Calling all Gretsch Wiring Experts

[Janglin_Jack]

I have an old Electromatic that have some Filtertrons in it. This guitar only has two pots, so I tried wiring them straight to the output jack with no tone pots. I find that I need some tone control. Before I opt to a single volume and single tone, I thought I might try to wire in a fixed value that would simulate a tone knob in the circuit. How would I wire in caps/resistors that would simulate a tone knob fully on 10 for the neck PU and like on 8 for the bridge? I think it has been argued that if the pot is on 10, that there is no treble bleed, but it seems to me that it must be doing something in the circuit, even on 10. This would be with 500K pots. Any tips on how to wire something like this?

Mike

 

[GuitarDoc]

Re: Calling all Gretsch Wiring Experts

You're not going to hear a difference between a 500k tone pot on 10, and no pot.

For a bridge tone pot on 8, if it's a linear pot you would want a 100k resister. For a log pot you'd probably need in the neighborhood of 25k.

But to me this seems like a futile exercise that really won't tell you anything. A lot of Gretsch guitars had a three position tone switch which did like you are asking about. I took it out of mine and put in a pot because I wanted to control/fine tune my tone.

 

[freefrog]

Re: Calling all Gretsch Wiring Experts

I have an old Electromatic that have some Filtertrons in it. This guitar only has two pots, so I tried wiring them straight to the output jack with no tone pots. I find that I need some tone control. Before I opt to a single volume and single tone, I thought I might try to wire in a fixed value that would simulate a tone knob in the circuit. How would I wire in caps/resistors that would simulate a tone knob fully on 10 for the neck PU and like on 8 for the bridge? [...] This would be with 500K pots. Any tips on how to wire something like this?

Mike

To do what you want, you just have to solder a resistor in series with a tone cap, then to solder the whole between the "hot" wire of each pickup and the ground.
For the bridge pickup, just take a 500k or a 470k (since actual resistance is often lower than theoretical one in guitar pots).
For the neck, it depends on the curve that you want... The taper of pots varies widely in real life. To help you in your choice, there's a bunch of graphs showing the resistance of pots at different positions and allowing to guess which is their resistance @ 8/10. Examples among others;

https://www.planetz.com/more-on-selecting-pots-and-evaluating-tapers/

http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

I think it has been argued that if the pot is on 10, that there is no treble bleed, but it seems to me that it must be doing something in the circuit, even on 10.

Objectively and outside of any argument, the difference between a 500k pot full up and no tone pot is approximatively of 3dB @ resonant peak. That's why Fender has mounted "no load" tone pots in some guitars. People "may or may not" find it noticeable, according to their individual sensitivity and gear (if a dark or warm guitar amp or cab is used, the mentioned difference will be way less obvious than through a bright rig).

Good luck in your experiments!

EDIT - BTW, I've a guitar with a pair of TV Jones Classic. The bridge PU is paired with a push pull no load (disabling the tone pot)... that I never use: it's way too plain and bright without tone control.
Of course, it might be different with another instrument (there's no rule here).

 

[beaubrummels]

Re: Calling all Gretsch Wiring Experts

You're not going to hear a difference between a 500k tone pot on 10, and no pot.

For a bridge tone pot on 8, if it's a linear pot you would want a 100k resister. For a log pot you'd probably need in the neighborhood of 25k.

But to me this seems like a futile exercise that really won't tell you anything. A lot of Gretsch guitars had a three position tone switch which did like you are asking about. I took it out of mine and put in a pot because I wanted to control/fine tune my tone.

And to kind of piggy back on that, I found I leave my volumes dimed as the Gretches I have with individual volumes and a master sound dull if I turn any of the volumes down more than a notch. I wouldn’t think just a single master would be a bad thing.

 

[Janglin_Jack]

Re: Calling all Gretsch Wiring Experts

And to kind of piggy back on that, I found I leave my volumes dimed as the Gretches I have with individual volumes and a master sound dull if I turn any of the volumes down more than a notch. I wouldn’t think just a single master would be a bad thing.

On my 6120 I put in a treble bleed circuit and it help as you turn down the volume knob. I forget the values I used, but I dialed it in and love it.

I will probably grab a pot and measure the resistance at around 8 and go from there. So I would need to install the capacitor after the resistor and then attach to ground? I will have to think about where it should go, as resistance is only part of the tone pot, it needs the capacitor to set what amount of top end signal is sent to ground.

 

[freefrog]

Re: Calling all Gretsch Wiring Experts

So I would need to install the capacitor after the resistor and then attach to ground? I will have to think about where it should go, as resistance is only part of the tone pot, it needs the capacitor to set what amount of top end signal is sent to ground.

The order of these components doesn't matter: it can be resistor then cap to ground OR the contrary. With a 500k resistor the cap is going to bring a subtle difference anyway (although it should slightly alter the harmonics according to the capacitive value selected).

For the record, what you think to mount is exactly what I have in one of my main stage guitars fitted with a single volume control. IME, this "fixed tone network" works well with bright pickups.

 

[Janglin_Jack]

Re: Calling all Gretsch Wiring Experts

The order of these components doesn't matter: it can be resistor then cap to ground OR the contrary. With a 500k resistor the cap is going to bring a subtle difference anyway (although it should slightly alter the harmonics according to the capacitive value selected).

For the record, what you think to mount is exactly what I have in one of my main stage guitars fitted with a single volume control. IME, this "fixed tone network" works well with bright pickups.

Awesome FreeFrog..thank you! Will work on it later this week and report back.

Mike

 

[Janglin_Jack]

Re: Calling all Gretsch Wiring Experts

I got out my multimeter, soldering iron and parts box. I tested a pot with the volume rolled back a little, I decided to try out ~360K ohms for the bridge with a .0047uf cap, (seems to be the value used in the Gretsch mud switch). For the neck I used 470K ohm resistor and .022uf cap. It sounds great!! I need to give it a whirl with the band at full volume but in my living room at modest volume it sounds like...a Gretsch!!

Thanks,
Mike