I sent my Super Reverb to a guy in N Carolina last year in August, and he had it for over 6 months and I had to tell him to just get it back to working condition and send it to me.
I got it back and the distortion mod he did sounded good but my cleans were all screwed up and the vibrato didn't work any more. I found a amp tech that lived 45 miles away. Come to find out that Sean had wired it all to the old black face specs and most of it was wrong. My amp was a Ultra Linear model so he a the plate voltage all wrong and the transformer was tapped incorrectly. here is a list.
It'd be easier to make a list of the things I didn't un-do...
Tremolo switch, new 8-pin octal tube socket, one 20 mfd / 500 Volt filter cap.
But here's a run-down of the things I either put back the way they were, or reworked/rewired/or replaced:
-Replaced original power cord and repaired the end. (it is longer and more rugged)
-Removed Copper-Cap (half-wave) rectifier module and replaced with ultra-fast recovery expatial diodes (full-wave)
-Removed Choke -- replaced original voltage divider resistors.
-redesigned (and relocated) bias adjustment circuitry to work with higher voltages now present.
-Replaced 100 mfd/350 Volt capacitors with original 220/285's (They are fine, and best if larger value on the UL)
-Replaced 2 other bad Mallory 20/500 caps with Sprague TVA type. (they were bad)
-Properly wired voltage dropping resistors under capacitor cover. (they were reversed)
-Replaced 'presence' resistor under tone stack.
-Adjusted feedback resistor for minimal global negative feedback. (820 ohms is way too much)
-Fixed improperly wired tremolo tube socket.
-Entirely rewired LondonPower FPM kit to eliminate oscillations. (reorganized and used smaller sheilded wire)
-Fixed reversed values of bass and mid caps on channel 2
-Rewired output jacks to accomodate multi-tap secondary of output transformer and present proper impedances.
-Replaced line-out jack (it does not limit power.)
-Replaced weak 6L6 tubes
New work:
-Replaced all film capacitors with Sprague Orange-Drops
-Built and installed control board for LondonPower ERK (channel-switch) kit.
-Cleaned all tone controls on channel 2.
-rerouted wires to tremolo tube to eliminate 'thump' when tremolo on.
----Still working on why tremolo intensity is too low
I got it back and the distortion mod he did sounded good but my cleans were all screwed up and the vibrato didn't work any more. I found a amp tech that lived 45 miles away. Come to find out that Sean had wired it all to the old black face specs and most of it was wrong. My amp was a Ultra Linear model so he a the plate voltage all wrong and the transformer was tapped incorrectly. here is a list.
It'd be easier to make a list of the things I didn't un-do...
Tremolo switch, new 8-pin octal tube socket, one 20 mfd / 500 Volt filter cap.
But here's a run-down of the things I either put back the way they were, or reworked/rewired/or replaced:
-Replaced original power cord and repaired the end. (it is longer and more rugged)
-Removed Copper-Cap (half-wave) rectifier module and replaced with ultra-fast recovery expatial diodes (full-wave)
-Removed Choke -- replaced original voltage divider resistors.
-redesigned (and relocated) bias adjustment circuitry to work with higher voltages now present.
-Replaced 100 mfd/350 Volt capacitors with original 220/285's (They are fine, and best if larger value on the UL)
-Replaced 2 other bad Mallory 20/500 caps with Sprague TVA type. (they were bad)
-Properly wired voltage dropping resistors under capacitor cover. (they were reversed)
-Replaced 'presence' resistor under tone stack.
-Adjusted feedback resistor for minimal global negative feedback. (820 ohms is way too much)
-Fixed improperly wired tremolo tube socket.
-Entirely rewired LondonPower FPM kit to eliminate oscillations. (reorganized and used smaller sheilded wire)
-Fixed reversed values of bass and mid caps on channel 2
-Rewired output jacks to accomodate multi-tap secondary of output transformer and present proper impedances.
-Replaced line-out jack (it does not limit power.)
-Replaced weak 6L6 tubes
New work:
-Replaced all film capacitors with Sprague Orange-Drops
-Built and installed control board for LondonPower ERK (channel-switch) kit.
-Cleaned all tone controls on channel 2.
-rerouted wires to tremolo tube to eliminate 'thump' when tremolo on.
----Still working on why tremolo intensity is too low