Mixing/Grids for Skipped gain stage

[Bergheim]

I started to vizualise a circuit based on the layout you posted, but quickly concluded I'd have to draw a schematic myself to keep track of everything. Which I honestly don't have time to. But I'll chime in if I see a schematic here someday

[GlideOn]

How about just the first 1/4 of the amp then? The rest I'm sure is fine as it's more or less unchanged.

Edit: Here's the rest of the amp removed with just the first stage:

Soldano 1st stage B&W.png

Soldano 1st stage B&W.pdf

[Littlewyan]

I think this solution has a few issues. If you simply bypass a stage using this stereo jack then you'll have a long wire run coming out of the amp to your pedalboard and with a high gain lead stage that could pick up a lot of noise. Especially since it will be hanging like an antenna when not in use. The other issue is the volume drop, your boost pedal solution will bring the signal back up but you'll have to start clipping the stages to get back to the same volume level as the lead mode. So it won't be clean. You'd need a way of automatically turning up the master when switching to your clean mode.

If you're dead set on a proper clean channel do you mind not having the tone controls connected to it? You could have a single stage clean that you switch in with a relay which connects to a single volume pot and then onto the PI input? If your amp is exactly like the SEL Soldano layout we haven't got much room to play with unfortunately.

[GlideOn]

I think this solution has a few issues. If you simply bypass a stage using this stereo jack then you'll have a long wire run coming out of the amp to your pedalboard and with a high gain lead stage that could pick up a lot of noise. Especially since it will be hanging like an antenna when not in use. The other issue is the volume drop, your boost pedal solution will bring the signal back up but you'll have to start clipping the stages to get back to the same volume level as the lead mode. So it won't be clean. You'd need a way of automatically turning up the master when switching to your clean mode.

If you're dead set on a proper clean channel do you mind not having the tone controls connected to it? You could have a single stage clean that you switch in with a relay which connects to a single volume pot and then onto the PI input? If your amp is exactly like the SEL Soldano layout we haven't got much room to play with unfortunately.

You're correct in the the 'clean' won't be very clean. It still passes through the 39k cold clipper stage which makes it plenty dirty. However if you look at the layout you'll see I did have a way to clean that up that via the push/pull gain pot which effectively sends the first triodes directly to the tonestack and grounds the cold clipper stage via 1M grid resistor so it's kept stable and happy. But the Lead or High signal is also affected this way so it devolves into kinda an aggressive Plexi sound (220k plate) Still, I thought it was cool to have some options in voicings.

As to your point about 'long wire run coming out of the amp,' well doesn't the same thing happen anyway when a shielded instrument cable is plugged in, going to guitar with its' volume rolled to zero? Also the AB pedal in question is active and has isolation transformers to completely and quietly ground whatever side is not being used.

I made a diagram to help illustrate, carefully highlighted the High side and Low side, the other yellow color represents the ones that may need to be changing f the preceding stage mixers too heavily attenuate:

Soldano 1st stage B&W.png

Soldano 1st stage B&W.pdf

Forgive me, but I'm not quite seeing any signal leaving the amp? If you look once more you can see it's not wired the same way as the Robinette or typical JCM800 way where it slaves the connection to the Low jack. I have it in such a way where the Low connects directly to its' own gain pot, then get mixed at the second triode stage in amp, in this instance V1A. I'm not sure how any path of the High can be bled or suspect to excess noise other than through the connection of a regular shielded instrument cable.

The only thing I see potentially bleeding away useful signal is the mixing network into the second triode. I'm definitely not an expert in knowing how much signal is bled via voltage dividing, grip stoppers, etc. I don't even know what signal an SLO circuit needs from one stage to the next to operate the way it does. From experience, I suspect that anything between 100k and 470k is the ballpark though when it comes to mixing and voltage dividing in these kinds of amps.

It's a complicated scheme and a lot to digest, I admit. I really appreciate your time otherwise.