Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Steve S. on February 26, 2019, 01:52:32 pm

Title: early 70s twin reverb
Post by: Steve S. on February 26, 2019, 01:52:32 pm

I have an early 70s twin reverb with push pull master volume on the bench. I found a resistor that is darkened by heat to the point  that I can only make out the first blue band and not the other two.  This is on the power tube balance pot side of the .1 blocking cap for the PI tube (pin 6).  I'd like to check and maybe replace the resistor but I can't find a specific schematic and or layout for this amp to show me the ohm rating. Can anyone send a link to this or at least tell me what ohm this resistor should be.
Thank You, Steve

Title: Re: early 70s twin reverb
Post by: sluckey on February 26, 2019, 02:01:27 pm

68K. There should be another one tied to the other side of the balance pot. The schematic is in Hoffman's schematic library. Follow the link at the bottom of this page.

Title: Re: early 70s twin reverb
Post by: Steve S. on February 26, 2019, 02:20:17 pm

Thanks for the quick reply. I found the schematic this time.
Steve