The Most Expressive Wah I Have Played...

[MohiZ]

OK, it is a lot smoother than the CryBaby graph, and doesn't tail off as sharply as I though it would. Mind you, the extra throw on the treadle compared with the Crybaby provides for finer control.

As a nerdy sidenote, it's actually one half of a sinewave (well pretty close anyway), because of the way the mechanism turns the pot. And 16,5 degrees is quite a lot more than a Crybaby - even with the bumpers removed, allowing for a lot wider throw, the crybaby's rocker only moves about 14 degrees from heel to toe! You might think two and a half degrees wouldn't make much of a difference, but that's noticeable compared to 14 degrees. A stock crybaby might have, maybe,  10 degrees of treadle throw.

[Paul Marossy]

Wow, you guys have been busy since I was here last!  I like how you guys have really dived into this topic, and I think we all learned a lot in this discussion. I don't know why, but I have become really fascinated with wah circuits in particular, they are just very interesting. 

Just keep in mind that my AutoCAD drawing might be off a little bit in function compared to real life. I think the pot rotates about 130 degrees, but it might be closer to 125 degrees or something a little bit beyond that. It's definitely at least 130 degrees when it actuates the bypass switch.

I uploaded a quickie soundclip I made this morning using my SpankenStrat thru the Colorsound wah into my Zoom 9030 effects unit with my own started from scratch customized preset. I am using primarily the mid & neck pickups (Fender "Hot Noiseless" pickups designed for Jeff Beck), but I switch the pickups here & there and some of it it also using the DiMarzio FRED humbucker on the bridge. It starts out in bypass mode and then goes into wah mode and stays there. I tried to do some different styles of music on different places on the neck to take it for a good test drive for y'all. I'm still learning how to use the thing as a small amount of movement on the treadle can really change the sound very quickly!

Anyhow, here it is: http://www.diyguitarist.com/Sounds/ColorsoundWah.mp3

[tackleberry]

The treadle sweep of stock crybabies is pretty small. Not sure why they put such thick bumpers in em. Shaving em down so theres just enough to keep it from metal to metal at each end adds quite a bit of travel. Ive also put a momentary switch in the treadle of mine as the bypass switch and eliminated the regular one under the toe end this adds some to the travel as you can push it down to almost metal to metal without turning it on or off. Plus all I have to do is step on it for it to work and take my foot off to turn it off. Course you cant leave it in a position as a filter and go somewhere else while playing. But this thread has been very informative. I have 3 empty housings to mess with. Im gonna have a stock 1 and have 2 more for various mods. Much easier to hear the difference on the fly. Waiting on my order form mouser to get here. Got 5 of the eleca inductors from smallbear to mess with in my modded pedals. Also a stock dunlop wah pot, a hot potz and a ICAR to see which I like the best.

[leeyoungun]

The Colorsounds give you more control of the sweep with that wide treadle range, but I agree with the "it's in the circuit" camp. I have a rare 800mH inductor Colorsound and a RMC Wheels Of Fire and the RMC pretty much nails it tonally even with the narrower physical sweep.

[Pedal love]

Paul that thing is like Whaaa! I think you are on to something keep the wah output but get the feel for the control more- but that really reaches out and grabs you by the neck! Very cool.

[Paul Marossy]

Paul that thing is like Whaaa! I think you are on to something keep the wah output but get the feel for the control more- but that really reaches out and grabs you by the neck! Very cool.

Yeah, it's kind of cool, huh? I like how it gets real synthy sounding about 60 seconds into the soundclip, it's an interesting effect.

If I play it for a while, I can use it pretty well. It's a bit hard to get it to sound just right when I first sit down to play it, though. I guess it's just a matter of getting used to it like I have done with all the other ones I play more than occassionally.

[juse]

Once again, this is an excellent thread. It's got me thinking... I have a wah I'm building right now using a CB shell, and I'm going to modify the treadle to give it a longer throw:



Maybe it will get me in the Colorsound ballpark 

[Paul Marossy]

Once again, this is an excellent thread. It's got me thinking... I have a wah I'm building right now using a CB shell, and I'm going to modify the treadle to give it a longer throw:



Maybe it will get me in the Colorsound ballpark 

Hey, before you do that, make sure that it won't exceed the travel allowed by your gear. I think the rack might go past the gear and come out when in heel down position...

[juse]

Yeah, I thought of that. I'll have to make a new rack gear for it to get the full travel. I was also going to put an adjustable bolt/nut/nut bumper setup to finetune the throw.

[Paul Marossy]

Yeah, I thought of that. I'll have to make a new rack gear for it to get the full travel. I was also going to put an adjustable bolt/nut/nut bumper setup to finetune the throw.

Sounds like you have it all under control...

[R O Tiree]

The other thing to bear in mind is, go have a look at that graph I posted a page or so ago about Resistance vs Pot Angle fot a Hot Potz II pot. There's a huge region in the heel down region where it goes to about 100 ohms and doesn't change at all. Pointless, perhaps, to shave a huge chunk off the back of the treadle only to find that, by the time your foot gets that far back, it's not actually doing anything anyway.

[MohiZ]

He could always use some other pot than the Hot Potz... But anyway, all you need to do on a crybaby is take off the rubber bumpers and the mechanism'll turn the pot 270 degrees. That's the full range of your average pot. No need to shave off material.. unless, of course, you're going to modify the mechanism as juse evidently is going to do..

[R O Tiree]

Thanks, Mohiz - that has sparked off another train of thought...

So, taking the bumper off will give 270 degrees of rotation. The Hot Potz II has a total of 315 degrees. Take off 25 degrees or so (from the setup procedure, which stops you breaking the CCW end-stop of the pot when you depress the toe switch) and that leaves only 20 degrees remaining at the heel end. Anyone want to bet that Dunlop took account of this when designing the spec for the Hot Potz? "Ooh, I wonder if people will take the back bumper out to get more travel?"... "Probably - we'd better give them another 20 degree buffer, then."

The most common commercially available pots are probably those with 300 degree travel. Some are only 270 (Colorsound pot anyone?). Let's compare the rotational stop strength of a typical Alpha pot, for example, at around 5kgfcm, with what you can apply with your foot... That's a 5kg weight on a 1cm lever arm, or a 1kg weight on a 5cm lever arm. It's about 5cm from the axle to the back of the treadle, and the rack is about 10 cm forward of the axle, which is a 1:2 mech adv, so we could put a >2kg weight on the back of the treadle and the end-stop would break. How much torque do you think your foot can apply to that end-stop?

The more I think about this, the more convinced I am that the gearing and geometry of the Crybaby shell was done for very good reasons. And it's built like a tank to deter the casual optimist with a Dremel from hacking it about and breaking stuff.

[MohiZ]

That's probably true.  I was talking about taking both the front and the back bumpers away. The 270 degrees was an estimate (about 2/3 of a full circle is what it looks like), though it's probably not too far off. Anyway that's the range of the pot that's currently inside my Crybaby (I checked - in the extreme positions the mechanism is resting against the pot's end-stops - can you imagine the range is JUST right for it ). It's not a stock pot so I can't say if the one originally in there had a different range.

[Paul Marossy]

Just a suggestion for those thinking of modifying their CryBaby shell to make it more like a Colorsound wah in terms of function:

If you want to avoid any hassles with the weird taper on the Hot Potz II, just use a regular Alpha 100K linear pot instead. Sure, it won't last as long, but a replacement is only $3 at RadioShack and we all know how to solder here... so replacing it after it wears out is relatively easy. 

[juse]

Thanks, Mohiz - that has sparked off another train of thought...

So, taking the bumper off will give 270 degrees of rotation. The Hot Potz II has a total of 315 degrees. Take off 25 degrees or so (from the setup procedure, which stops you breaking the CCW end-stop of the pot when you depress the toe switch) and that leaves only 20 degrees remaining at the heel end. Anyone want to bet that Dunlop took account of this when designing the spec for the Hot Potz? "Ooh, I wonder if people will take the back bumper out to get more travel?"... "Probably - we'd better give them another 20 degree buffer, then."

The most common commercially available pots are probably those with 300 degree travel. Some are only 270 (Colorsound pot anyone?). Let's compare the rotational stop strength of a typical Alpha pot, for example, at around 5kgfcm, with what you can apply with your foot... That's a 5kg weight on a 1cm lever arm, or a 1kg weight on a 5cm lever arm. It's about 5cm from the axle to the back of the treadle, and the rack is about 10 cm forward of the axle, which is a 1:2 mech adv, so we could put a >2kg weight on the back of the treadle and the end-stop would break. How much torque do you think your foot can apply to that end-stop?

The more I think about this, the more convinced I am that the gearing and geometry of the Crybaby shell was done for very good reasons. And it's built like a tank to deter the casual optimist with a Dremel from hacking it about and breaking stuff.

What about these pots? These are what I'll be using. Any specs on them?









I was going to put an adjustable stop to fine tune the throw after I chopped it. Are you saying that I'm wasting my time?

[Paul Marossy]

What about these pots? These are what I'll be using. Any specs on them?

I assume that they are they the same thing as the Hot Potz IIs, taperwise.

[juse]

Right you are, R O Tiree & Paul ..... on a HotPotz-II there is 315° of travel, and I measured the same for a HotPotz-1. I measured the degree of travel with the stock rack gear and after full extension there are 3 teeth's worth of travel left in the pot rotation, or about 45°.






At first I thought this was a major amount of wasted potential, I mean, that's 1/8 of the total amount. But, like you said, after factoring in the buffer needed to keep from snapping the post off of the pot in either direction, that leaves me about 1 extra tooth's worth of travel to somehow magically make this a fire-breathing deep-chested monster. But, I'm thinking the CB is about right the way it is as well. Good call. I'll put up my chop saw......... (I will be leaving the bumpers off, though  )

[MohiZ]

The sweep range might be easier to control, though, if you had a longer throw on the treadle. Even with the bumpers off the Colorsound seems to have a lot longer throw than the Crybaby. The Crybaby circuit can be modified to give a wider sweep, or you could just stick a Colorsound circuit inside. As of now I think, because the range is shallower on the Crybaby, they've also made the treadle move less to make it easier on your foot.

[Paul Marossy]

I think that the Colorsound inductor wah also makes for a nice "Q-filter" sound. I am playing it mostly that way on the first tune called "The Journey" on the player here: http://improvisingguitarists.ning.com/profile/PaulMarossy

I think it will sound real nice when I get the keys and real drums added to it.

EDIT: Also, I think the suggestion that the distortion from Q1 being part of why I like this particular wah might have some validity. I haven't looked at it with a scope yet (argh! only so much time in a day), but with a clean guitar sound, I can hear that it is kind of mildly boosting the signal with I think a slight bit of distortion.