12-09-2016, 02:13 PM
These days (this was a modern amp) it seems 2% resistors come pretty much as standard. And in practice if I pull them off the bandolier I find they're often better matched even than that. So adding another 20% (a 2ohm fuse to the 10ohm bias sensor resistor) does make a significant difference. Of course, it could be fixed by adjusting the bias. But this is the only sensor of the bias that the poor customer has, and he isn't aware that whoever fiddled with the amp has changed it's calibration, so when he sets the reading to 450mV he still thinks he's doing the biasing properly (I suppose he might wonder why all the adjustment pots are now so very close to one end of their range though 
).
VB
).VB
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