Channel Switching for JCM 800 2204

[sabredude]

I'm looking for a design to do channel switching on a JCM 800 style amp without changing the appearance of the amp. I found a Kevin O'Connor design in his ultimate tone series but I wanted to see who had other ideas.
I liked Kevin's idea of bypassing the cascaded tube pre but didn't really like the plan for feeding the clean channel back into the power amp section. It seemed like it would dramatically change the way the amp worked and didn't seem to have a good option for setting a different master volume for the clean channel which seems somewhat necessary. I'd really like to see your ideas.

I'd rather not add a gain stage or additional tone circuits - perhaps put a second master volume in the DI hole in the back.

I like the idea of using the low gain input for my channel switch jack and use the high gain input for both channels. Thoughts?

[roberto]

It sounds better if you use two gain pots and two masters, bypassing the 2nd gain stage for the clean channel.

I personally prefer to bias the second stage hotter and then switch two gain and MV independently.

[sabredude]

do you have a sample schematic showing how you would do that?
Thanks!

[pgambon]

Try Ace Pepper Custom Amps site. Under Useful Info he post a schematic for his Powermatic 50. Basically what your looking for. I used this channel switching concept in a Tweed Twin successfully. Check it out!

[The Ballzz]

I'm looking for a design to do channel switching on a JCM 800 style amp without changing the appearance of the amp. I found a Kevin O'Connor design in his ultimate tone series but I wanted to see who had other ideas.
I liked Kevin's idea of bypassing the cascaded tube pre but didn't really like the plan for feeding the clean channel back into the power amp section. It seemed like it would dramatically change the way the amp worked and didn't seem to have a good option for setting a different master volume for the clean channel which seems somewhat necessary. I'd really like to see your ideas.

I'd rather not add a gain stage or additional tone circuits - perhaps put a second master volume in the DI hole in the back.

I like the idea of using the low gain input for my channel switch jack and use the high gain input for both channels. Thoughts?

I will soon have a small pile of 1 meg dual concentric pots that may be quite useful for your needs. Check this thread:

https://tubeamparchive.com/viewtopic.php?t=25754

HTH,
Gene