Multiple Component Switching

[Scruffie]

Right... I still can't grasp switching components on a circuit but I want to do a few switchable mods to someones black russian big muff, any links to help with component switching would be greatly appreciated aswell but here's what I want to do.

I want to be able to raise the value of the capacitor and resistor in a Big Muff tone stack via a single DPDT switch that can go between the new raised values and stock so that I can add mids to the tone control so how would I go about wiring that... I assume you can do it on one DPDT

Then on a 3PDT I want to be able to ground Q3s Emitter at the same time as rasing the 10k Resistors that are after the sustain .1uF and Q2 1.uF cap

Are these mods possible to do simply with a switch? If not I suppose i'l have to find a work around.

Cheers for any replies & help.

[mth5044]

If you can understand how a the switch works, you can understand how to make your switching work. There are plenty of DPDT switch working schematics that could help you out, but I will let you google that at your leisure. But I can tell you that in order to raise the mids, you don't necessarily have to change both the capacitor and a resistor. On my BMP, I have a mid switch that goes between scooped, flat an boosted (using a center off DPST). I would suggest downloading Duncan's Tonestack calculator (free) and use the BMP tonestack. Substitute in the parts in the tonestack schematic that matches the parts in your BMP and see how just changing one part changes the overall EQ, I think you might find you could make it as easy as switching one cap.

Anyway, to do your switching with two caps and two resistors, here is what I would do. Remove the original parts from the PCB. Solder a wire coming out of where the cap or resistor was on the PCB, but make sure you take the wires from the first part of the PCB, by that I mean if you look at a schematic, where the signal comes to first is where you want the wires. Solder each wire to a middle lug on the switch (I will draw a little ASCII picture at the end  ) Wire the cap on one lug that is connected to the middle lug where the.. hell just look at this picture


              Cap 1 ----- [ ]   [ ] ----- Resistor 1

From PCB (cap) ----- [ ]   [ ] ----- From PCB (res)

              Cap 2 ----- [ ]   [ ] ----- Resistor 2


Then wire the output of the two caps together and back into the vacant hole in the PCB. Then do the same for the resistors. In one direction, Cap 1 and R 1 will be function together, activate the switch and you will have Cap 2 and R 2

[Scruffie]

Google has a terrible problem of being filled with completely useless information though which is a shame, but perhaps my search terms weren't clear enough.

I understand how a switch works fine yeah I think it's the case of running items in series and parallel that confuses me although I don't think it's applied here, It's just one of those things that hasn't become nature yet as I haven't implied it to a circuit.

Oh yeah, I used the tone stack calculator and came up with what I wanted and changing the 2 worked best for me with the values on hand.

Funnily enough I was just drawing out a diagram and that's what I came up with, it makes sense now that i'm looking at it that it's no different from switching 2 components with an SPDT, i'l just have to try and remeber this for next time though, I was thinking running the components into the same holes on the PCB would cause a problem.