re:
"The green boards inside these lollipop mics work OK after adding a filter cap (blue electrolytic in photos), but output polarity is wrong for studio use, requiring trace cuts and jumpers to swap pins 2 & 3. These boards don’t have the phase inverter problem.
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I got to wondering if these green PCBs from 10 years ago DO have the "inverted inverter" transistor after looking at the frequency response charts. Turns out they do. The PNP transistor used works better reverse biased than most, so bass rolloff isn't as severe as the black boards. There is a little more room around the transistor in question, so it is possible to leave the base soldered to the board, unsolder the emitter and collector, stand the transistor with collector upward, swing the emitter over and tack it to the proper pad, then run a wire from the collector to the proper part of the circuit. Looks something like this:
There are a couple of other mistakes in this PCB, so this may be where the swapped E & C connections in Asian pencil mic boards came in.
