identifying russian made capacitor

[mastermikie]

I own a Russian made marshall guitar amp clone.
A Sovtek mig 100 u.
I found a schematic for the 100 h and have verified they are very similar in build.
However during a bias adjustment I found it almost impossible to get it set at the 40ma it supposed to be. the control pot is at its minimum and still runs at 41ma.
this in itself is not a big issue. although I believe the capacitors in this circuit are likely out of tolerance.

The schematic for the h model shows 50uf 100v caps. but looking at the actual caps (which are Russian marked) I believe these to be 1000uf caps.

Any assistance reading or decoding these would be very helpful. I have already been to this site Capacitors options Directories Amateur Electronics
and still am a bit confused.
I will include the schematic for the H model as well as a pic of the actual cap.

thanks in advance.

 

[Tiido]

That's the 25V 1000µF cap seen in bottom of the schematic.

 

[mastermikie]

ok thank you. they were located directly next to the bias adjustment so without removing the board and following traces I made the assumption they were the bias caps.
but this makes more sense. I will go back and look at the other 2 that were close by and get their ratings.

 

[mastermikie]

btw... are the spacers supposed to be that color or are these suspect?

 

[Ddd_rus]

The spacers are ok, it's just another type of fabric/resin composite, not a glass/epoxy one so the color is fine.
The caps are 1000h@85°C standard elcos, nothing special. Any audio series caps should be better than these.

 

[Enzo]

The filter caps for the bias supply are not changing its voltage.

I don't know how you got 40ma as a goal, but if you can set the amp up for 41ma, that is close enough, I'd consider it adjusted.

If you need to increase the bias voltage a few points, reduce the value of the 15k resistor in the bias supply.