Gretsch style "mud switch"

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):

Attachment 45639




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):
Attachment 45638

... 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:
Attachment 45636

or here:
Attachment 45637

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...

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}

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.

"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.

Quote:

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Originally Posted by 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.

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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!).

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.....

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

Attachment 45647

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/

Quote:

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Originally Posted by fender3x

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

Attachment 45647

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/

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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.

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.

Quote:

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Originally Posted by 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.

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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.

Makes sense to me! Also caps are cheap and easy to swap.

As to the switch on the back. I am sure it could be done with a sliding switch. On one of my first mods I did it with micro-switches on a G&L bass. On some basses G&L adds what players call an OMG cap that makes the pickup sound really boomy. Some people really like it, others don't. I didn't want to mess up the front of the bass, but I wanted to be able to turn them on and off. So I put the switches in an unused part of the control cavity, and recessed them so they couldn't be flipped accidentally. It worked like a charm, and is great for a setting that you want to be able to adjust, but that you don't need to adjust while you are playing.

Attachment 45648

Not very pretty, but I figured it was on the back ;-)

Quote:

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Originally Posted by fender3x

Makes sense to me! Also caps are cheap and easy to swap.

As to the switch on the back. I am sure it could be done with a sliding switch. On one of my first mods I did it with micro-switches on a G&L bass. On some basses G&L adds what players call an OMG cap that makes the pickup sound really boomy. Some people really like it, others don't. I didn't want to mess up the front of the bass, but I wanted to be able to turn them on and off. So I put the switches in an unused part of the control cavity, and recessed them so they couldn't be flipped accidentally. It worked like a charm, and is great for a setting that you want to be able to adjust, but that you don't need to adjust while you are playing.

Attachment 45648

Not very pretty, but I figured it was on the back ;-)

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.... and I thought it was my idea!

But that's pretty much what I was thinking - but for a sliding switch.

I've just come across a video where someone went to the trouble of switching pots so the difference could be heard.... I'm not sure it's any different from just using caps.....

So now it's just either a straight lead to the out put or by way of a switch with a cap....

Probably makes sense to go with the former but to "prep" for the latter.....

Rear mount slide switch(es) can certainly be done, as long as you don’t want to do any quick changes while playing.

If you decide to use a pot and a switch, then 3-way switches (mini or large toggle) can give you your clean and two different ‘mud’ options (half-way down this post gives you a few ways to do it).

For a single pot only layout, then a push/pull is your best option. Get some clip leads, a range of caps and resistors, and test until you find the sound you want.

Quote:

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Originally Posted by WeirdBits

Rear mount slide switch(es) can certainly be done, as long as you don’t want to do any quick changes while playing.

If you decide to use a pot and a switch, then 3-way switches (mini or large toggle) can give you your clean and two different ‘mud’ options (half-way down this post gives you a few ways to do it).

For a single pot only layout, then a push/pull is your best option. Get some clip leads, a range of caps and resistors, and test until you find the sound you want.

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Hi, thanks.

I think if I use resistors and a push/pull - then the tapering will be inconsistent.... that sort of kills the idea.

That is a very well done (and far more complicated) example of what I was thinking for the back switch...

AS to the build itself...... wow! It would seem you've done this before....

I actually meant you can use a resistor to reduce the amount of mud a particular cap adds to the sound, so you can have your preferred cap value but just less strong in its effect. That’s where the testing comes in.

Quote:

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Originally Posted by WeirdBits

I actually meant you can use a resistor to reduce the amount of mud a particular cap adds to the sound, so you can have your preferred cap value but just less strong in its effect. That’s where the testing comes in.

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I see - not what I thought.

However - I simply don't understand. So probably best to start with something that I think I can get my head around.

More and more I think it best to have a simple Pickup to volume to outbut... with a space that I can later put a switch in (whether on front - or in the back).

If the Fender dual value pot was push/pull as I originally thought it was - it'd be easier.

That would get you up and playing. Generally a good thing.

You can always test some caps later. To test, you wouldn't even need to open the control cavity with your setup. You could do it with an old guitar cable. Just cut it in half, and splice the shield wire (ground) and the center wire (hot) back together. Then alligator-clip one leg of the cap to each splice. That will give you a sense of how it will sound with the cap activated, should you ever decide to put in a switch.

If you decide to do some testing, eBay and places that sell small electronic parts, particularly places that sell them to guitar people, will often have "test kits" that include a few "chiclet" style caps in the values used by guitarists. These are generally cheap. If you have an electronics store nearby, you can often get a handful of them for pennies. If you get adventurous, you can also get a range of common guitar resistors for even less. You don't need to spend much, and it can be an eye opener.* I have a few caps in the standard values where I soldered alligator clips to the legs to use exclusively for testing. (That was an idea that came from Weirdbits, BTW)

This has been interesting to think about. I think I should be a little more conscious of how I use my tone control. I think that I don't sweep it all that much. I think I just find a place I like it and leave it in one or two places. I can see the benefit of having a couple of tone control settings pre-set, which would be quicker than trying to find the setting I like with a pot.


* I know that people will swear up and down that Sprague "orange drop" caps are much better...but I can tell you that Leo Fender used cheap chicklet style caps in his USA made G&Ls.

Quote:

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Originally Posted by fender3x

That would get you up and playing. Generally a good thing.

You can always test some caps later. To test, you wouldn't even need to open the control cavity with your setup. You could do it with an old guitar cable. Just cut it in half, and splice the shield wire (ground) and the center wire (hot) back together. Then alligator-clip one leg of the cap to each splice. That will give you a sense of how it will sound with the cap activated, should you ever decide to put in a switch.

If you decide to do some testing, eBay and places that sell small electronic parts, particularly places that sell them to guitar people, will often have "test kits" that include a few "chiclet" style caps in the values used by guitarists. These are generally cheap. If you have an electronics store nearby, you can often get a handful of them for pennies. If you get adventurous, you can also get a range of common guitar resistors for even less. You don't need to spend much, and it can be an eye opener.* I have a few caps in the standard values where I soldered alligator clips to the legs to use exclusively for testing. (That was an idea that came from Weirdbits, BTW)

This has been interesting to think about. I think I should be a little more conscious of how I use my tone control. I think that I don't sweep it all that much. I think I just find a place I like it and leave it in one or two places. I can see the benefit of having a couple of tone control settings pre-set, which would be quicker than trying to find the setting I like with a pot.


* I know that people will swear up and down that Sprague "orange drop" caps are much better...but I can tell you that Leo Fender used cheap chicklet style caps in his USA made G&Ls.

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Always good to think about things...

For me it's been quite informative.... some I understand annd some I don't (but that just makes obvious what is possible now and what is best left for later).

In a sense - the whole conversation validates what I originally though to do - but also makes me aware of how to avoid "retrofitting" in the future.