On my 1971 Bandmaster Reverb, while retro-engineering the board to blackface specs (Vibroclone) I rewired the bias pot to AB763 specs per the Hoffman Amps website. I replaced the scratchy volume pot with a new CTS 1M audio taper pot. I installed a 120pf silver mica cap on the bright switch. I installed a 250pf silver mica cap in the tone stack (I only use the vibrato channel). The output is very low compared to normal and produces a very buzzy distortion when the volume is on 10. Ive checked and rechecked my work against the schematic and its correct. Upon visual inspection, there are no burned components, no arcing in the preamp tube sockets, and I swapped out the rectifier tube with no effect. Where should I go from here?