Kenwood Basic c2 balance adjustment pot

purenrg

New Member
I have a Kenwood basic c2 with a bad balance adjustment pot is there anyone here that may know where to pick one up, or someone that works on or rebuilds these pots?
 
Well, I have started my on rebuild on my balance pot for the C2, man are the contacts Small in these potentiometers. we'll, see how it goes?
 
Rebuild Update, project was a success, but it was truly nerve racking job, I would not want to do it again anytime soon, and anyone that has ever done one of these before knows exactly what I'm talking about.
The Japanese should have used epoxy on these parts and this problem would not had ever occurred in the first place, I used JB Weld and it will never come loose again.

It was like operating on a Genia Pig!!!. Lol. the PIG still lives
 
What did you do exactly? I'm picking up the same pre-amp tomorrow which has sound out of only one channel, googling shows this is a common flaw usually due to a bad balance adjustment pot, how did you go about rebuilding it?
 
huh, not had that problem at all.. Well leave it for now, there's nothing more irritating than writing a whole thing out to just then lose it, maybe when I get it I'll just hit you up over PM for your help, if you don't mind?
CHeers!
 
This is the procedure I took to rebuild the balance potentmeter, I recommend that you skip on the coffee before starting this endeavor.

First remove cover and face plate from chassis this will allow access to the balance pot circuit board, there are two small screws & a retaining nut that holds this pot to the chassis.

Next you will see two aluminum retaining pins, these pins must be removed to dissemble the pot. Too remove the pins you will need to remove the splayed end that looks like a slot for a flat bladed screwdriver, I used a Dremil tool for this part to grind the splayed ends off. ( Only take off as little as possible of the pins) now try and drive the pins out of the body of the pot.

With pins out and metal backing tab removed you will see a mounting fiberglas contact pad, that is soldered to the little circuit board, this pad will have a hole in the center, this will need to be removed to access the "c" clip.

Now remove the "c" clip from the pot stem, this will give you access to the plastic rotor that the stainless steel contacts or mounted on, the contacts need to be reattached using an epoxy I used JB Weld, there will be one of these contacts on each side of the plastic rotor.

After this has been done you will reassemble the pot in the reverse order,so take your time because these parts are very {SMALL} especially the "C" clip,and contact brushes, you don't wont to loose them!!!!

Good luck, and pat yourself on the back and drink your self a beer when done because you deserve it !!!!!:banana:
 
Is there a way to spray DeoxIt into the pot without taking it apart? I have a Basic C1 that needs to be worked through.
 
qpagoda, I tried to clean the contacts by doing that very thing, there is a very small hole that you can try and spray into, but it's a very... very small hole. More than likely the contacts have broke off the plastic rotor, if this has happened then this will not help.

I cant believe that these Japaneses engineers developed this part this way, they should have used a epoxy to attach these contact too the rotor assembly. and if you ever take one of these potentmeters apart and see how they did it, you will under stand how come these parts are failing :nono:
 
This is the procedure I took to rebuild the balance potentmeter, I recommend that you skip on the coffee before starting this endeavor.

First remove cover and face plate from chassis this will allow access to the balance pot circuit board, there are two small screws & a retaining nut that holds this pot to the chassis.

Next you will see two aluminum retaining pins, these pins must be removed to dissemble the pot. Too remove the pins you will need to remove the splayed end that looks like a slot for a flat bladed screwdriver, I used a Dremil tool for this part to grind the splayed ends off. ( Only take off as little as possible of the pins) now try and drive the pins out of the body of the pot.

With pins out and metal backing tab removed you will see a mounting fiberglas contact pad, that is soldered to the little circuit board, this pad will have a hole in the center, this will need to be removed to access the "c" clip.

Now remove the "c" clip from the pot stem, this will give you access to the plastic rotor that the stainless steel contacts or mounted on, the contacts need to be reattached using an epoxy I used JB Weld, there will be one of these contacts on each side of the plastic rotor.

After this has been done you will reassemble the pot in the reverse order,so take your time because these parts are very {SMALL} especially the "C" clip,and contact brushes, you don't wont to loose them!!!!

Good luck, and pat yourself on the back and drink your self a beer when done because you deserve it !!!!!:banana:

:thmbsp::tresbon:

Thanks so much for the excellent write up!!!! picking up this preamp this evening.

I will observe the correct order of libations too :D
 
Wow, this isn't easy, taking that pot apart was not fun. I have the c clip, it was already attached but I added epoxy anyway. There is only one of these c clips, it's on the front, on the back of the plastic rotor there is nothing.. I assume there should be something there?
 
Well, I'm going to bypass the pot, I couldn't fit it back together properly and I snapped one of the fiberglass circles. Really is a fiddly little thing. I don't know much about working with electronics, but I think I figured it out from this German page. Danke! :tresbon::tresbon::thmbsp::thmbsp::thmbsp::thmbsp:

These guys bypassed it, that would also be fine for me as balance control has no use to me

http://www.hifi-forum.de/viewthread-185-9804.html


uberbruckung-des-balance-regler-im-kenwood-basic-c2_255808.jpg


finale001255882.jpg


Kurzschluss= resistor
Widerstand= short circuit


They used 2 180kohm resistors.. I went back and forth as a lot of values were thrown out and poor google translation made it confusing, but then I looked at the color bands (Hey look at me, I'm learnin') they are in fact 180k ohm resistors with 1% tolerance. I don't know why they need resistors as I don't know much about electronics. I assume the short is there to bypass the balance control and the resistor is there to effectively remove the operation of the varying degrees of loudness which would be controlled by the dial? This is an assumption and probably incorrect. Is there a reason to add a resistor or would breaking the circuit by removing the solder connections be enough? I don't know, so I'll just follow what these guys did.

I have to desolder entirely the pot and remove it. Then I have to find somewhere that sells 180k ohm resistors.
 
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Radioshack rather unhelpfully doesn't sell 180k ohm resistors. But they do sell, 100k ohm, 47k ohm and 33k ohm. So I bought a pack of each as their value adds up to 180k ohm and it is my understanding that I can wire one of each together by twisting the end together and then soldering it. The wattage value of the resistors is 1/2 watt. I'm not sure what wattage I needed so I went with the highest ones I could buy since it doesn't matter if I have more but it matters if I have less.

Before I get round to doing this this evening, it would be really helpful if someone could chime in if I'm making some glaring schoolboy error.
Cheers.
 
Here's a shot of the guts

67674914.jpg


no real reason...

And this is the little bleeder that causes all the problems...

15993811.jpg
 
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Success!! I'm actually surprised.

Remove solder and pot
pot1m.jpg

pot2.jpg


Put resistors in series, by wrapping wire then covering joins in solder. I trimmed a bit off the wire on both ends on the middle resistor to make this easier. It doesn't matter which order or which way around you put the resistors.

resistor1.jpeg


most nerve wracking part, short the two joins and attach resistors without buggering up separation of each other

resistor.jpg


Here's a thought, just get an actual 180k ohm resistor off the web, having three gives you little room to fit stuff back in.

Hope this helps anyone with similar problems, two solutions, repair pot, failing that bypass.

Now I'm going to have that beer, connect up my record player and see what all the fuss is about with this c2 phono stage.

:thmbsp::music::beer::beerchug:
 
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Biig panic moment. connected everything up, huge hum out of both speakers, looked at the ground wire fropm TT it was starting to come apart. Good thing I had my soldering stuff out, soldered it back together. plug it all back in. huge hum still. More panic... Figured out my rca cable was screwed up, all is well, now I'm tired.
 
Everything is working great except the phono section, when I plug it ion there's a huge hum, I was getting it off every input till I switched out my rca cable, but it's really bad on the phono still, dead silent on everything else, do you think the phono section is screwed or my ground wire is.

OTOH I see why people go for separates, playing music from my phone with its crappy DAC is a noticeable improvement even against my Denons good DAC
 
This is a real good preamp, I hope I can fix my phono problems, but this one is a keeper, everything sounds better through this and I'm talking 256kbps mp3 on a crappy phone DAC vs FLAC on a great Burr Brown DAC. Even if I can't figure out the phono section. This is staying on my deck, I only paid $35 for it (it was broken)

Very happy despite problems. :)
 
Well after unplugging everything, switching things around grounding the ground to my receiver, grounding it back to the pre-amp.... I wiggled the ground wire and the hum went away. LOL

Anyway, I wanted to make a final post just to say how great this pre-amp is!!

The phono stage is much better than the one on my Denon 3803, the highs and mids are clearer, but what is best is that the bass is so well defined now. Listening to Flea on the new Atoms for Peace. Superb.

If you get a chance to pick one of these up for nothing because "one channel is out". Do it, while the fix isn't easy, you can do it if I can do it and this preamp really is a good one.
 
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