Two inputs for A/B switching?

[alfi27]

Hi guys,

I'm currently in the process of modding my old JCM800, drilled up for an additional preamp tube and the whole nine... As only one half of the additional tube is used for adding gain, I figured I could use the unused half to make a simple clean channel similarly to the natural channel on the Orange Rocker 30 or the clean channel on the Friedman Runt 20.

The initial plan was to make the low sensitivity input the clean channel, and the high sens. the gain channel so I could either use it as a single channel amp or switch between the two (A/B box) without having to jerk around with relays. Only problem is, which I learned quickly, that I cannot have two master volumes connected to the grid of the phase inverter at the same time without having some kind of switching mechanism to cut one or the other off.


Now, this is first and foremost going to be a 4 stage modified Marshall (with the Suhr/CAA SE Lead mod), and that is priority numero uno. The clean channel/input would have been a really nice addition, but if it can't be done I'll put it on a push pull instead. If it can be done though, the amp would be pretty much perfect for what I want it to do!


Thanks for reading, cheers!

[pdf64]

...make a simple clean channel similarly to the natural channel on the Orange Rocker 30 or the clean channel on the Friedman Runt 20...

Schematics? Neither seem to be in the public domain.

If you don't want channel switching, why not just used channel mixer resistors at the phase splitter input, like a regular BF/SF 2 channel Fender?

[fred.violleau]

Oups modded as I read that you don't want relay.

Fred.

[alfi27]

Thanks for the response, but I gave up on that idea and just made it into a full blown 4 stage hot rodded Marshall! The SE Lead mod if you've heard of it