one cathode two tone stacks ?

[phillyhudson]

has anyone experience of using two tone stacks from a single cathode ? any interactions between channels/pops on switching over ?
I was trying to build a channel-switching marshall type amp and wanted separate tonestacks for the clean and overdrive [trying to save putting an extra valve in ] - can somebody with greater experience than mine have a look at the following two examples of slightly different ways of implementing the two tonestacks please ?

A.pdf

B.pdf

ta,

phil

[Lauri]

If you have DC on the relay like in B.pdf it will pop and very loudly. You need to put a capacitor after the cathode follower and resistors to ground from all the 3 pins of the relay to make sure it doesn't pop.

Here's an example how I've done it in one of my amps.

Screenshot From 2025-04-06 13-26-10.png

[phillyhudson]

thanks lauri that's very helpful - does the extra capacitor effect the sound in any way ?

[R.G.]

does the extra capacitor effect the sound in any way ?

The simple answer is "not if it's big enough".

If the capacitor is large enough to have its low frequency roll off with the tone stacks be below any frequencies you feed it, almost certainly there will be no audible effect.

[phillyhudson]

right then - I'm going in....