Double Tube Screamer

[Ctrl4Smilerz]

So, I've decided to dip my toes in DipTrace, in hopes to design a two in one tube screamer circuit. I started by replicating the circuit based on the Little Green Scream Machine circuit. I would like the circuit to have two of the clipping sections in series, which can be independently activated, but I have a few questions.

In the Little Green Scream Machine schematic the only switch is in the power section, are the two sections of the 3PDT unused, or does that just not show on the schematic? Since the switch is in the power section, would I need to replicate it for both clipping sections or is there a way I can reuse it for both? And finally can I keep just one output buffer that would go after the second clipping section? Thanks in advance for helping me.

 

[Robert]

There is no actual switch in the Little Green Scream Machine, what you're seeing is a single pad labeled "SW" that is grounded by the 3PDT to light the LED.

The 3PDT footswitch is not drawn on the schematic for the PCB.

If you are planning to incorporate the 3PDT footswitch into your PCB, then yes, you would use those unused portions for signal bypass switching.


As for your circuit... So you're wanting to duplicate the clipping stages only? What controls do you want to end up with?

 

[Ctrl4Smilerz]

There is no actual switch in the Little Green Scream Machine, what you're seeing is a single pad labeled "SW" that is grounded by the 3PDT to light the LED.

The 3PDT footswitch is not drawn on the schematic for the PCB.

If you are planning to incorporate the 3PDT footswitch into your PCB, then yes, you would use those unused portions for signal bypass switching.


As for your circuit... So you're wanting to duplicate the clipping stages only? What controls do you want to end up with?

That makes sense of the switch, thanks.

I would like to make it fit into a 125B enclosure so, the less I need to duplicate the better; I was thinking of just duplicating the clipping stages. Do you think that is enough to mimic the sound of two tube screens in series? Ideally the controls would be Tone, Drive, and Volume for both channels, so a total of 6 pots.