2 wah pots comparsion

[yeeshkul]

I built 2 identical 60's style wah pedals. Both with The Whipple inductor. The only difference was the wah pot.
For the first unit i used the "Black Bear" 100k ICAR pot (you can get the same one at the Whipple eBay store) and Dunlop Hot Potz II ECB24B 100k for the second one. There was audible difference between those two - Hot Potz comes out sweeter, with more prominent wah sound. Quite a surprise . I am getting one for myself sooooon. For 10 bucks extra you can get real improvement.

Also i installed a switch for the range cap 10n/22n and Hot Potz with 22n cap sounds unbelievable "quacky" - almost like EH Doctor Q.

[birt]

i always use these: http://www.banzaieffects.com/ProPot-Deluxe-100k-Potentiometer-pr-20272.html

makes a standard dunlop wah sound A LOT better. with a much bigger sweep.

since the standard is a Hot Potz, i don't buy Hot Potz anymore.

[yeeshkul]

hmmm, this ICAR looks identical to the one i use. Does it have any label? I can just see two silver washers and one black lock washer, golden thread part ... is there any difference between Hot Potz and Hot Potz II? Because HPII sounds really better(longer sweep) than the common ICAR pot i usually buy.

Do you have one at hand? Could you measure the thread part lenght? It seems to be a bit shorter on the Banzai type... i don't wanna spend money on another of those (i have some spare ones now i guess )

By the way i was talking about this Hot Potz II http://www.smallbearelec.com/Detail.bok?no=364. Sounds brilliant. Did you compare this very type to the Banzai ICAR? I made straight comparsion, unit by unit with http://www.smallbearelec.com/Detail.bok?no=582 and Dunlop came out way better.

[John Lyons]

Did you try both pots in the same circuit?
Perhaps even though the circuits are identical they sound different,
different Hfe for the transistorsslight cap/resistor values etc?

John

[kurtlives]

Were the pots indexed the same way?

[yeeshkul]

Did you try both pots in the same circuit?
Perhaps even though the circuits are identical they sound different,
different Hfe for the transistorsslight cap/resistor values etc?

They are twins:
- the same board
- the same caps & res.
- the same Q1 trannies (Hfe 320, 327)
- a bit different Hfe of Q2 (400, 600) but that should behave the same way
- my Whipple is grey painted, his is golden
- my unit has 10n range cap, his unit has a selector 10n/22n - but i used 10n for all the testing
that's it

The inductor value doesn't have any impact on the lenght of the sweep ... right? I didn't measure the inductor values, i just believe he makes them about the same.

ICARs were in my favour(for no reason actually, i have never compared them untill now) and that's why it should not be kind of a psychosomatic illusion: i wish it was -> it is.

Were the pots indexed the same way?

kurt i dont understand what you mean here

I will swap the pots today. Also i will make some soundsamples and you guys can judge.

[kurtlives]

Since the pots don't use all of their rotation when you put them in you can tweak which part of the pot taper they use. There are sounds that a wah but just never makes cause the wah dosent go so far.

[John Lyons]

Ok, yeah a sound clip would be nice.

What kurt is saying is that the pots can be intalled so the wiper rotates all the way to the top or you can rotate the pot so that the wiper old goes part of the way to the top. Example If you have a problem with the toe down settings being too sharp sounding, you can back off the rotation of the post so it does not go all the way forward at tow down. You are just changing the position of the pot relative to the enclosure.

The reason I am skeptical is because the pot only changes the sweep of the wah.
The amount of wah you get aren't dictated by the pot.
The pot just the sets the "feel" or sweep of the front to back rotation of the wah.

john

[Gus]

Get two cheap plastic protractors.

Glue then together in a circle matching 0 and 180 degrees.

Drill a mounting hole for the pots in the middle.

Install a knob with a long pointer that reaches the markings on the protractor.

Mount the pot to the protractor

Turn the knob full counterclockwise

Adjust the shaft and knob at say 0 degrees

Now using a DMM set to ohms with the pot out of circuit measure the wiper to each end resistance at different degree settings.  This will show the taper of the different pots and will help find the different resistive tracts inside the pots meet to form the overall taper

Using this information you might be able to adjust how the different pots are mounted in a wha for the sweep you want

[yeeshkul]

Strange things are happening. I left the wah units behind for two days and today i tested them again. Well, i can't hear the difference anymore.
Here is the soundsample - first ICAR then Hot Potz II :

http://www.hoho.cz/osobni/ICAR-HotPotzII.mp3

[John Lyons]

I can't hear a difference from the sound clip.
After not playing them for two days and they sound the same then I'd
just go with the fact that the really DO sound the same.
The mind plays tricks on you.

Get someone to switch them out for you while blindfolded and see if you can hear a difference.

john

[Paul Marossy]

Strange things are happening. I left the wah units behind for two days and today i tested them again. Well, i can't hear the difference anymore.

Good example of pyschoacoustics in action. Funny how our preconcieved notions shape what we want to hear or what we think we are hearing, isn't it? 

[yeeshkul]

It is! . And how sneaky it is - ithe last thing i was eager to hear wast Hot Potz II working better than ICAR.
Paul, i saw on your great site that you built Boomerang. Does it sound different to VOX-type wah?

[FuzzAldrin]

I think the second one sounds nicer towards the end of the sweep!

[killerkev]

I agree. the second part sounds like a slighty higher tone at the end of the sweep. Maybe the Hotpotz is slightly adjusted compared to the other.

[yeeshkul]

Both were adjusted the exactly same way - completely to the high end.