Thermionic Deluxe idea

DGWVI

Member
So, I'm about to wire up my ThermDLX, and was wondering if anyone could help me figure out a way to add in a foot-switchable A into B option, while retaining the A or B functionality.
 

Willybomb

Member
I've done it with a two boosts and a rotary - A, B, or A->B. One footswitch for the whole thing but I suspect you want more functionality than that.
 

Chuck D. Bones

Active member
If you want to add a 3rd footswitch for series mode, the simplest way to wire it would make it behave this way:
switch 1 is ON/OFF.
switch 2 is A/B.
switch 3 is Series Mode. In series mode, the A/B switch doesn't matter.
Be warned: with that much gain on tap, the wiring layout is critical to avoid oscillation. You must keep the in and out wires far away from each other. Better to make the input wires shielded or twisted pairs (the other wire in the pair is ground).
 

DGWVI

Member
If you want to add a 3rd footswitch for series mode, the simplest way to wire it would make it behave this way:
switch 1 is ON/OFF.
switch 2 is A/B.
switch 3 is Series Mode. In series mode, the A/B switch doesn't matter.
Be warned: with that much gain on tap, the wiring layout is critical to avoid oscillation. You must keep the in and out wires far away from each other. Better to make the input wires shielded or twisted pairs (the other wire in the pair is ground).
I play scuzzy noise rock, so hiss and oscillation isn't too much of an issue for me. I'm just wondering how to wire it up
 

Chuck D. Bones

Active member
I ginned-up two versions, just double-checking them now before posting. Both require a 4PDT switch for the Series/Normal switch. Version 1 has no indicator LED for the switch. Version 2 has an LED, but the sacrifice is that Ch A input is always connected. Should not be a problem. If you go with v2, then I recommend changing R2a & R2b from 330K to 1M to minimize loading whatever is plugged into the input side when Ch B is selected. Again, I don't have one of these, so I'm guessing which pins on the A/B switch go to Ch A. If I'm right, then the series order is A -> B. If I guessed wrong, then it's B -> A.
 

Chuck D. Bones

Active member
OK, here it is. I was able to find a configuration with no compromises (no need to change R2a & R2b). In Normal mode, everything is interconnected exactly like the stock version. In Series Mode, the Input connects to Ch A input, Ch A output feed Ch B input and Ch B output connects to the Output. No changed to the the ON/OFF switch wiring. The LED on the Series/Normal switch lights up in Series Mode. If you don't need an LED on the Series/Normal switch, then you can use a 3PDT switch and wire the center pin on the A/B switch to GND. Someone should check this to make sure I didn't make any wiring errors.
 

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DGWVI

Member
OK, here it is. I was able to find a configuration with no compromises (no need to change R2a & R2b). In Normal mode, everything is interconnected exactly like the stock version. In Series Mode, the Input connects to Ch A input, Ch A output feed Ch B input and Ch B output connects to the Output. No changed to the the ON/OFF switch wiring. The LED on the Series/Normal switch lights up in Series Mode. If you don't need an LED on the Series/Normal switch, then you can use a 3PDT switch and wire the center pin on the A/B switch to GND. Someone should check this to make sure I didn't make any wiring errors.
Thanks! I'll get this finished up this weekend and report back

Edit: Don't have any 4pdt stomps, so i'm waiting on a shipment, now
 
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