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Yamaha PC2002M restoration

Lucky your DC offset is good. I have to figure out how to disable the DC Servo and then to adjust DC offset to zero. From what I have read here, the PCB's become conductive, especially in high hour units like mine. I think mine were on 24/7 for 20 years or more before being retired.
 
amr2 said:
Really?:eek:

I think that you can fix or bypass the DC servo. Let me see the schematic and I will tell you something.
Click to expand...

I was told when I bought the amps (broken), they were from Disneyland. I managed to fix one with driver boards from a beat up PC2002M and sold it to someone who had bought amps from Disneyland and recognized the plastic ID plate that is attached to the faceplate. He said the park ran tons of them. This is hearsay so I can't directly confirm.

Thanks for looking at the schemo for me. I am illiterate in these matters.
 
All mechanical parts are disassembled, I will begin to restore them in the upcoming weeks. The good news is that all the electronic parts are original, and it seems it was never been repaired. And the boards are not "toasted" :D. Anyway I think I'm going to recap it.

IMG_1577.JPG
 
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rottalpha said:
This is an amazing piece of equipment.
It is amazing what you could get for a few hundred $$,€€
Click to expand...

Yes, I think so. :thumbsup:

For anyone interested, I have attached the BOM I have just ordered.
Edited: UCC E36D101LPN223TDB7M / EPCOS B41456B9229M / VISHAY MAL210119223E3 can be used as replacement for main filter caps
 

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Why did you select Nichicon HE caps ?
NOT to start a cap debate (we had enough of them), just my curiosity.
 
Oilmaster said:
Why did you select Nichicon HE caps ?
NOT to start a cap debate (we had enough of them), just my curiosity.
Click to expand...

They are low ESR, high temp, high ripple and I think that they are a good option for power supplies and filtering, outside the audio path. I decided to get the HE parts where available and PW/PM for the others. I also like Panasonic FM/FC series.
 
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Nichicon KZ for power supplies, and 100V versions for signal coupling in case electrolytics are the only option (i.e. >1uF)
Nichicon FG for the rest.
Nichicon KG for the large PSU caps

Alternatively Elna RFS (SilmicII) for signal coupling, tone control stages and RIAA stages.
When many electrolytics are used for signal coupling (like in integrated amps/receivers with tone control stages), I tend to mix Elna RFS and Nichicon KZ to ..... :)

Panasonic FM/FC are often quoted as good caps for audio gear; I simply never used them.
Perhaps I should one day :)
 
I have also used KZ/FG/KG several times, with great results. But I think that non "boutique caps" are also a great choice.

IMHO, more or less the HE series would be the equivalent to the Panasonic FM, and PW the equivalent to Panasonic FC series.
 
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amr2 said:
IMHO, more or less the HE series would be the equivalent to the Panasonic FM, and PW the equivalent to Panasonic FC series.
Click to expand...

Because I will soon have to pass a massive order at Mouser anyway, I will order some HE / FC / FM series for ESR, Z and phase shift comparison with FG and KZ series (all the same capacitance and voltage rating of course). let's see how they compare.
 
Oilmaster said:
Because I will soon have to pass a massive order at Mouser anyway, I will order some HE / FC / FM series for ESR, Z and phase shift comparison with FG and KZ series (all the same capacitance and voltage rating of course). let's see how they compare.
Click to expand...

Very interesting, please keep us informed! My bet is for Pana FM :naughty:
 
There are two VD-1212 varistors on the power supply board, and two MV-12 on the driver board. I think it would be a good idea to replace them with a series pair of 1N4148 diodes..what do you think?
 
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