Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bakerlite on October 24, 2014, 06:42:01 am

Title: has anyone ever modded the short channel on ab763 for extra gain/breakup?
Post by: bakerlite on October 24, 2014, 06:42:01 am
I have a spare chassis and transformers for a super reverb. I even have a tank somewhere. I am debating wethether or not to do a single chanell build or the two cgannell version.
To be honest the only use if the short channel would be if it was the same as stepping on a ts808 or something like that. I have no need for two clean channels.
I like the idea of an AB pedal and using it to use the clean term channel for rhythm and then the modded channel for lead.
Has this been documented?
Title: Re: has anyone ever modded the short channel on ab763 for extra gain/breakup?
Post by: sluckey on October 24, 2014, 06:54:46 am
Here's a simply mod that I have done on a couple AB763 preamps. The raw control looks just like a mid control except the pot value is much higher. This lifts the tone stack to give a signal boost and a raw tone.
Title: Re: has anyone ever modded the short channel on ab763 for extra gain/breakup?
Post by: tubenit on October 24, 2014, 08:04:30 am
You can get a BIG gain increase with the PAB (preamp boost) and midboost of this design.  I have this footswitchable with relays on my Tweed BluezMeister and use these features. 

With respect, Tubenit

Quote
I have a spare chassis and transformers for a super reverb. I even have a tank somewhere. I am debating wethether or not to do a single channel build or the two channel version.

IF I had that available to me ........... it would become a cathode biased dumblish amp.

Title: Re: has anyone ever modded the short channel on ab763 for extra gain/breakup?
Post by: tubenit on October 24, 2014, 08:39:06 am
Here's a couple of more ideas you could consider.  I have NO agenda for you, just tossing stuff out that may possibly fit with your original post description.

With respect, Tubenit
Title: Re: has anyone ever modded the short channel on ab763 for extra gain/breakup?
Post by: jjasilli on October 24, 2014, 04:33:56 pm
A Torres / Rivera mod is to re-wire that channel for Marshal tone.   This is essentially a mid boost along the lines that Tubenit mentions.