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The Fisher SA-16 I've been working on has a pair of 50k pots to adjust phase inverter balance. The Fisher factory schematic says "These adjustments should not be attempted unless you have a harmonic distortion analyzer and audio generator; or intermodulation analyzer."
Since I don't have the required equipment I left them alone. I did have to replace the two 12AX7s though since the originals were both bad. I'm pretty sure this amp was never touched until I started rebuilding it.
The cathodes of the phase inverter sections have a 56k resistor to the 50k pot. When I measure from cathode to ground I get 62v and 65.5v. One channel drops all but .66v across the resistor. The other channel drops 44.3v across the resistor and 21.2v across the pot.
Should I be concerned about these differences or should I just leave it alone? Is there any other way to adjust the balance without the equipment mentioned above? I don't have a scope either, just a DMM.
Follow Ups:
This may help:
http://audiokarma.org/forums/index.php?threads/quick-and-easy-400-phase-inverter-adjust.559415/
I think an oscilloscope and a signal generator, even a single frequency, like 1k hz would be a better substitute for the equipment mentioned.
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