Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: oheare on February 22, 2015, 01:11:49 pm

Title: Re: Hoffman AB763 one and two channel Turret Boards
Post by: oheare on February 22, 2015, 01:11:49 pm
Doug, I've got a silverface Deluxe Reverb chassis and cab that I'm planning on using for a build. My plan is to use the one-channel board, but add in a Vibro-King style reverb (with Tone, Dwell, Mix) at the front.

Will the whole works fit? And to whom should I talk about making the whole thing work? I can build anything, but my design skills are sadly lacking  :help:

Cheers!
Title: Re: Re: Hoffman AB763 one and two channel Turret Boards
Post by: EL34 on February 22, 2015, 01:17:09 pm
If you have not scratch built amps before you may be taking on more than you can handle?

Vibroking has a 3 knob reverb unit in the front end I think
That's not even close to the AB763 circuit

You need to find the exact circuit you want to build instead of trying to modify one.

Post on the main amp board so those guys can give you some info
Title: Re: Hoffman AB763 one and two channel Turret Boards
Post by: oheare on February 22, 2015, 10:50:34 pm
Thanks for the quick reply, Doug. Very much appreciated! And on a Sunday, no less...

I've scratch built amps, high voltage power supplies, all sorts of things; used to be certified for assembly/soldering/rework for Canadian Military electronics (haven't kept the certification up). I'm not worried about my construction skills. I can read a schematic well enough to build amps and such. My problem is the design, not the construction. I didn't make myself clear.

And yeah, I wasn't clear about the Vibroking vs. AB763 -- what I want is something like adding a 6G15 in front of a Deluxe, all in one box. *That's* what I meant about the reference to the Vibroking. The schematic that I have for the Vibroking shows the input hitting half the 12AX7 and the Dwell first, then through a 6BQ5/transformer, through the pan, then into the other half 12AX7 as reverb recovery, then into what would usually be the preamp section of the amp.

I'm a little confused, though -- you suggested the main amp board, I thought that was where I did post. What have I missed, where should I post? I see myself as posting in "Hoffman Amplifiers Forum » Amp Stuff » Tube Amp Building - Tweaks - Repairs".

I'm sorry to be such a pain.
Title: Re: Hoffman AB763 one and two channel Turret Boards
Post by: sluckey on February 23, 2015, 07:01:55 am
This is an ambitious project. I think your idea will fit in the DR chassis. The tube layout will work. Squeezing a Champ size OT into the space of the little reverb transformer might be a challenge. Doug makes a 6G15 board and a single channel AB763 board. But the combined board lengths is too long to fit. However, there is stuff on each of those boards that could be eliminated when combining. You could use those two boards as a basis to design a custom board. The resulting board could be made to fit the DR chassis. What I'm saying is you need a custom board made to your custom schematic, and it needs to be short enough to fit the DR chassis. That's a lot of design hours just to layout the board. Doug can drill the board using your provided layout.

BTW, you originally posted in the "Turret and Eyelet Boards " section and Doug moved the thread to this section.
Title: Re: Hoffman AB763 one and two channel Turret Boards
Post by: EL34 on February 23, 2015, 02:53:19 pm
There is a Vibro king schematic in the library here

It's mixed in with several other pages in the PDF file

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

Title: Re: Hoffman AB763 one and two channel Turret Boards
Post by: oheare on February 23, 2015, 08:26:34 pm
Thanks, folks! I'm a bit of a twit sometimes (well, more than sometimes :-)