Tubes Asylum

Questions about tubes and gear that glows.

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RE: Importance of Phase Splitter/Driver Balance?

Posted by Palustris on May 20, 2009 at 10:16:24:
I don't have the schematic for any cj amps handy, but generally I believe the cj amps use a long tailed pair to affect the phase splitting while still offering some gain to the stage. The second tube that is driven by its cathode would have a variable resistor in the plate circuit so that the out of phase voltages (not the currents) match in level. So, yes, you would have to perform this balance operation as the tubes age or if they are changed.