Wah pot tapers, more specifically CW vs CCW in crybaby shells.

Started by Myampgoesto12, January 26, 2019, 10:16:24 AM

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Myampgoesto12

I've seen in a bunch of discussions like this one:

https://www.diystompboxes.com/smfforum/index.php?topic=102233.0

Where the fact that a crybaby turns the pot CCW as you rock towards toe down is mentioned, but not elaborated on.

So let's take a Hot Potz 470k volume pot for use in the High Gain volume pedal. Heel down is less volume toe down is more volume. Given the physical rotation of the pot to create the volume swell(that is essentially turning it backwards), wouldn't this pot be a "C" taper? And why isn't this stated anywhere?

The reason I ask is mainly for this project:

https://www.diystompboxes.com/smfforum/index.php?topic=121692.0

If I were to buy an "audio" taper wah pot from anywhere that's meant to be used as a crybaby replacement pot, would that pot be a "C" or "Reverse Audio" taper to accommodate the way that the pedal actually turns the pot?

Thanks!

pinkjimiphoton

paging dr gagan, paging dr gagan....

pm joe gagan. he is THE wah master, and he has some awesome pots, including c taper for wahs that are affordable and incredible.
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Myampgoesto12

Thank you, I'll give that a shot.

You ever try an "audio taper" for a wah?

I've seen a graph plotted for the taper of a Hot Potz2 100k, strange beast.

I don't think the kink in my wah makes it unusable. But if I can get rid of it I'd like to. Hah

pinkjimiphoton

audio taper may be fine. dunno, never paid attention to it too much. i rarely use my wahs live, tend to opt for an envelope filter instead.
that said, have ya read the technology of wahs yet on geofex.com?
you can most definitely affect the sweep rather easily by changing a resistor.
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Myampgoesto12

I have, and I've modded my crybaby quite a lot.

-True bypass with buffer intact, but in effect only
-Input resistor and output transistor bias are now trimmers
-Q control pot that goes wider than stock up to 120k
-Added a cap in parallel to the range cap to make that Cantrell specs
-Cantrell toe down control(10k is all I had. Quite a range)

I haven't had a chance to try red or yellow fasels, I've read mixed info on their effect on tone after all these mods.

The quick transition in the middle range of the sweep is why I ask about audio taper. It isn't a deal breaker, every analog wah I've ever played has this. And no matter the settings use on the wah is is present, and it moves proportionately with pot adjustment.

Just seeing if anything can eliminate it.

Myampgoesto12

I'm having trouble finding a way to contact Joe Hagan, I'm not sure if he's on here or if I'm missing something with finding people on this site. I can't seem to search for users.

Any help? Thanks!

GGBB

Quote from: Myampgoesto12 on January 30, 2019, 09:09:17 AM
I'm having trouble finding a way to contact Joe Hagan, I'm not sure if he's on here or if I'm missing something with finding people on this site. I can't seem to search for users.

Any help? Thanks!

Make sure you get the name right - Joe Gagan.

If you do a Google search, you'll find his storefronts on reverb and ebay, and you can contact him there. I'm not sure if he likes being contacted directly here or not, or even if he has PMs enabled, and I don't recall his ID anyway. He is active from time to time.
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Mark Hammer

Wah pot taper is a very personal thing.  After all, the taper partly determines how the important expressive changes in filter center-frequency mesh with your ankle bones.  Your foot and ankle have to have the degree of mobility that complements where the pot does what you want.  It's not a matter of a pot taper being "wrong" or "best", but what works for you.  I suppose the footwear you use plays a role, as does the physical height of the wah when in use.  We think of it as a pedal, but it's a motor skill as well.

One of the dilemmas of wahs is that strictly linear tapers don't work so well, in terms of expressiveness.  What that means is that simply reversing the connections between the outside lugs to flip the direction of the filter sweep (lower with toe down, and higher with heel down) is largely unsatisfying for many users, if one were to use a pot with a taper optimized for traditional sweep (toe-down = higher). n There are likely electronic ways around that, but there we moved into a different topography than the classic Crybaby type.

digi2t

Quote from: Mark Hammer on January 30, 2019, 09:24:51 AM
Wah pot taper is a very personal thing.  After all, the taper partly determines how the important expressive changes in filter center-frequency mesh with your ankle bones.  Your foot and ankle have to have the degree of mobility that complements where the pot does what you want.  It's not a matter of a pot taper being "wrong" or "best", but what works for you.  I suppose the footwear you use plays a role, as does the physical height of the wah when in use.  We think of it as a pedal, but it's a motor skill as well.

One of the dilemmas of wahs is that strictly linear tapers don't work so well, in terms of expressiveness.  What that means is that simply reversing the connections between the outside lugs to flip the direction of the filter sweep (lower with toe down, and higher with heel down) is largely unsatisfying for many users, if one were to use a pot with a taper optimized for traditional sweep (toe-down = higher). n There are likely electronic ways around that, but there we moved into a different topography than the classic Crybaby type.

By Mark's definition, the true origin of the "c0cked wah" sound....



And if the perfect taper eludes you, then go high tech....



:icon_mrgreen:
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Myampgoesto12

Hmmmmhm I do like buttons..

In all fairness I love what I have, just a hotpot2 in a modded gcb95. On higher notes, the kink in the transition is the most noticeable, though I'm not usually trying to quack it up when playing that high.

Im really just curious as to the different results a different taper/manufacturer's pot could bring to the table.

I have messed around with a multifx unit that I fixed for a friend, that had a Crybaby preset available, after tinkering with the parameters a bit I was ultimately unsatisfied with the tone and operation of the unit almost entirely, except for the fact the the sweep was super smooth all the way across the treadle movement. Tonally, the toe down was weak, the heel down was dead, natural and pinch harmonics almost wouldn't come through at all, that depended on the note being played, it seemed.

I've found the Joe Gagan Wah EBay page, I'll shop around a bit and check some videos for these units in Crybabys before really jumping on it.

pinkjimiphoton

did ya do the sweep mod in rg's article?
a google search may answer some of your questions
pm me for mr gagan's email

https://www.diystompboxes.com/smfforum/index.php?topic=75945.msg619488#msg619488

http://www.wah-wah.co.uk/diy.html

https://www.diystompboxes.com/smfforum/index.php?topic=75945.msg619660#msg619660

oh @#$% it, just read the whole thread there ;) ^^^^^

you could try adding small resistances in series with the pot ya have to move where the "quack" comes in i imagine, tho i haven't messed with it.

try paralleleling resistors 1/10th or 1/100th the value of the pot between the wiper and each end and see if ya can get a taper you like out of it.

but joe has special gears that give ya a better sweep, and more of it.
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Myampgoesto12

That's the sweep cap I referred to earlier, I've read all of those before as well, they are partly how I got this far into modding/building. I have done extensive searching to the point of headaches in the past. But I worked through it and found setting I could dig.

Speaking of mods, the Vocal/Q mod really does wonders. With it at its quackiest setting that kink is really sharp, but still really only on high notes. I still play with that setting depending on how aggressive the music I'm jamming to is.

I've also read in here, some time ago that the "kink" is to be learned and gotten used to, which I have done hah.

However on RGs article it is explained the a linear pot may yield a less expressive tone, since the transition is so smooth. I get that now that I see it in words again at this point in time. Its been a while since I did any mods to this wah, little over a year.

Thanks for the input. And for your help.


pinkjimiphoton

yeah, linear is more of a tone sweep than a wah. some of the old japanese multi wah things... you know, surf, siren, hibachi's crackling, fuzz, wah (backwards) and volume (forwards) or vice versa would use them, and it wasn't a great experience to play with. back then? they were AWESOME cuz we had NOTHING...

<uphill to school 500 miles one way, every day, by cracky....>
:icon_mrgreen:

i gotta agree with our esteemed colleague, professor Hammer, and agree that its more important where ya set the "kink" to resonate with your own personal anatomy.

the vocal mod i like too, but too big and it can get weird.

am a huge believer in sacrificing the magic smoke to the fuzz gods here, and will try anything once. if i like it, maybe more.

the first pedal i ever did was my wah, with RG's most excellent long distance email support, when i first got on the web. once it was dialed in, i've never seen a reason to change anything, other than adding a b50k pot in series with the board out so i can use it in front of a fuzzface if i want to.

but i'm one of them MONSTERS and infidels who always has the fuzz first, before the wah for that mondo sqvacking most peeps find abhorent.

you would probably like the colorsound wah circuit. you don't need inductors, they give more of that kink i think than some others do.

to me tho, the best wah for huge range of tonal expression is still the ankle-busting old telray morley powerwah boosts. them suckers got some range and a good bit of intestinal fortitude!

rock on, chuck!
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"When the power of love overcomes the love of power the world will know peace."
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PRR

Quote from: digi2t on January 30, 2019, 09:37:49 AM...the true origin of the "c0cked wah" sound....

Whoa!! For a moment I thought that was your ankle monitor, so you couldn't leave your house and get in more trouble!

(Image Search finds ankle massage thingies like that.)
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Rob Strand

QuoteWhoa!! For a moment I thought that was your ankle monitor, so you couldn't leave your house and get in more trouble!

(Image Search finds ankle massage thingies like that.)

It's ransomware (ransomwear).  You have pay your bitcoins to get a code to release it  ;D


QuoteIf I were to buy an "audio" taper wah pot from anywhere that's meant to be used as a crybaby replacement pot, would that pot be a "C" or "Reverse Audio" taper to accommodate the way that the pedal actually turns the pot?
An audio taper pot is "A" taper (except for some brands).  It's the reverse of C taper.
You can change the mechanics of how the pot rotates with foot pedal to reverse the CCW and CW'ness.   A circuit requiring a C taper could use an A-taper with those changes and visa-versa.    There's two ways to flip the pot directions one is to move the pot mount left/right.  The other is to change the way the lever couples to the shaft  top/bottom.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Elektrojänis

The pot in standard wah is used as voltage divider... How about using bigger value pot and a tapering resistor like suggested here: http://sound.whsites.net/pots.htm#chg-law

The kink could well happen just because that's the spot where the resistance track in the pot changes to another type (a common way to make different tapers as a smooth transition would be too expensive to manufacture).

pinkjimiphoton

the "kink" is the resonant frequency peak of the filter. remember, its just a bandpass filter for the midrange swept by foot, really. if ya take it away, no wah wah. just a mid sweep which isn't anywhere near as fun.
but yes, a bigger pot and tapering resistors could indeed be done, in theory, but in practice ya usually end up with a very weird taper, in some cases more of a switch than a pot.
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Elektrojänis

Quote from: pinkjimiphoton on January 31, 2019, 09:17:13 AM
the "kink" is the resonant frequency peak of the filter. remember, its just a bandpass filter for the midrange swept by foot, really. if ya take it away, no wah wah.

Yeah... I know... I just intepreted it wrong... I thougt that the op meant that the speed of the movement of that resonance changes at some part of the pot's rotation. (Because different tapers were mentioned too... and "kink in the transition" and talk about smoothness of the sweep...)

pinkjimiphoton

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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
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Myampgoesto12

Hah I've got a ways to go before I tear into the wonderful world of wah pots! I am really intrigued with Gagan's offerings though.

Since this has become a bit more of a wah topic than what I inended, I have a minor question regarding the input cap.

As mentioned, I have done the true bypass mod by lifting the input side of the capacitor and soldering my "effect in" wire directly to it, thus leaving the entire buffer in the signal path of the effect. I chose this way to avoid cutting the trace, have fewer things to solder/desolder, and I heard a comparison video(who's variables in the recording process could be wild...) that convinced me to leave the buffer intact.

In the geo article it is mentioned that raising the input cap (of the simple wah circuit cited above the statement) more low frequencies are allowed in. However the circuit shown does not have a buffer.

My question is this: since the buffer has an input cap .01uf, will changing the cap before the filter section change anything at all? Sorry to ask for such specific info..I'm just not knowlegable enough, and I haven't found enough info on how the cap in the buffer can restrict frequencies.

I have done the gain mod, but that can get pretty hairy so its set just a bit hotter than stock.