Search found 10 matches

by xenrelic
Tue Feb 06, 2024 5:56 am
Forum: Dumble Files
Topic: Vibroverb RI Dumble Hybrid Mod
Replies: 1
Views: 3027

Re: Vibroverb RI Dumble Hybrid Mod

Posted some updates to the schematic in the original post attachment if anyone wants the latest schematic of the Vibroverb Dumble Hybrid.
by xenrelic
Sat Nov 14, 2020 6:45 am
Forum: Fender Discussion
Topic: Fender 'The Twin' Red Knob Version Mods and Repairs
Replies: 14
Views: 17442

Re: Fender 'The Twin' Red Knob Version Mods and Repairs

Here's a different version of the mod that was applied to a similar Fender Red Knob Dual Showman Reverb Head. It's a bit less involved and for people that don't want to mod their clean channel, because they're pretty happy with it. I'd say this mod is more for people who like the stock clean channel...
by xenrelic
Fri Jul 03, 2020 12:30 am
Forum: Dumble Discussion
Topic: Popping again.....Cap across channel switch?
Replies: 45
Views: 7731

Re: Popping again.....Cap across channel switch?

You will always have pop when switching cathode resistors, one for another with a mechanical switch. You should try the J175 P-Channel switch as they work great for silent cathode resistor and capacitor switching, when you have the larger value cathode resistor always in circuit and switching in ano...
by xenrelic
Mon Apr 01, 2019 7:01 am
Forum: Fender Discussion
Topic: Fender 'The Twin' Red Knob Version Mods and Repairs
Replies: 14
Views: 17442

Re: Fender 'The Twin' Red Knob Version Mods and Repairs

Yep, that was a typo. C305 for the series screen supply filter was supposed to be C306. It was difficult to read from the schematic I was using. I fixed the O.P. above to reflect that change.
by xenrelic
Tue Dec 19, 2017 8:31 pm
Forum: Dumble Files
Topic: Dumbleator Layout
Replies: 67
Views: 76089

Re: Dumbleator Layout

Here's the Triad R-2C power transformer spec sheet with dimensions for the Dumblelator.

Image
by xenrelic
Mon Mar 20, 2017 8:22 am
Forum: Fender Discussion
Topic: Fender 'The Twin' Red Knob Version Mods and Repairs
Replies: 14
Views: 17442

Fender 'The Twin' Red Knob Version Mods and Repairs

Thought I'd share some excellent sounding mods for the Fender 'The Twin' Red Knob Combo. The amp stands up to high dollar boutique amps after the following mods. - Power Supply Section: Bias supply filter C303 = 100uF 100v F&T C304 = 100uF 100v F&T C305 = 100uF 100v F&T C202 = 100uf 100v F&T Series ...
by xenrelic
Mon Sep 30, 2013 4:16 am
Forum: Dumble Files
Topic: Vibroverb RI Dumble Hybrid Mod
Replies: 1
Views: 3027

Vibroverb RI Dumble Hybrid Mod

Here's a '63 Vibroverb Reissue with some Dumble Hybrid modifications. For those that love the AB763 style circuit with the clean channel capability of the ODS. This amp sounds amazing with the mods! The normal channel is set up with a little extra drive for nice pushed singing driven tones. Feel fre...
by xenrelic
Thu Mar 15, 2012 1:29 am
Forum: Technical Discussion
Topic: Source for Magicparts Transformer???
Replies: 13
Views: 5071

Re: Source for Magicparts Transformer???

I have a used Dumble TF-170 output transformer that was removed to be replaced with a TF-135 years ago. If anyone wants it, hit me up.