ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.	New: view Recent Searches. New: visit Schematic Hell! The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

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
email

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

Thursday

Book Of The Day

The Ultimate Tone, Volume III by Kevin O'Connor

Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

Note: The Ampage Archive is an Amazon Associate site. A small commission is paid to the site owner on any qualified purchase made after clicking an associate link such as the one above.

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

Page 1 of 2

Next>

Last Page>>