One channel AB763 No Trem (Circuit issue)

[ToneJunkie]

I found a mistake in a old amp I built and I have a question about the schematic I used.  This amp suffers from excessive gain and excessive bass.  I will post pics later but I was wondering if someone could help me with a schematic question.  In between the preamp and the coupling cap of the phase inverter I'm not sure how the circuit should be here.  Any help appreciated.

[glass54]

Hi ToneJunkie,
I just used Hoffman's One Channel AB763 schematic and Turret board. Works well, in fact excellent. 
In your case just remove the Tremolo section.
https://el34world.com/Hoffman/files/Hoffman_AB763_1.pdf
Kind regards
Mirek

[sluckey]

To tame the gain you need to add a 47K resistor to ground at the point indicated in red. (It's R30 on the schematic linked by glass54). Also remove the 220K mixing resistor.

To tame the bass replace the four 22µF preamp cathode caps with 2.2µF or 4.7µF caps.

[pdf64]

I can't see why it does so (turnover frequency is way below bottom E), but the 47k ' pretend trem intensity control' resistor seems to calm the bottom end / thin the tone, a bit. So messing with the low end may not be necessary.

[Greg]

Just check (to be sure) the negative feedback dividing network to see if there is continuity... (If) the feedback loop is open in those type of amps, it might exactly sound like you have lots of gain and excessive bass...

[ToneJunkie]

Thanks guys!  So I have built several of these some with reverb and some without.  Why do we keep the mixing resistor when we do this circuit without reverb but remove the mixing resistor when we do this amp with reverb?