AB165 circuit that had been previously modified to use EL34s. Long ago, another tech had removed the bias balance control and performed some strange but minor circuit mods.
I undid most of the previous modifications, converted the weird AB165 feedback circuit to the AA864 specs, and modified the normal channel tone stack for a better guitar tone. I also paralleled the two triodes in the channel mixer stage, since there was an extra triode sitting there unused. The amp also needed some general maintenance and minor repair work.
