replacement transistors for a Kenwood KA 6004

M

Mac Lessig

Active Member
I have a Kenwood 6004 that was bought for parts sometime back. I did power it up and it worked although it took the relay longer than usual click in. The tuner and both Aux on the selector worked but the phono and the mike were very noisy and made popping sounds.
I figured I'd just keep it for parts. Two of the output transistors did come in handy as I had to replace two on the right channel on mine. However I've thought about repairing the parts amp. In looking for replacement transistors, the Sankan TO-3 2SC1402 and the TO-3 2SA744 as to replacements from mouser they are unavailable. I found several on ebay that are the TO-3 2SA744A and a TO-3 2SC1402A. However the old ones have 22R after the part numbers and the ones I'm looking at have 220 after the part numbers and what about the A after the part number?
I downloaded the schematic and the service manual. The service manual has a very good trouble shooting section (good for me) and a good section on componet values. what I need to know is will the replacement parts I'm looking at work with out issue after installed and the bias set as it needs to be. There is more to do as to the noise in the phono and mike section, so while I'm in there lets fix every thing and keep the amp for a standby just in case.
 
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Don't buy parts from E-bay, most are counterfeit. Just use MJ21193G and MJ21194G. They are readily available from Digikey and exceed the specs of the originals.
 
So you have two? That’s nice. I enjoy mine a lot. When I bought it it was very noisy,with lots of variable transistor noise. The transistors for the high and low pass filters were the worst. They are 50 volt transistors being operated at 45 volts. This has to be hard compared to the other transistors that are seeing only 35 volts. I ended up swapping out all the small signal transistors in the preamp section. It’s very quiet now. The amplifier section has always been dead quiet.

One of the things I like about isn’t that the amp and driver boards connect with computer card connections. Very easy to pull. The power supply, on the other hand is a bit of a pain.

Did you change the incandescent lights to LED? I did not, and I have never heard of one being done or a lamp burning out.
 
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