

good amp, isn't it.

i've already cleaned the pot with contact cleaner i got at Radio
Shack.

i do not think that is the problem. i think that it has worn down
where the wiper makes contact with the plate inside the pot. i hope
to find a faq or howto for dummies.

if necessary, i'll get a schematic and replace the pot. but, i'm
trying to keep it as original as possible.

thanx for the reply,
larry

 

[Asimov]

"larry" bravely wrote to "All" (30 Aug 04 05:05:26)
--- on the heady topic of "volume pot on Kenwood KA-9100 integrated amp going
bad"

la> From: [email protected] (larry)

la> hi,

la> after 30 years, the volume pot on my KA-9100 amp seems to be wearing
la> out.

la> i have read much on cleaning pots, (done that), and replacing pots.
la> my searching has found little on repairing pots.

la> 'Secret Life of Pots' sailed right past the practicalities, (which i
la> need), and into the technicalites, (which i don't understand).

la> i was hoping someone had found a site with a faq or a howto on
la> repairing pots which they found useful.

la> any pointers or suggestions would be much appreciated.

la> thanx,
la> larry

Larry, there might be nothing wrong with the pot. Sometimes a leaky
input coupling capacitor attached to the pot's wiper can cause
scratchy noises. Try replacing the cap with one manually selected for
low leakage and tack solder a high value resistor across the wiper to
ground. This value can be about 3 to 5 times the pot's rating and
should be enough to bypass any slight leakage away from the wiper.

A*s*i*m*o*v

.... Resistance Is Futile! (If < 1 ohm)

 

[good stuff]

hi,

after 30 years, the volume pot on my KA-9100 amp seems to be wearing
out.

i have read much on cleaning pots, (done that), and replacing pots.
my searching has found little on repairing pots.

'Secret Life of Pots' sailed right past the practicalities, (which i
need), and into the technicalites, (which i don't understand).

i was hoping someone had found a site with a faq or a howto on
repairing pots which they found useful.

any pointers or suggestions would be much appreciated.

thanx,
larry

Was that a high speed int amp or the one before them ? I seem to
recall the high speed amps had special "conductive plastic" vol pots
in them but don't quote me on that one.

doubt you can repair it unless just shooting it with cleaner will do
it for you, you might try replacing with a substitute using "short"
wires to match up the connections. Probably keep the old knob on the
outside.

I'd find a good quality substitute pot, but don't go nuts on expensive
spaciality ones.

Some of those old Kenwood integrated amps were outstanding. Esp the
ones with the bitchn dual power supplies and the huge toroidal
transformer. Cap city.

Anyone remember the LO7M component series ? ooooh that tuner was
great.

 

[good stuff]

I'd find a good quality substitute pot, but don't go nuts on expensive
spaciality ones.

LOL. Clicking the wrong spell checker selection.