RB970BX Amplifier

[MeAN]

Hello everybody, first post here! :roll:
I am the proud owner of a couple of vintage Rotels, the RA1312 and RT1024, and I recently decided to taste a bit of the Rotel's more modern amplifiers' line.
My decision was for the RB970Bx (1994, 60Wx2) that I got rather cheap.
Now my question is: does anybody know the correct bias value for this ampli?
As I'm used to do when I buy used equipment, I checked both the DC-offset and the Power BJT's bias. It turned out that while the DC offset was quite good (2 and 4 mV), one channel had a 9mV bias, while the other only 1mV.
I read on a RB991 service manual that the bias for that model should be 7mv.
Do you think that this could be applicable to the RB970BX, too? Or - even better - has anybody the 970's service manual? ;x(

Thank you and pls forgive me for having started with a request :roll:
Carlo

[trats]

Carlo,

I've got an RB970BX mk2, with modded PSU section. The bias was around 8 mV each channel, and might be the same for the mk1 model. In case you haven't seen these before, the schematics for RA970 and RA971 are here,

http://www.eserviceinfo.com/downloadsm/22506/Rotel_RA-970BX.html

http://www.eserviceinfo.com/downloadsm/22508/Rotel_RA-971%20MkII.html

The amp section of my 970 is very similar to those integrated models. The offset of 2-4 mV seems v. good, but the bias on the other one seems off. Note the polarities of the DMM leads on the test pins in the technical manuals.

[MeAN]

Thank you trats for the very useful reply :T
You see, I'm used to deal with vintage equipment that usually uses a much higher bias (25-30mV).
At this point, I'd say that an 8 mV bias really seems the right choice to go for the rb970bx, too.

Thank you again,
Carlo

[deepakvali]

can u share whats e purpose of measuring bias?