CA-1010 Unable to adjust Class A bias, Normal OK

[Yamaha5000]

 

[Yamaha5000]

I think I am ready to put this back into the amp if you think it all looks good

One additional photo:

 

[mbz]

Should I replace all of these in that channel?

2SA745 - MJ21193
2SC1403 MJ21194

One of the 2SA745 measured faulty so yeah I'd replace the set of 4, ie, 2x2SA745 and their complement 2x2SC1403, I'd even measure Vbe and hfe and select closest match from available parts, I wouldn't go overboard on the matching, just select closest from parts at hand.

 

[mbz]

Solder bridge?

 

[Yamaha5000]

Bias is set correct for Normal and Class A
Meters adjusted as per spec
AC Output voltage is again off balance L: 26.1 R-28.0 I think that would a 3w difference (hardly noticeable?)
I have the audio generator (+2vpp) output cable connected to a Y to feed AUX R&L So input voltage should be equal. I guess I could try other inputs and see if the output balance would change.

 

[Yamaha5000]

Can these be used in this scenario also:



MUR1620CTRG
MUR1620CTG

 

[Yamaha5000]

What method and equipment to make these measurements?

 

[Yamaha5000]

With the kind assistance from many:

 

[mbz]

Did you check out the solder bridge in post #84

 

[Yamaha5000]

Did you check out the solder bridge in post #84

Yes