Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Underwood on January 21, 2014, 06:11:25 pm

Title: '68 SUper reverb anomalies
Post by: Underwood on January 21, 2014, 06:11:25 pm
 :w2: I've been working on a '68 super reverb and have noticed a couple of strange things. First is that on the vibrato channel, there is not any or barely any volume when the treble is down. Second, I plugged into the normal channel and was still able to use the reverb. Before I go through the whole schematic I was wondering if this rang a bell for anybody.  THANKS!!
Title: Re: '68 SUper reverb anomalies
Post by: sluckey on January 21, 2014, 06:50:58 pm
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First is that on the vibrato channel, there is not any or barely any volume when the treble is down.
Could be normal. Were the mid and bass also turned down low? All the Fender Treble/Middle/Bass (TMB) tone stacks will totally kill the signal if all three knobs are set to zero.

Quote
Second, I plugged into the normal channel and was still able to use the reverb.
It's been modified. There's a very simple mod to enable reverb on both channels. See attached...
Title: Re: '68 SUper reverb anomalies
Post by: Underwood on January 21, 2014, 07:13:44 pm
Thanks. I will check out that reverb mod and see if that is what was done. As for the other thing, the bass was on zero, but the middle was not.