Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mguitarworks on March 11, 2012, 04:18:13 am

Title: How To Remove The Reverb Circut From a AB763 TWIN
Post by: mguitarworks on March 11, 2012, 04:18:13 am

HI guys, i want to remove the reverb circut from my AB763 Clone,

(yes, i have already pulled the tube, disconnected the wires to the tank ect)

i not sure about the rest though..mixing resitor, reverb transformer and will the rest of the circut still be fine with the reverb removed(extra voltage ect)

cheers thanks

Title: Re: How To Remove The Reverb Circut From a AB763 TWIN
Post by: LooseChange on March 11, 2012, 06:53:13 am

Good question. I would't worry about the voltages but I've always wondered about the unloaded reverb transformer if the driver tube was left in... Will it burn up?

Title: Re: How To Remove The Reverb Circut From a AB763 TWIN
Post by: tubenit on March 11, 2012, 07:51:32 am

Disconnect the RT from B+. With the reverb tank unplugged and the tube removed, you should be fine.

Out of curiousity, why do you want the reverb removed from the Twin? 

with respect, Tubenit

Title: Re: How To Remove The Reverb Circut From a AB763 TWIN
Post by: sluckey on March 11, 2012, 08:19:01 am

Look at the Showman...

http://www.el34world.com/charts/Schematics/files/fender/SHOWMAN_AB763.pdf (http://www.el34world.com/charts/Schematics/files/fender/SHOWMAN_AB763.pdf)

Title: Re: How To Remove The Reverb Circuit From a AB763 TWIN
Post by: Willabe on March 11, 2012, 09:58:00 am

You might want to leave the verb mixer stage in.

It's been said many times over the years that even guys who don't use any reverb still prefer the sound of the verb channel (with no reverb) over the sound of the same BF model that doesn't have on board reverb.

You could leave that in, only the verb  _ mixer stage _ (disconect the verb return stage), try it, than pull that tube and jumper around it to see which you like better?

Even for clean sounds it can sound fuller, warmer.

OTOH, like tubenit asked, why do you want to take it out? Unless your tryin to free up a couple of tubes to use for something else, why not just turn off the verbs volume?

                        Brad      :icon_biggrin: