Toshiba Sa-775 Bias / DC Offset

[KrZ8]

Hello,

I have a Toshiba Sa-775 75WPC with some dc on its outputs. There are several VRs on the power amp board but I cannot seem to find instructions on which ones to adjust, nor on where to check for bias. Does anybody knows ?

Thanks,

Alex

 

[MAXZ28]

Yep.

Send me your email in a PM. I have the scanned SM right here.

 

[KrZ8]

Thanks Darren!

It appears that this amp only has bias adjustments. Here is the relevant information for future reference and search purposes:

IDLING ADJUSTMENT

1. Connect a tester to test points No. 1 an 2, 3 and 4. (They are above the transistors)
2. Adjust the semi-fixed resistors (R535 and R536) so that the tester indicates 8.8mv to 22mv

Alex

 

[ecluser]

Alex, what is the magnitude of your DC offset?

 

[KrZ8]

It's only in the 30mv range, so there is really nothing to write home about just yet. It still sounds good. I just figured that I might as well adjust it while it is opened on the workbench.

I guess I'll just adjust the bias, clean the controls and put the cover back on for another couple years before changing componants :thmbsp:

thanks for your help!

Alex