Revox b285 repair

[steerpike2]

here is an interesting link - use google translate: shows an upgrade of a b285
I asked what benefit increasing the capacitance of the output to double 22,000 uf?
he did not know. but the wima to replace the rifa looks good?

The B250 was originally released with 2x22,000uF per channel, and that was later modified to 2x15,000uF ex factory. It is quite a stress on the transformer at power up - it has no soft-start - and the B250 transformers were failing more often than they should. But the B250 does have twice as many caps.

 

[sempai]

thanks bob - now i've discovered that some repairs were made - and entire section of ceramic and regular resitors were removed and only the ceramics were replaced with wrong values - brand -tru ohm 1250.

my amp board is 1.728.320-11 so i don't know what the values were - the service manual i have is for -00 and shows alterations 1-4.

where can i ask an expert?

thanks

In Toronto we are very lucky to have Roger Ginsley, North American Director of Service for Studer, NA nearby.

His company name is Tekx Electronics.

http://www.tekxelectronics.com/

You may find him helpful for parts and advice.

Willie Studer himself appointed Roger to his position of Director of Service.

(EDIT) No affiliation.
Art