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- May 14, 2014
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- No such things as bad days, just bad moments
The Sony STR-6045 I just acquired (and posted about) has unequal DC offset. There is 13mv on one side and 74mv on the other. Bias current was 12.5mv on both channels but the service manual said 25mv. I adjusted accordingly but DC offset seemed unaffected.
I was under the impression that DC offset was altered by adjusting bias current.
In any case, is the offset disparity cause for concern? The opinions I've read seem to say 74mv is not great but not atrocious. The receiver performed OK with unaltered bias but I've not spent time with it since kicking it up to 25mv. If sound is good and it does not start off throwing off heat, would anyone be bothered about the offset difference?
Despite that I did not do well trying to refurbish a Kenwood integrated, I don't think I'd be against changing the differential transistor pairs. Provided that is I can figure out which new ones would work, I always have trouble with that. And, that critical matching is not essential.
I was under the impression that DC offset was altered by adjusting bias current.
In any case, is the offset disparity cause for concern? The opinions I've read seem to say 74mv is not great but not atrocious. The receiver performed OK with unaltered bias but I've not spent time with it since kicking it up to 25mv. If sound is good and it does not start off throwing off heat, would anyone be bothered about the offset difference?
Despite that I did not do well trying to refurbish a Kenwood integrated, I don't think I'd be against changing the differential transistor pairs. Provided that is I can figure out which new ones would work, I always have trouble with that. And, that critical matching is not essential.