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Where to get G&L 1M reverse log pots?

11/13/2005 1:04 AM
Chris/CMW amps	Where to get G&L 1M reverse log pots? Hi all Yesterday a customer did bring his G&L Legacy (Strat style guitar) when picking up his modified '59 Bassman Ltd. That guitar does have a volume-control, a treble-control (mastertone) and a bass-control (cap across 1M rev. log pot). The range of the controls was pretty good so I wanna try this circuit in one of my Strats just for fun. Anyone knows where to get a quality 1M rev. log pot with a "guitar-knob-style-shaft"? Many tia! Chris

11/13/2005 1:04 AM

Chris/CMW amps
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Where to get G&L 1M reverse log pots?

Hi all

Yesterday a customer did bring his G&L Legacy (Strat style guitar) when picking up his modified '59 Bassman Ltd.
That guitar does have a volume-control, a treble-control (mastertone) and a bass-control (cap across 1M rev. log pot). The range of the controls was pretty good so I wanna try this circuit in one of my Strats just for fun.
Anyone knows where to get a quality 1M rev. log pot with a "guitar-knob-style-shaft"?

Many tia!

Chris

11/13/2005 3:55 AM
Chris/CMW amps	found this but... http://www.glguitars.com/shopping/shopdisplayproducts.asp?id=4&cat=Electronic%20Parts The type (log, rev, whatever ) isn't specified. Chris

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11/18/2005 7:09 PM
Steve A.	Chris: I really doubt that the pot in the link would be reverse audio. There's a 60% chance that it would be audio taper and a 40% chance that it would be linear taper- at least that is the odds in Vegas. For a reverse audio taper you can always use a regular audio taper pot and wire it backwards; the rotation would be reversed but you'd set it to 0 to simulate 10 and vice versa. You might compare this to a linear pot to decide if you really need to get a RA pot. Steve Ahola

11/18/2005 7:09 PM

Steve A.

Chris:

I really doubt that the pot in the link would be reverse audio. There's a 60% chance that it would be audio taper and a 40% chance that it would be linear taper- at least that is the odds in Vegas.

For a reverse audio taper you can always use a regular audio taper pot and wire it backwards; the rotation would be reversed but you'd set it to 0 to simulate 10 and vice versa. You might compare this to a linear pot to decide if you really need to get a RA pot.

Steve Ahola

11/19/2005 3:27 AM
Chris/CMW amps	Hi Steve I did check some G&L wiring diagrams and the ones with the bass-control did show "R" on a couple and "1M reverse audio" on one. I've tried comparable circuits in amps and the reverse log did give the nicest range/"adjustment feel". Anyway: I really did like the working of the controls in that G&L Legacy. Back to a HotRod Deville.... Chris

11/20/2005 11:12 AM
Steve A.	Chris: Here are some links I found for reverse audio pots (the Weber ones are the closest but they evidently have a rotary off switch on them): http://www.guitarelectronics.com/product/CPC500R https://weberspeakerscom.secure.powweb.com/store/potsord.htm http://www.state-elec.com/ModularPots2.asp So is this the circuit that you are talking about? http://www.glguitars.com/schematics/Legacy_schematic_blockdiagram.pdf Steve Ahola

11/20/2005 11:12 AM

Steve A.

Chris:

Here are some links I found for reverse audio pots (the Weber ones are the closest but they evidently have a rotary off switch on them):

http://www.guitarelectronics.com/product/CPC500R

https://weberspeakerscom.secure.powweb.com/store/potsord.htm

http://www.state-elec.com/ModularPots2.asp

So is this the circuit that you are talking about?

http://www.glguitars.com/schematics/Legacy_schematic_blockdiagram.pdf

Steve Ahola

11/20/2005 4:24 PM
Chris/CMW amps	Hi Steve Many thanks! Hope it's possible to order "a couple" from G&L ($5/each). And yes, that's the diagram. Maybe it's also because of the used pickups but the adjustment-ranges of all pots were just excellent. All Weber pots I did use did have "amplifier-knob-shaft, just looking for such pot that can be used with Strat-knobs. Again: thanks! Chris

11/21/2005 9:46 AM
Steve A.	D'oh! Chris: I should have noticed this earlier, but... the bass pot is wired as a variable resistor, not a potentiometer (2 wires as opposed to 3). I believe that if you wire up the "top half" of a 1M audio taper pot, you will get the reverse audio taper. (Normally you would connect a tone control to the "bottom half"- the wiper and the CCW terminal- the terminal normally grounded on a volume control.) However, I do suspect that G&L might be using a special taper for the bass pot- not just reverse audio but something different than a typical 10% taper. If you still have the guitar around maybe you can unsolder one of the terminals and then write down the ohms for each position from 0 to 10. Steve Ahola

11/21/2005 9:46 AM

Steve A.

D'oh!

Chris:

I should have noticed this earlier, but... the bass pot is wired as a variable resistor, not a potentiometer (2 wires as opposed to 3). I believe that if you wire up the "top half" of a 1M audio taper pot, you will get the reverse audio taper. (Normally you would connect a tone control to the "bottom half"- the wiper and the CCW terminal- the terminal normally grounded on a volume control.)

However, I do suspect that G&L might be using a special taper for the bass pot- not just reverse audio but something different than a typical 10% taper. If you still have the guitar around maybe you can unsolder one of the terminals and then write down the ohms for each position from 0 to 10.

Steve Ahola

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