Deluxe Reverb One vs. Two Channel

[plaidzebra]

On Doug's store, there are different transformers listed for the one-channel and the two-channel AB763 builds. Why are they different? Are there different power requirements for a Deluxe Reverb depending on whether it has one or two channels?

[EL34]

I am guessing you are talking about the parts list page?

http://hoffmanamps.com/MyStore/catalog/PartsListIndex.htm


One parts list is a Deluxe reverb and one is a Super reverb
Different power tubes and power ratings

[Fresh_Start]

I am guessing you are talking about the parts list page?

http://hoffmanamps.com/MyStore/catalog/PartsListIndex.htm


One parts list is a Deluxe reverb and one is a Super reverb
Different power tubes and power ratings

It depends on what tubes you plan to use in the single-channel Deluxe Reverb.  I might ask a question about the Mojo 762 "Heyboer for Bassman/Super Reverb spec also if I wanted to use 6V6s.  However, Doug Hoffman original documentation clearly shows 6L6s as the output tubes for the 1-channel AB763 project. 

http://el34world.com/Hoffman/images/AB763OldOneChannel.gif

If your goal is a Deluxe Reverb with a single channel, then the power transformer spec'd for the 2-channel AB763 probably makes the most sense.  Same cab, 12" speaker, etc. just one less 12AX7 preamp tube.

I probably wouldn't do it, but a Princeton Reverb power transformer might be fine for a low-power, 1-channel Deluxe Reverb provided you run only 6V6s.  There's only 1 more 12AT7 tube to power after all, and that adds heater current of only 300 ma.

With respect,
Chip

[EL34]

You can use the transformer set for deluxe reverb on my one or two channel baords


The board does not care what motor you install, it's still the same circuit on the board

[plaidzebra]

Roger, thanks for the response. So if I was going to make a one-channel AB763 with 6V6s, I'd use the Deluxe reverb transformer set instead of the Super reverb?

Another quick question: I'm running a two-channel Deluxe through a 2 10" speaker cab. Does the output transformer have enough power to drive both of those speakers if it was originally designed for a 1 12" cab?

[HotBluePlates]

Roger, thanks for the response. So if I was going to make a one-channel AB763 with 6V6s, I'd use the Deluxe reverb transformer set instead of the Super reverb?

Yes.

I'm running a two-channel Deluxe through a 2 10" speaker cab. Does the output transformer have enough power to drive both of those speakers if it was originally designed for a 1 12" cab?

"Enough Power" isn't the issue (you could drive 2x10's with 1/2w if you wanted, just wouldn't get as-loud).

Ideally, your output transformer has other secondary taps besides the stock 8Ω. 2x 8Ω speakers in parallel looks like a 4Ω load to the amp; output power will be reduced somewhat if attached to a tap expected 8Ω worth of load. 2x 8Ω speakers in series will look like 16Ω to the amp; again, power output will be reduced somewhat if attached to the 8Ω tap.

Of course, if you put 2x 16Ω speakers in parallel, that looks like 8Ω of load to the amp, and will result in stock power output.

[EL34]

Use the Heyboer/Mojo768sp with 4-8 and 16 taps and you will be golden 

http://hoffmanamps.com/MyStore/catalog/TubeSocketsMobile.htm

[plaidzebra]

Awesome! I used a ClassicTone transformer in my build with different impedance taps so I'm all set for now. Thanks for all the help!