How to wire a 3pdt to bypass a bmp tone control?

[MonsterBass101]

So I was wondering how to to wire a 3pdt switch to bypass the tone section of a big muff pi for increased mids.  or even better, a switch that could activate a mids switch so I could adjust it.  Thanks.

[Heemis]

Actually, it's as simple as lifting the resistor and capacitor in the tone stack from ground.  This can be done with as little as a SPST switch.  Instead of grounding the leads of the 22k resistor and .01uf cap in the tone stack, connect them to one end of a SPST switch, and connect the other end to ground.  Flipping the switch will bypass the tone control, voila!

Here's a schematic for reference:

[MonsterBass101]

Ok so how would I wire that to a 3pdt?  I wanna have it as a footswitchable option.

[stringsthings]

here's some good info on BMP tone circuit variations:

http://www.buildyourownclone.com/board/viewtopic.php?f=24&t=19898

[Hides-His-Eyes]

Ok so how would I wire that to a 3pdt?  I wanna have it as a footswitchable option.

You would just leave the lugs hanging, although unless you have far too many 3PDT or far too much money, you should probably just order a SPDT 'no LED, lossy bypass' style switch next parts order, or at least a DPDT, which still tend to cost about half as much.

[Heemis]

Hides-His-Eyes is right, it is a bit wasteful to use a 3PDT where a SPST would suffice, but if you really want all you need to do is wire the leads that need to be grounded to one of the center lugs of the switch, and then wire either the lug directly above or below that lug to ground.  That way when you switch you will be grounding, and ungrounding those leads.  Something to be aware of though:  When you bypass the tone control you will encounter a large boost in volume that might make the "footswitchable" aspect of your mod unusable.  You might want to consider using one of the other lugs of the 3PDT to wire in a fixed resistor to tame the volume boost. 

If it were me, and I had a 3PDT lying around to use on the mod, I'd use one pole to bypass the tone section, one lug to switch in a fixed resistor to match the volume levels, and one pole to switch an LED to indicate I was in tone bypass mode, but it's your journey!

[MikeH]

You can also acomplish this by jumering the junction of the 0.004 cap and 39k resistor with a spst or spdt, etc.  FYI- You're also going to get a massive volume boost when you bypass the tonestack.  Which is cool if that's what you want, but not if you don't.

[GibsonGM]

You can also acomplish this by jumering the junction of the 0.004 cap and 39k resistor with a spst or spdt, etc.  FYI- You're also going to get a massive volume boost when you bypass the tonestack.  Which is cool if that's what you want, but not if you don't.

Yeah...temporarily tack in a pot as a 'volume control' for this, and see what resistance value gives you unity.  Then replace the pot with a fixed resistor (or hey, leave it a pot if you like, for solo boosts!!). 
Hook the whole deal up in a larger enclosure, and you can have that 2nd switch for tone stack bypass.  Good deal )

[MonsterBass101]

Good Ideas guys.  I think I'm going to cave and get two small SPDT Switches and wire one to bypass the tone section, and use the other to remove the first two diodes of the first stage.  Can anyone send me a link or visually show me how to wire the SPDT Switch to remove the first two diodes?  I know how to do it for one component, but not for two in parallel.

[Hides-His-Eyes]

If it were me, and I had a 3PDT lying around to use on the mod, I'd use one pole to bypass the tone section, one lug to switch in a fixed resistor to match the volume levels, and one pole to switch an LED to indicate I was in tone bypass mode, but it's your journey!

I like this idea a lot morethan what I said!

[MikeH]

Can anyone send me a link or visually show me how to wire the SPDT Switch to remove the first two diodes?  I know how to do it for one component, but not for two in parallel.

just lift the one end of both components and wire the free end to the switch.  The other end of the switch is wired back to where either diode was connected.  Since the diodes are connected together in the circuit, you can use a single pole switch to break the connection as if it were just one component.  if it were two independent components, you'd have to use a switch with two poles (a dpdt, for instance).