Gretsch style "mud switch"

[EsquireEsque]

Hi,

the set up would be:
Filtertron (TV Jones "classic Plus" or "Power'tron")
Volume pot.

Ideally - I'd like for a volume push/push pot to affect the guitar's tone output: I see two options for this:

(1)
My understanding is that this could be done if I used a push/pull 250k/500k (dual value) pot. I'd get basically a tone bypass form a 500k pot and another tone bypass from a 250k pot - with the 250k pot providing a "warmer" or "darker" tone.

That presents problems because the only such pot I can see is a "fender CTS pot" with a short shaft - so I wouldn't be able to use it if I put the pot in through the back of the guitar (I'd have to use a control panel).

(2)
I also understand that if I put a resistor across one of the positions of a dual 500k pot I could achieve the same two "tones" (but apparently this might have problems when tapering the volume - which becomes "on /off" - I assume this is when an audio pot is used - I wonder if it's a problem if a linear pot is used?) As per this Picture (although I've no idea where to position this on a dual pot):






The alternative is to use a "mud switch" similar to this (pretending that there is only one pickup "where the selector switch is" connected to the volume pot):


... which I think is:
Switch lug 2 (one of teh middle connections) connected to volume pot
Switch Lug 1 connected to "cap 1" (which is grounded to back of volume through the "other" middle connection) and
Switch Lug 3 connected to "cap 2" (also grounded to back of volume through the "other" middle connection)



........or to use a dual tone pot which I think is this here:


or here:


So If anyone is aware of a dual value push/pull pot available in Australia that'd be great.

If not - and someone knows how to position a resistor to emulate the above - and also knows how to mitigate the taper - that would be much appreciated.

Otherwise could someone confirm the "mud switch" picture (pretending that it's a single pickup and that in the picture that pickup'd be where the "selector switch is)......

Last choice is a dual tone pot - but I think that picture is clear enough even for me (I assume a ground wire also goes from the casing to the back of the volume pot?).


please note - the above pictures represent the extreme maximum for me in this - I have absolutely no understanding of electrical diagrams using symbols -or anything complicated...

[WeirdBits]

It comes down to knowing how dark you want the tone, and how much you use the volume control.

If you typically run full volume then the taper has no effect, and even with a 500k in parallel it will just give a more linear taper when it is engaged. The overall darkening of the effective 250k pot will depend on the pickup and how dark you want it.

If you want a true ‘mud’ style switch with a push/pull you could just add either a .003uF or .012uF cap to ground, or even both with a trim pot between them so you can dial in the mud you want. Again, it depends on your ear.

For something like this where you don’t necessarily know what value components you want until you hear them and get your ‘sound’, it’s helpful to install the pickup but use clip leads to test different parts until you find what you want.

pickup - volume - output - clip on { pot (adjust amount of mud) - .003uF <-> .012uF caps - ground}

[fender3x]

What sort of guitar you plan to put this circuit in? When I think of Gretsch guitars I tend to think about the hollow bodies. If you are going to do some experimenting to dial in just the right amount of mud, you will probably want to do it on a board outside the body. This is hardest on semi-hollow guitars where the wiring loom has to be worked through the F-hole (you also need to make sure all the parts you install will actually pass through the F-hole) A bit easier on a fully hollow where it can go through the pickup hole. Much easier if you are putting it into a Telecaster ;-) and only need to take out a couple of screws to get to the tone stack.

[EsquireEsque]

"For something like this where you don’t necessarily know what value components you want until you hear them and get your ‘sound’, it’s helpful to install the pickup but use clip leads to test different parts until you find what you want.

pickup - volume - output - clip on { pot (adjust amount of mud) - .003uF <-> .012uF caps - ground}"

Thanks "WeirdBits"- I hadn't thought of using clips to test.
Obviously you are referring to a push/pull tone pot.

[EsquireEsque]

What sort of guitar you plan to put this circuit in? When I think of Gretsch guitars I tend to think about the hollow bodies. If you are going to do some experimenting to dial in just the right amount of mud, you will probably want to do it on a board outside the body. This is hardest on semi-hollow guitars where the wiring loom has to be worked through the F-hole (you also need to make sure all the parts you install will actually pass through the F-hole) A bit easier on a fully hollow where it can go through the pickup hole. Much easier if you are putting it into a Telecaster ;-) and only need to take out a couple of screws to get to the tone stack.

It's to be put in a solidbody, so putting it together on a board forst should be relatively easy (If I understand what that is correctly!).

[EsquireEsque]

I've just found out that the Fender dual value pot is not a push/pull pot.

So I'm thinking it's possible to use it as a volume pot with a toggle switch in order to get the two "tones".....

So my limited understanding is that volume and switch is:
.... from pickup to switch to each pot and then from each pot to output..... or
.... Pickup to each pot, from each pot to switch and from switch to output.....

[fender3x]

If I understand correctly a dual value pot would be like this?



You could probably do that with a toggle switch, but it would be simpler to wire it more like the switch in your original guitarwiringblogspot pic. In fact, that pic is a mud switch.* Your toggle switch would need to be a 3 position DPDT (on-off-on) switch. In the middle position it does nothing. In the upper position it adds one of the caps to the circuit, in the lower position it adds the other. In the pic it's an alternative (or addition) to a tone pot. On a normal tone pot with the pot wide open it's not actually doing anything. That would be like the middle position on the switch. As you turn the knob on a normal pot, it shunts more and more of the high frequencies to the ground...making the sound "darker". With the switch the caps would be sort of like two preset stops on the tone control.

If what you are after is darkening the tone, I suspect that adding caps (either with a pot or a switch...or both) would get closer to the effect you want than adding a resistor or dual pot.


* I read about it here:
https://gretsch-talk.com/threads/wha...tch-etc.15313/

[EsquireEsque]

If I understand correctly a dual value pot would be like this?



You could probably do that with a toggle switch, but it would be simpler to wire it more like the switch in your original guitarwiringblogspot pic. In fact, that pic is a mud switch.* Your toggle switch would need to be a 3 position DPDT (on-off-on) switch. In the middle position it does nothing. In the upper position it adds one of the caps to the circuit, in the lower position it adds the other. In the pic it's an alternative (or addition) to a tone pot. On a normal tone pot with the pot wide open it's not actually doing anything. That would be like the middle position on the switch. As you turn the knob on a normal pot, it shunts more and more of the high frequencies to the ground...making the sound "darker". With the switch the caps would be sort of like two preset stops on the tone control.

If what you are after is darkening the tone, I suspect that adding caps (either with a pot or a switch...or both) would get closer to the effect you want than adding a resistor or dual pot.


* I read about it here:
https://gretsch-talk.com/threads/wha...tch-etc.15313/

Yes -that looks like it one pot is 500k the other 250.

My understanding is that a bypass (no cap, no tone pot) on a 250k volume pot will sound "darker" that it would on a 5ook pot.
If caps are needed for either pot - they can be put on after.

So the options would be:
500k volume pot - "normal" Filter'tron sound without a tone pot
250k volume pot - "darker" sound without a tone pot.

[fender3x]

It would be a little darker, yes. I would test it first, since it might be a pretty subtle effect. If you have a pot with each value you could try them before purchasing the dual pot. See if you even hear the difference.

You could get close to the same effect with a 500K push pull pot by adding a 500K (or 470K as in the pic) resistor. All you would need to do is run the one leg of the resistor to the output leg of volume pot. Run the other leg of the resister to the left center contact on the switch. Run a wire to ground/earth from either the top or the bottom left contact on the switch, depending on whether you want the dark sound to be the up or the down position. That would be pretty close to the same effect as using a switch to go between the two gangs of the dual pot--and you wouldn't need a visible switch. It should sound exactly the same as the dual pot in 500K mode. With the volume all the way up, it would sound the same in 250K mode as well. The only difference would be that the taper would be a little flatter when you turn it down in 250K mode...All the same sounds you get with a normal taper would be there, just in a little different place than with standard taper.

The 500K pot with push pull would have another advantage. If the resistor trick does not get the sound dark enough for your tastes, you could swap it for a smaller value resistor (a 125K resistor would make a 500K pot equivalent to 100K)...or you could swap for a cap. Gretsch wires their mud switch with .012 or .039 caps I think. So you'd have more options to try.

[EsquireEsque]

It would be a little darker, yes. I would test it first, since it might be a pretty subtle effect. If you have a pot with each value you could try them before purchasing the dual pot. See if you even hear the difference.

You could get close to the same effect with a 500K push pull pot by adding a 500K (or 470K as in the pic) resistor. All you would need to do is run the one leg of the resistor to the output leg of volume pot. Run the other leg of the resister to the left center contact on the switch. Run a wire to ground/earth from either the top or the bottom left contact on the switch, depending on whether you want the dark sound to be the up or the down position. That would be pretty close to the same effect as using a switch to go between the two gangs of the dual pot--and you wouldn't need a visible switch. It should sound exactly the same as the dual pot in 500K mode. With the volume all the way up, it would sound the same in 250K mode as well. The only difference would be that the taper would be a little flatter when you turn it down in 250K mode...All the same sounds you get with a normal taper would be there, just in a little different place than with standard taper.

The 500K pot with push pull would have another advantage. If the resistor trick does not get the sound dark enough for your tastes, you could swap it for a smaller value resistor (a 125K resistor would make a 500K pot equivalent to 100K)...or you could swap for a cap. Gretsch wires their mud switch with .012 or .039 caps I think. So you'd have more options to try.

Hi,

I do not have any spare parts..... so what I buy will be what I "experiment with".

After a bit of extra research - I've realised that using a resistor is going to change the way the volume is tapered - which will make the guitar "inconsistent" - so I think it's not a real option.

It's either
using the double pot and swapping with a switch...... or simply using a 500k pot and using a switch with caps.
simply using a volume pot straight to output.

I'd like the top of the guitar to be as simple as possible (ideally, just the bridge, pickup and on e knob).

I wonder if I could put a recessed slide switch in the back of the guitar.