Channel Switching Advice

[Ninevolt]

Hello, new to the forum, first post, looking for advice on channel switching.
I've build a few one channel tube amps and want to try a two channel clean/dirty. I haven't nailed down what I'm going to do with each channel, just trying to figure out the best way to isolate each preamp channel from their respective input and output. I think I might be over thinking it? I made a pic of a basic topology for switch placement (this is for example). Advice/Opinions/Criticism is welcome.

1. Is this overkill? Can I get away with something simpler?
2. Placement of the input ground shunt before or after the grid stopper?
3. Thoughts or personal opinions on relays vs mosfets, I'm thinking of buying a Ch Sw kit to implement it.

[Enzo]

A zillion Fender and other amps... WHy have separate input stages? Why not have one input stage to lift the guitar signal? You really don't want a lot of junk between the input and the first grid it sees.

[Ninevolt]

I was thinking to use different tubes and topologies for each channel input so i could swap out for voicing. The pic is just for example on trying to figure out the best way to isolate the channels. I haven't nailed it down but I was thinking of something like a 12au7 cascode for the clean and 12ax7 parallel for the dirty.
This line of thinking I have may not work.

[Enzo]

You can try any circuit you like. My concern is any switching and passive controls you put before the first gain stage will increase noise and such.

[Chuck H]

IMHE you'll want a more complete design before arranging for channel switching. Designing the channel switching first means you may be limiting tone shaping options to accommodate the switching circuits. That should never be the case. Design for the sound/s you want first and THEN design the switching.

And yes, your switching arrangement is overkill for the job. You can get away with fewer switches. And there's almost always a way to dual purpose an on/on switch rather than using multiple open/shut switches.

[Ninevolt]

I was hoping there was a way to avoid mixing input stages. I'll run the clean CH input stage into the dirt CH to cut the noise. Ty!

[Chuck H]

In that case I'd say to look at the Fender Prosonic schematic. It uses a universal first stage, switches the dirt channel stages in/out and switches/grounds the output of the dirt stages when not in use. Three switches. Though the Prosonic uses an extra switch that is the universal power supply trigger for the other three. That's not necessary, but YMMV.

[Justin Thomas]

In that case I'd say to look at the Fender Prosonic schematic...

Look At? Just clone the thing! Add a few very minor improvements & you could have a small army following you. All the people who want one but have been looking for one for years and can't find one.

No, I don't own mine any more. Dad bought it for his kid; been looking for two years. Now it gets gigged regular-like.

Justin

[Chuck H]

Look At? Just clone the thing! Add a few very minor improvements & you could have a small army following you. All the people who want one but have been looking for one for years and can't find one.

No, I don't own mine any more. Dad bought it for his kid; been looking for two years. Now it gets gigged regular-like.

Justin

I've been thinking about building a stripped down version. It would only take three preamp tubes!!! And, as you know, has all the gain you'll need and sounds better than the hordes of five preamp tube uber gain metal monsters. Of course you don't get a reverb or effects loop. Whoop de doo. I hardly use 'em. And I wouldn't miss them much.

P.S. Since the Prosonic preamp is the source for all it's clipping you can strip the vibrato out of a Vibro Champ and build in the Prosonic preamp with only two preamp tubes. I've done it.

[Ninevolt]

Prosonic? Not my cup of tea, some good ideas in there though TY!
I have the PA/PSU nailed down out now its choosing 1 of 3 Pre designs I have figured out and tweaking to make it all fit. I don't know if I'll go with the zillion+1 or zillion-1 option as I procrastinate too much. Probably take a month to choose and another two to build with trial n error on placement.

[Chuck H]

Prosonic? Not my cup of tea, some good ideas in there though TY!
I have the PA/PSU nailed down out now its choosing 1 of 3 Pre designs I have figured out and tweaking to make it all fit. I don't know if I'll go with the zillion+1 or zillion-1 option as I procrastinate too much. Probably take a month to choose and another two to build with trial n error on placement.

If you post a schematic you're much more likely to get suggestions on channel switching. There are definitely particulars with design. The skeletal drawing you posted is pretty limited for suggestion. If you have something "proprietary" to protect I suppose you're on your own.?,.