Source Needed For Slider Style Audio Potentiometers That Will Retain Tone

[cadmus]

Can anyone recommend a brand and/or source for slider style potentiometers that embody most of these features:
-have an audio taper
-retain the timbre and tone of woody acoustic guitars
-are 1 meg-ohm or as close as possible 
-are smooth enough for volume pedal use
-are rugged enough for volume pedal use
-are long lasting enough for frequent use
-are cheap

Why are slider pots never seen on volume pedals? 

Thanks in advance for the help.

[CodeMonk]

Slider pots are likely not used because when you rock the pedal, the ends move in an arc, not in a straight line.

Check mouser

[cadmus]

Check mouser

Thanks for the response.  I will investigate the mouser website, thanks for that lead.

Slider pots are likely not used because when you rock the pedal, the ends move in an arc, not in a straight line.

I do not find that to be a problem.  90% of them use racks that are straight on the rack and pinion gears when they should use and arc as well.  




Is there anything about the durability, signal taper, or electrical characteristics that would make a slider pot unusable? more prone to poping? more prone to tone loss? 

[R.G.]

-are smooth enough for volume pedal use
-are rugged enough for volume pedal use
-are long lasting enough for frequent use
-are cheap

Good, easy, cheap: you may choose any TWO. This seems to be one of those hidden laws of the universe.

Smooth linear pots are usually not rugged. Smooth, rugged linear pots are not cheap. Cheap linear pots are usually not reliable.

Why are slider pots never seen on volume pedals? 

IMHO, the mechanics needed are more difficult to make reliable. I do know of at least one volume pedal that used a linear pot, though. I know the designer, he's a bright guy, and he went through about a dozen different tries at making that work, then went to rack and pinion.

[cadmus]

Most sewing machine foot pedals use sliders, I have seen many different ways to do it, some work better than others.  

Also I have seen several versions of this:https://www.youtube.com/watch?v=W9UMVkmM1RM

[CodeMonk]

Durability might be an issue unless you can figure out a way to reliably seal a a slider pot.
Maybe sealed ones exist somewhere though.

And yeah, rack and pinion design are on many wah/volume pedals.
But the rack and pinion design does allow for an arc to rotate a pot.
A slider pot needs to be actuated in a straight and even line, otherwise you would stress and wear things out rather quickly.

I'm not saying it could not be done, you would just have to figure out a way to move that slider that doesn't apply to much stress to it.
Some kind of pulley system maybe. But I doubt the reliability of that.

[cadmus]

Good, easy, cheap: you may choose any TWO. This seems to be one of those hidden laws of the universe.

I said "most" not all.  But yeah, i agree.  I should have said maximize some of these qualities.  Everything is a compromise otherwise there would only be one of everything on the market.  
And even expensive pots are normally affordable so forget cheap.

[cadmus]

Good call on Mouser, CodeMonk.

http://www.mouser.com/ProductDetail/Bourns/PTL45-15O0-105A2/?qs=sGAEpiMZZMukHu%252bjC5l7YccZ8g5H32GW6LbeuF1agUc%3d
http://www.mouser.com/ProductDetail/Bourns/PTL45-15G0-105A3/?qs=sGAEpiMZZMukHu%252bjC5l7YccZ8g5H32GW%2f%2fPfom1prh8%3d


I wish these cost more so i would be more sure of it's quality.  

[mistahead]

Sliders work, theremins work, chains and gears work. They just don't work well in mass produced "sell and forget" setups.

Think outside the box a little - a cry baby rocker pedal is (at best) only OK ergonomics, the rocker volume makes more sense.

Two plates, top one sliding in a groove on the base plate, groove is actually a slider type VR's path - extrapolate and you have an interactive pedal that swings a variable...

Just saying.  

[R.G.]

I liked the FX17 wah's approach to an rocker. The treadle slid a metal plate past a PCB etched with a triangular area. The capacitance between the PCB copper area and metal plate varied as the treadle moved. This changed the frequency of an RF oscillator which made a control voltage. Simple mechanics, linear, rugged. Cheap.

[mistahead]

Nicely done - I like that idea...

Now who wants to fill me in on whether there is an spray on resistive coating? Blend layers/thickness on a "sword in the box" type runner aluminium/copper runner making contact with a contact down the runners the coating acting to turn the whole thing into a big contact VR

Actually - the "sword in a box" could also work with a light source in a tube with a progressive opacity - clear at end A and solid opaque and end B, LDR instead of a contact, as the sword slides down the runner the LDR is exposed to a varied brightness.

Hmmm Kinect, SDK, PC, digital switching, virtual pedal board... 

[CodeMonk]

Nicely done - I like that idea...

Now who wants to fill me in on whether there is an spray on resistive coating? Blend layers/thickness on a "sword in the box" type runner aluminium/copper runner making contact with a contact down the runners the coating acting to turn the whole thing into a big contact VR

Actually - the "sword in a box" could also work with a light source in a tube with a progressive opacity - clear at end A and solid opaque and end B, LDR instead of a contact, as the sword slides down the runner the LDR is exposed to a varied brightness.

Hmmm Kinect, SDK, PC, digital switching, virtual pedal board... 

Isn't or wasn't there some company that used an LED/LDR (or some sort) and a widening slit in some material the determined how much light was let through to the LDR part?

[Lurco]

Morley

[mistahead]

I have a couple of dozen light dependant (effected.?) transistors ... Wrapped in old pc mice.

Any info on how to test, measure or implement these? Or if it is worth it..?

Please excuse iPad formatting!

[cadmus]

Isn't or wasn't there some company that used an LED/LDR (or some sort) and a widening slit in some material the determined how much light was let through to the LDR part?

Morley is optical.  but it suffers from tone suck.  lots of tone suck.  I have tried several optical models and still own one.  They remove all timbre and tone.

others brands are optical:
All Hilton Pedals
some Goodrich pedals
some DeArmond pedals (went out of business)

[Mark Hammer]

1) My Visual Sound Visual Volume pedal uses a dual-ganged slider pot.  I'm sure others use them too, but where one can use off-the-shelf solutions to move a rotary pot of any kind that has a 1/4" shaft, every little difference in slider-pot dimensions requires a different mechanical solution and unique machining.  Bottom line: not as cost effective as rotaries.

2) No pot *type* sucks more tone than any other, althugh mismatches in pot value to the impedance of the signal source will suck tone.  A high value like 1M is appropriate if trying to passively attenuate a direct signal from a pickup/guitar, but if one is using suitable buffering, pot value should be moot.  One of the reasons why so many guitar players complain about tone sucking in volume pedals is because they unintentially buy/use a volume pedal intended to stick after a keyboard or other low-impedance source (often using a 50k pot).

3)  There is a reason why so many mixing boards and control consoles that undergo high duty use slider pots: they ARE dependable, precise, sturdy, smooth.  They ARE more susceptible to invasive dirt unless suitably protected, and they DO require a well-planned mechanism to avoid stressing the pot, but meet those requirements and there is no reason why they shouldn't deliver years of service.  A friend who operates a busy and well-respected studio records masters to 2" tape on an analog board with 4" sliders.  He recommended a product to me that he swears by to keep his pots running smooth and crackle free, called Stabilant.  I use it.  Just amazing stuff.