If we could design our own wah casing, what would we design in?

Started by MicFarlow77, May 03, 2008, 02:43:01 PM

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ugly_guitar_guy

Quote from: MicFarlow77 on May 07, 2008, 07:30:38 PM
Now, this post brings up some nice options....

For starters, I can build a mechanisim around slide pots very easily.. it would be easy to calibrate and would utilize all the pot travel. However, will slide pots work for all the possible options that a casing like this can offer... Wah, volume, controller etc.....

Also, doing a slide pot opens up several options for moving the slider that can give a really really smooth feel, I would think much like the feel of the EB stuff.... hhhhhmmmmm

A cursory look thru the trusty  Mouser catalog finds many throws and values of slide pots available and they all seem to be rather economical.... hhhmmmmm

Shall I continue down this road or are there major issues with slide pots that I am not aware of.....

Thanks,

Mick

Well check out how Morley did this 4 channel volume pedal that I got last week. It's all slide pot based:



I can get you some more detailed pictures if you need them but it's pretty much strings attached to both ends of the pedal pulling the pots back and forth.
Check out my metal band here: www.facebook.com/hollowshell
or
my personal effects building page here: www.facebook.com/brotronics

puretube

This thread reminds me of one of the saddest days in my life...  :icon_sad: :icon_cry:

MicFarlow77

Quote from: puretube on May 07, 2008, 07:41:23 PM
This thread reminds me of one of the saddest days in my life...  :icon_sad: :icon_cry:

I'm not sure I want to ask... but this post has my curiosity going thru the roof doode.... I hope it's not a really really sad day in a bad way type story....

John Lyons

One of the main problems with wahs is that the pots do wear out. get scratchy etc.
Slide pots in general are pretty whimpy and fail sooner than rotary pots, especially the cheaper ones.
The "good" pots are heavier duty claristat, allen and bradley and more curently speaking specially made wah pots, some with different tapers IE "Icar". Most of the old "good" pots were sealed military grade 2 watt pots.

FOr a volume pot you would want an audio taper pot and for some specialty circuits like the neovibe or tremolo you want a reverse taper, all not available in slide pots (for the most part, inexpensively that is)

I'd stick with the rotary pot mechanism.

John


Basic Audio Pedals
www.basicaudio.net/

petemoore

  To me, modern wah designs with rack & pinion were designed by Jerry the mouse in the dark ages...lack cool features, aren't DIY friendly, and look comparitely expensive to mass produce. 
  Scrap the R/P/Gear/Dshaft pot, and start the design process...and do what I did and forget about designing then machining all that..one-offs are hard to do at home..unless you're priming a pipeline of mass produced injection molded parts [in which case you'd do well to think that through real good then hire me as consultant to be sure...]
  Use photocell or other type of improved [reliability at least] sweep control.
  That said...I have two 'regular old wah's that [after re-tweeks] work great !

   
 
Convention creates following, following creates convention.

Ry

Speaking of moving out of the dark ages, I've been wanting to try out these resistive strips, but the logic behind them might get a little complicated:

http://www.sparkfun.com/commerce/categories.php?cPath=23_143

MicFarlow77

Quote from: John Lyons on May 07, 2008, 11:42:46 PM
One of the main problems with wahs is that the pots do wear out. get scratchy etc.
Slide pots in general are pretty whimpy and fail sooner than rotary pots, especially the cheaper ones.
The "good" pots are heavier duty claristat, allen and bradley and more curently speaking specially made wah pots, some with different tapers IE "Icar". Most of the old "good" pots were sealed military grade 2 watt pots.

FOr a volume pot you would want an audio taper pot and for some specialty circuits like the neovibe or tremolo you want a reverse taper, all not available in slide pots (for the most part, inexpensively that is)

I'd stick with the rotary pot mechanism.

John

Very good points John... I think I'll continue on the road I was on before... we'll see where we end up.

Quote from: petemoore on May 08, 2008, 10:52:39 AM
  To me, modern wah designs with rack & pinion were designed by Jerry the mouse in the dark ages...lack cool features, aren't DIY friendly, and look comparitely expensive to mass produce. 
  Scrap the R/P/Gear/Dshaft pot, and start the design process...and do what I did and forget about designing then machining all that..one-offs are hard to do at home..unless you're priming a pipeline of mass produced injection molded parts [in which case you'd do well to think that through real good then hire me as consultant to be sure...]
  Use photocell or other type of improved [reliability at least] sweep control.
  That said...I have two 'regular old wah's that [after re-tweeks] work great !
 

I agree that the rack and pinion system that is implemented on most wah's it very outdated and needs to be done away with. I am kinda headed down that road. However, for our purposes, I think it will be hard to get away from certian aspects of it based on what is currently available to work with, namely the many different types of pot tapers needed and the fact that what we do have available to us can be driven by a pinion or gear of some type.

I have been digging on some website looking for off-the-shelf components that can be utilized in a manner that can offer flexibility, range of motion, a smooth feel, protection from mechanically damaging the pot and design that is also quite affordabe and not too terribly time consuming to construct (I hope anyway.....)

If it works out it will be ultra flexible!

I will keep everyone posted on progress!!!!

Thanks all and please keep suggestions coming.... this is a long way from being put into stone!

Mick

puretube

Quote from: MicFarlow77 on May 07, 2008, 07:45:48 PM
Quote from: puretube on May 07, 2008, 07:41:23 PM
This thread reminds me of one of the saddest days in my life...  :icon_sad: :icon_cry:

I'm not sure I want to ask... but this post has my curiosity going thru the roof doode.... I hope it's not a really really sad day in a bad way type story....


It was a strictly On Topic sad story about Wah-casings...

puretube



puretube

No problem for a capacitance-multiplier like me...   :icon_razz:

Pedro Freitas

Quote from: petemoore on May 08, 2008, 10:52:39 AM
  To me, modern wah designs with rack & pinion were designed by Jerry the mouse in the dark ages...lack cool features, aren't DIY friendly, and look comparitely expensive to mass produce. 
  Scrap the R/P/Gear/Dshaft pot, and start the design process...and do what I did and forget about designing then machining all that..one-offs are hard to do at home..unless you're priming a pipeline of mass produced injection molded parts [in which case you'd do well to think that through real good then hire me as consultant to be sure...]
  Use photocell or other type of improved [reliability at least] sweep control.
  That said...I have two 'regular old wah's that [after re-tweeks] work great !
 

I agree that the rack and pinion system that is implemented on most wah's it very outdated and needs to be done away with. I am kinda headed down that road. However, for our purposes, I think it will be hard to get away from certian aspects of it based on what is currently available to work with, namely the many different types of pot tapers needed and the fact that what we do have available to us can be driven by a pinion or gear of some type.

I have been digging on some website looking for off-the-shelf components that can be utilized in a manner that can offer flexibility, range of motion, a smooth feel, protection from mechanically damaging the pot and design that is also quite affordabe and not too terribly time consuming to construct (I hope anyway.....)

If it works out it will be ultra flexible!

I will keep everyone posted on progress!!!!

Thanks all and please keep suggestions coming.... this is a long way from being put into stone!

Mick


Don't use a potentiometer. Go Zvex way!  :)
A wahprobe is the future. The probe translates foot movement to resistance, right?
So, to mimic a %^&*ed wah sound we have only to program a PIC to sense when one's foot is stopped anywere
the sensing area for a couple of seconds and lock that resistance reading.

Better explained:
If the foot is moving, the PIC would not lock on a resistance.
If foot stops somewhere for 2 seconds the PIC locks that resistance (and shines a cool blue LED :D )
Then the PIC would wait 2 more seconds for you to remove the foot and continue sensing.

The problem is, I don't know anything about PICs! Eheheh   :D
Can this be done?

Pedro
Please vitist: http://www.memoriar.org/

jasonsmusicgear

Quote from: MicFarlow77 on May 07, 2008, 02:21:17 PM

Also, a request for assistance. Does anyone with a Dunlop rack and pinion  and also possibly have a Gear Pitch Gage. I need to be able to confirm the pitch on the rack and pinion. Based on some preliminary calculations I have arrived at a pitch of 32, but I am not 100% for sure.

If no one has a Gear Pitch Gage to try, then at least a count of the number of teeth on the pinion. I found a pic online and counted 14, but it was not a really clear picture so I am not sure I got the actual number correct.

Also, perhaps more important... can someone measure the amount of travel the pot goes thru for a standard Dunlop system. Abraham at Dunlop thought the pot went thru about 180 degrees of travel, but that was a guess.. can anyone confirm? Also, what is the max possible travel. The Alpha pots have a 300 degree turn radius, is that similar to what the current wah pots use... I would imagine it is, but I am also not sure since I do not have any wah pots handy.

My thinking now is that if the standard wah pots have the same 300 degrees possible, then I want to see if I can get 250 - 260 degrees out of my enclosure.... we will see.. depends on the pitch and what parts can be gotten off the shelf...


I do not have a pitch gage but the pinion does have 14 teeth in my dunlop pedal.  The actual travel on mine is only about 95 to 100 degrees and the pot has a normal 300 degree possible travel. 

Also, thanks for the tip about wrapping my spool with sandpaper, it works great!
Here are some pics for you.






Jason

Pedro Freitas

One other idea that struck me.

Why not use a air-core variable capacitor. Can be home-made to fit any space or shape.
One would use the wahprobe/mxr envelope filter technologie to create an oscilator controled by the variable
cap and use its output to set a resistance value.
Heck, we can even use the 2 halves of the shell to make a giant variable cap.
Infinite shaping posibilities, no wear, simple (+/-), affordable.

Pedro
Please vitist: http://www.memoriar.org/

kurtlives

Quote from: jasonsmusicgear on May 08, 2008, 08:03:16 PM
Quote from: MicFarlow77 on May 07, 2008, 02:21:17 PM

Also, a request for assistance. Does anyone with a Dunlop rack and pinion  and also possibly have a Gear Pitch Gage. I need to be able to confirm the pitch on the rack and pinion. Based on some preliminary calculations I have arrived at a pitch of 32, but I am not 100% for sure.

If no one has a Gear Pitch Gage to try, then at least a count of the number of teeth on the pinion. I found a pic online and counted 14, but it was not a really clear picture so I am not sure I got the actual number correct.

Also, perhaps more important... can someone measure the amount of travel the pot goes thru for a standard Dunlop system. Abraham at Dunlop thought the pot went thru about 180 degrees of travel, but that was a guess.. can anyone confirm? Also, what is the max possible travel. The Alpha pots have a 300 degree turn radius, is that similar to what the current wah pots use... I would imagine it is, but I am also not sure since I do not have any wah pots handy.

My thinking now is that if the standard wah pots have the same 300 degrees possible, then I want to see if I can get 250 - 260 degrees out of my enclosure.... we will see.. depends on the pitch and what parts can be gotten off the shelf...


I do not have a pitch gage but the pinion does have 14 teeth in my dunlop pedal.  The actual travel on mine is only about 95 to 100 degrees and the pot has a normal 300 degree possible travel. 

Also, thanks for the tip about wrapping my spool with sandpaper, it works great!
Here are some pics for you.






Jason
Does anyone know where to get that little white thing that pushes on the gear?
My DIY site:
www.pdfelectronics.com

Zedmin_fx


Dragonfly

all this talk about wah pots, PICs, Probes, etc forgets one thing...

Mic isn't making a wah...he's only making an enclosure that could be used to make a wah....or a fuzz...or tremolo...or phaser...etc, etc, etc....

It makes for great discussion and idea sharing, but is beyond the realm of what Mic is looking to do. The only reason (I assume) he is asking about pots is so that he can get the angles and the attachments correct so that a pot can be used to control whatever the shell is chosen for.

IMO this type of discussion would be better in a separate thread...it will make it easier to find / search for in the future.

kurtlives

My DIY site:
www.pdfelectronics.com


kurtlives

ah Germany

Sorry to go off topic but anyone in NA have one?
My DIY site:
www.pdfelectronics.com