Lloyd wrote:I found this too when replacing the idle current pots in my B&O Beomaster 5000, it had been shutting down after a few minutes use, and kicking out some serious heat from the heatsink at the back. I only replaced them because I couldn't set the required 11mV across 2 testpoints, and because some post on another forum said the pots are crap, they were both labelled 100 ohms, I removed them ready to fit the replacements, and measured the wiper position, so I could get the new one set to somewhere near where it needed to be. When I stuck the meter on it read 155 ohms! And it changed depending on temperature, no wonder the poor amp was shutting down! I changed all the electrolytic caps whilst I had it in bits too. Amp runs nice and cool now, and sounds good too
Crackle wrote:Is it all that critical in a volume circuit to be 50% out in value?
If a pot was controlling an op amp as the FB resistor and was 50% lower then the gain is lower as a result.
Dr Wobble wrote:... Guess it depends how the pot is controlling the signal. If, as is the case on this mixer, the pot attenuates the signal before it reaches the pre amp stage then a pot that is 50% higher in value must cut the signal by that much ...
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