Pres-set volume switching pedal

Rob DiStefano · April 30th, 2008, 10:02 PM

Nephew Andre (Rosie Ledet Band) needed a way to quickly switch from rhythm to lead without resorting to twiddling the guitar's volume knob.

Hmm, a bit of sketching and I came up with a simple passive switching circuit utilizing a pair of 500k pots, two jacks, a special 3PDT stomp switch, a battery clip and a pair of LED's (green and red) and the appropriate LED voltage resistors. A small cast pedal box competed the deal.

The circuit itself is passive and the extra poles on the switch allowed the use of LED's to show which vol pot is selected. I layed out the components into the case for proper fit, drilled out the holes, and used some handy rattle can color spray on the box followed by a few spritzings of clear. Everything fit into the case nicely and wiring was easy ...

Plugging a guitar in kicks on the battery to show what pot gets selected, run the box to any FX and on to the amp, preset each vol pots to the desired level, hit the footswitch for instant volume selection. Fun stuff.

Wardpike · April 30th, 2008, 10:10 PM

Clever!

woodman · May 1st, 2008, 11:36 AM

dang, i've been wishing for something like that since 1973!

BB · May 1st, 2008, 11:39 AM

Freaking brilliant! Your nephew is lucky to have an uncle like you.

Rob DiStefano · May 1st, 2008, 11:49 AM

If y'all like, schematic, parts inventory and sourcing to follow ...

woodman · May 1st, 2008, 01:34 PM

Rob, where would you put this in the signal chain?

getbent · May 1st, 2008, 01:42 PM

Rob, that is cool! I'll look forward to the parts list... I'm gonna build a couple of them!

Rob DiStefano · May 1st, 2008, 02:27 PM

Quote:

Originally Posted by woodman

Rob, where would you put this in the signal chain?

Immediately after the guitar and before any FX and amp.

Rob DiStefano · May 1st, 2008, 04:35 PM

Pots. jacks and 9V battery clip can be sourced from most anywhere, the resistors, LED's and LED holders are from Radio Shack, the special 3PDT switch and the case came from www.effectsconnection.com

Hooking up LED's is really easy. The longer lead is positive (hot) and the shorter lead negative (ground). In order to supply the proper voltage to each LED when using a 9v battery, apply the following formula to determine the proper resistor for each LED ...

battery voltage minus LED voltage divided by LED milliamp draw

2.6v 28ma LED example ...
9v - 2.6v = 6.4v / .028ma = 228.6 ohms (or the closest higher value)

FMA · May 1st, 2008, 04:42 PM

Very cool idea, Rob.

Rob DiStefano · May 2nd, 2008, 06:50 AM

Anyone having questions about building this pedal, please PM or email.

Rob DiStefano · May 2nd, 2008, 07:22 AM

Same volume switcher pedal circuit, but without the LED indicators ...

telel6s · May 2nd, 2008, 10:46 AM

Hey Rob,

Why did you go with two pots? Why not just one pot:

Pedal Off: Guitar straight through
Pedal On: Volume pot sets lower level

Also, is there going to be any tone changes if one of the volume pots is rolled way back (like on a tele without the extra resistor thingy on the volume pot)?

Rob DiStefano · May 2nd, 2008, 11:13 AM

Quote:

Originally Posted by telel6s

Hey Rob,

Why did you go with two pots? Why not just one pot:

Pedal Off: Guitar straight through
Pedal On: Volume pot sets lower level

Also, is there going to be any tone changes if one of the volume pots is rolled way back (like on a tele without the extra resistor thingy on the volume pot)?

The pair of pots allows for any use of an A/B box, where one side goes dry and the other to the Volume Switcher. There are LOTS of combinations and options of ins and outs.

There's always issues of passive units affecting tone (heck, that's also true of active circuit - and maybe more so with them!), and the original circuit had bleeders in both vol pots but I found that overkill for single coil guitars. Optionally, bleeders could be added on a switch and selected as needed (or not). So many options, the pedal can be tweaked for one's precise needs.

Yer just a foot stomp away from "Heaven and Hell" or "Nice 'n' Nasty"

Rob DiStefano · May 8th, 2008, 07:10 AM

Another "Switcheroo" gittin' assembled ...

Green = "Nice" ........ Red = "Nasty"

April 30th, 2008, 10:02 PM	#1 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	Pres-set volume switching pedal Nephew Andre (Rosie Ledet Band) needed a way to quickly switch from rhythm to lead without resorting to twiddling the guitar's volume knob. Hmm, a bit of sketching and I came up with a simple passive switching circuit utilizing a pair of 500k pots, two jacks, a special 3PDT stomp switch, a battery clip and a pair of LED's (green and red) and the appropriate LED voltage resistors. A small cast pedal box competed the deal. The circuit itself is passive and the extra poles on the switch allowed the use of LED's to show which vol pot is selected. I layed out the components into the case for proper fit, drilled out the holes, and used some handy rattle can color spray on the box followed by a few spritzings of clear. Everything fit into the case nicely and wiring was easy ... Plugging a guitar in kicks on the battery to show what pot gets selected, run the box to any FX and on to the amp, preset each vol pots to the desired level, hit the footswitch for instant volume selection. Fun stuff.

May 1st, 2008, 11:36 AM	#3 (permalink)
woodman Poster Extraordinaire Join Date: Nov 2004 Location: Mint Hill, NC Age: 62 Posts: 5,961	dang, i've been wishing for something like that since 1973! __________________ Truth is stranger than fact ... www.myspace.com/woodymitchellmusic BAND PAGES: www.myspace.com/stragglerswing (Stragglers - Western Swing) www.myspace.com/loafersgloryband (Loafers Glory - '70s country-rock)

May 1st, 2008, 01:34 PM	#6 (permalink)
woodman Poster Extraordinaire Join Date: Nov 2004 Location: Mint Hill, NC Age: 62 Posts: 5,961	Rob, where would you put this in the signal chain? __________________ Truth is stranger than fact ... www.myspace.com/woodymitchellmusic BAND PAGES: www.myspace.com/stragglerswing (Stragglers - Western Swing) www.myspace.com/loafersgloryband (Loafers Glory - '70s country-rock)

May 1st, 2008, 01:42 PM	#7 (permalink)
getbent Moderator Doctor of Teleocity Join Date: Mar 2006 Location: San Benito County, California Posts: 10,154 37 Photos	Rob, that is cool! I'll look forward to the parts list... I'm gonna build a couple of them! __________________ 'never pet a burning dog'

May 1st, 2008, 04:35 PM	#9 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	Pots. jacks and 9V battery clip can be sourced from most anywhere, the resistors, LED's and LED holders are from Radio Shack, the special 3PDT switch and the case came from www.effectsconnection.com Hooking up LED's is really easy. The longer lead is positive (hot) and the shorter lead negative (ground). In order to supply the proper voltage to each LED when using a 9v battery, apply the following formula to determine the proper resistor for each LED ... battery voltage minus LED voltage divided by LED milliamp draw 2.6v 28ma LED example ... 9v - 2.6v = 6.4v / .028ma = 228.6 ohms (or the closest higher value) Last edited by Rob DiStefano; May 4th, 2008 at 08:46 AM.

April 30th, 2008, 10:10 PM	#2 (permalink)
Wardpike Tele-Holic Join Date: Feb 2008 Location: St. John's, Newfoundland Age: 43 Posts: 652	Clever!

May 1st, 2008, 11:39 AM	#4 (permalink)
BB Friend of Leo's Join Date: May 2003 Location: Pacific NW Age: 53 Posts: 3,145	Freaking brilliant! Your nephew is lucky to have an uncle like you.

May 1st, 2008, 11:49 AM	#5 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	If y'all like, schematic, parts inventory and sourcing to follow ...

May 1st, 2008, 04:42 PM	#10 (permalink)
FMA Tele-Afflicted Join Date: Apr 2003 Posts: 1,129	Very cool idea, Rob.

May 2nd, 2008, 06:50 AM	#11 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	Anyone having questions about building this pedal, please PM or email.

May 2nd, 2008, 07:22 AM	#12 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	Same volume switcher pedal circuit, but without the LED indicators ...

May 2nd, 2008, 10:46 AM	#13 (permalink)
telel6s Tele-Afflicted Join Date: Jun 2003 Location: Northern Virginia Posts: 1,176 80 Photos	Hey Rob, Why did you go with two pots? Why not just one pot: Pedal Off: Guitar straight through Pedal On: Volume pot sets lower level Also, is there going to be any tone changes if one of the volume pots is rolled way back (like on a tele without the extra resistor thingy on the volume pot)? __________________ Mama always said, "A little tone is good for the soul."

May 8th, 2008, 07:10 AM	#15 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,782	Another "Switcheroo" gittin' assembled ... Green = "Nice" ........ Red = "Nasty"