Stereo Guitar amp build

[Toxophilite]

Hi I'm going to build a stereo guitar amp out of an old hammond (A-100 reverb amp I think) chassis and a GUlbransen organ tube power amp. Both amps have 2 EL84 output tubes with their own OTs



I use a roland space echo RE-150 that allows me to separate dry and echo but I like to run some dry into my echo amp so I don't loose the big stereo sound when I turn off the echo.

I normally use my super and a small 2 channel amp but I have a single amp build in mind(with two single 12" cabs that fit together to carry)

The hammond has all the room and 3 12AX7 style sockets so I was thinking I'll build all the preamps there. would use 2 and run one through the Gulbransen amp for the echo and use the hammond amp for dry

Anywho

What I would like to know is can I make my preamp section 2 channels and then run a line from the dry channel pre phase splitter through a pot into the echo amp (pre phase splitter) so I can mix in some dry to the echo amp.
Would I need some sort of separating resistor and or an isolating transformer?

I have built a couple of little deluxes and a vibrolux , all succesfull as well as a bunch of pre conversions so I have some experience.

[d95err]

You'll need to mix the signals somehow. We'll need to know more about the schematics or your build to help you with how to mix the signals.

If you're using a long-tail phase inverter on the echo amp and no negative feedback, you could use the phase inverter as a mixer (like the two channels on the Marshall "18-watt" amp).
Another option is to adapt a schematic of an effect loop that can be mixed from series to parallell operation.
A simple passive mixer might work just fine though.

[Toxophilite]

Hi Thanks for your reply

The Hammond is actually an AO-34 from an L-100(which I believe is commonly used for guitar amp conversions,I'll work on getting a schematic) In the manual I believe it's the reverb/poweramp)) and The Gulbransen is an APS-25 There is a gulbransen manual here that has a schematic for the APS-22 and amp in the exact same chassis and tube layout, the schematic is on page 22 http://www.jimmyandsharonwilliams.co..._664DEJVKF.pdf

[Toxophilite]

Or even better

[Toxophilite]

THat went well
Here it is properly

[Kasanay]

FYI:
One of the schematics for the APS-22 / APS-25 that has been floating around the interweb has a error within the power supply section.
I have attached a schematic with the correction noted.