Thermionic Deluxe idea

[DGWVI]

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]

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.

 

[DGWVI]

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.

Yeah, I'd like it all to be accessible through footswitches if possible

 

[Chuck D. Bones]

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]

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]

I'll work up a sketch & post it. The only thing I'm not sure about is on the A/B switch: is the LED ON when ch A is selected, or is it on for ch B?

 

[DGWVI]

Thanks. Haven't wired it up yet, so someone else will have to chime in

 

[the_grumpy_gnome]

I'll work up a sketch & post it. The only thing I'm not sure about is on the A/B switch: is the LED ON when ch A is selected, or is it on for ch B?

Pictures of sketch-ups are suuuuuper useful

 

[Chuck D. Bones]

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]

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.

 

[bifurcation]

I'd love to hear some sound clips when you're done.

 

[DGWVI]

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

 

[DGWVI]

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.

So, this wiring diagram does work. Thanks again.
Buuutt... Getting the stack to sound good means A and B don't sound ideal alone. Tested outside of a box, but noise didn't seem all the much higher with each circuit alone. Was worth the experiment, but I'm just gonna keep it stock. Loves being slammed with a Rat, though

 

[Jiuk]

A few months ago,, I connected both pedal serially. but it makes a broken sound - useless, IMHO.