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Hoffman Amps Forum image Author Topic: AB763-2 Transformer Orientation with Mojo Chassis  (Read 1525 times)

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Offline StevenPituch

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AB763-2 Transformer Orientation with Mojo Chassis
« on: February 15, 2020, 10:09:47 am »
Hi All,
I have just finished the Hoffman AB-763-2 board and have received a Mojotone Deluxe Reverb chassis, Mojo0778 choke, Mojo0776 reverb transformer, and Mojo0768sp output transformer.  I was sort of stumped on how to mount these, but after doing a lot of research I think I have it right.  I have attached photo of how I think they should be mounted on the chassis.

The problem is that I didn't order the Mojo761ex power transformer yet (I'm on a budget), since it is located away from the fiberglass board, I thought I could install it later.  Looking at the pictures, I see the windings are enclosed, and I am wondering what the winding orientation is of the PT, as I want it to be 90 degrees from the OT.

1) Can you'all tell me if the choke and OT are orientated correctly?
2) Can you tell me if the wires coming from the choke and OT are in the right chassis holes?  (I think I've got this right.)

Sincerely,
Steve Pituch

Offline sluckey

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Re: AB763-2 Transformer Orientation with Mojo Chassis
« Reply #1 on: February 15, 2020, 10:25:06 am »
The choke needs to rotate 180° and put the two black leads in the same hole as the red, brown, and blue OT wires. As shown you have the choke wires in the hole for the bias pot. Since the bias pot is located on Hoffman's board, there will be nothing in the chassis hole for the mojo chassis.

Keep in mind that Hoffman's board looks nothing like the real Fender board. You will probably need to drill holes in the Hoffman board as well as the mojo chassis to mount that board. Best to drill those holes early on before doing any wiring.

Here are some pics for a real Deluxe Reverb that may be useful...

     http://sluckeyamps.com/64DR/index.htm
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline StevenPituch

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Re: AB763-2 Transformer Orientation with Mojo Chassis
« Reply #2 on: February 16, 2020, 03:43:48 pm »
Thank you Slucky for the info.  You got me on the right track.

Steve Pituch

 


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