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I didn’t see any rules against posting builds that involve other manufacturer’s boards, but please excuse me if this is inappropriate.
What I have here is a super simple LM386-based distortion. My goal is to omit the tone circuit and volume control and to replace those with the Tone TwEQ. I also want to add an option for diode clipping with the Roto-tone Deluxe. I essentially have two questions, bolded and italicized below.
I’ve had a hard time wrapping my head around the Roto-tone, but I think I have it figured out.
Hopefully someone can confirm that I do or don’t with feedback on this.
In the diagram below, what I’ve tried to do is to jump off the distortion board after R5 by going out from C6 to the Roto-Tone pad A. Pad C is going back to the distortion board where C6 is going to ground. Pad B is going to the In on the Tone TwEQ board. In position 1, A is jumped to B, so there is no diode clipping. In positions 2-4, A is jumped to B and there are pairs of diodes going from A to C, which, again, is going to ground.
Also, I’d like to confirm that I’m jumping off the distortion board at the right spot.
I really appreciate any input you can offer. I have a bunch of these Roto-tone boards and this is my first attempt to put them to use. If I can get them right, I have a bunch of guitarpcb boards that I hope to mod with them for my next projects. Thanks!
Hey stranded. No, there are no rules against what you have posted or asked. We’ll help when we can. Whether you have your head wrapped around the RTD I don’t know, but your connections should provide the circuit you describe. Whether it works as intended you’ll have to see. You could have jumped off before R5, but in this case, and if the circuit proves to be too much input for the TT and causing unwanted distortion, then the C6 spot can be used for a resistor to create a voltage divider in order to lessen the signal strength. Just an observation. I read that you breadboard a lot. Breadboard yourself a roto-tone and have a blast with experimentation. IMHO the RT doc does an excellent job showing and describing its functions. Perhaps you will discover a new idea. Let us know.
I’m just now getting to build this. I’m looking at the Tone TwEQ schematic and it looks like there’s a lot more that I can — and in fact should — remove. R5 and C6 on the distortion board both need to go. I need to jump off the circuit after C4, using the adjacent leg on R5 for the wire leading to the ROTO and TwEQ boards. C on the ROTO board needs to go anywhere to ground.
For the TwEQ board, here’s my thinking: I don’t need the pulldown resistor (R1), and it would also create a filter with C4 on the distortion board. I also don’t need C2, as that would place two caps in series. C4 on the distortion board will do the work of coupling the circuits and filtering very low frequencies before the op-amp on the TwEQ can boost them. So it would seem that I should attach the TwEQ board at the C2 leg adjacent to R2, eliminating the need to add a jumper at C1, between the input and R2. Does that seem right?
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