Real McCoy Wah

[lowell]

So the pot in this wah is scratchy and I want to replace it. I've cleaned it and everything but that's not doing the trick. The thing is when I went to check the value and taper I found that it was about 470k from one end to another, but if I measured from the middle to either lug I got values up to about 6M in the middle. I plan to order a hotpotz replacement which is 470k but the pot that was in the pedal was a RMC pot and I wanted to make sure first it wasn't some odd custom taper. Has anyone ever heard of this?

[guitician]

Most Wah's use a custom taper of some type. Did you contact RMC to see if they will sell a replacement?

[lowell]

Yes, and the guys was a HUGE jerk on the phone. Basically, aside from his awful attitude on the phone he refused to supply us w/ the value of the pot in his wahs and said he'd only help if it was sent to him to fix.

[guitician]

Try the Hotpotz. I put a 100k in my vintage crybaby and it works fine.

[Enzo]

No taper in the world for a 470k pot will have 6M in the center. DISCONNECT the wires and measure the resistance across the end legs. That is the pot value. Now the residual voltages and parallel components won;t confuse your meter.

I'd have to suspect any tapers they used in the real McCoy are not very different from the tapers used in all the other wah pedals out there.

[lowell]

ok thanks guys, forgot to mention that the RMC pot was measuring very weird and thus we are trying to replace it... it's also scratchy. It measures up to about 10meg as you turn it up then the resistance starts going the other way if you continue to the end!

[billyz]

I don't know if this applies but. I just took apart an original ICAR pot that had gotten scratchy. I had sprayed it with Deoxit and B5. It would work fine for a few days them back to the scratchiness. As you know these are the POTS. So , I took it apart. Pretty easy to do. MAN, they are made way better than anything going today. Anyway, it had alot of grunge built up, dual wipers and a commutator ring on top too. I used some fine sand paper and Qtips to gently polish the contact surfaces top and bottom. Then I re tensioned the wipers, just a little. put it back together and WHA LHA. no more scratchiness. I did not even use the Deoxit. Sounds great, The value did not change, actually just making better contact throughout it's range.

[noelgrassy]

From Teese (RMC) on getting that ICAR taper with a common pot;
Place a 330n cap in place of the cap(220n) that connects directly to the wiper of the pot and this will give you a near perfect approximation of the ICAR pot. The full text is at the bottom of the attached chart!

Yeah, Teese claimed to have custom tapers made for his wahs at one time but has since stopped using them in favor of something very typical and readily available to all.

You might try contacting Mike at Fulltone who sells his custom taper pots if you don't like the sound of the above mod. But nearly every wah I repair I recommend this mod and I can count the clients on one hand that have asked me to return their wah to stock.

From the chart below, you can see that 100K is the most common value pot used in Wah Wahs period.


Have fun,
Noel Grassy.

[Bloodbath]

Replace it with a 100k ICAR taper pot. If you need help finding one, let me know. I will point you in the right direction.

[Guitarist]

Regarding the taper, I tried a 470K resistor from wiper to Hot and it made an improvement here.

I'd like to measurements across an ICAR pot to see the rates of change. Then maybe others could be scraped/shaped.

Taking a bad pot apart and fixing it can do wonders.

[noelgrassy]

The mod I suggested really works to get that early "Clyde" tone. It really
did come from Tease too. The cap to change is labeled Cef in the schem I
provided. Any film type will do, although I prefer the Polypropylene caps in a typical wah wah.
Just spring for the pot offered by bloodbath if you're unsure of the components in a wah.
Dude, "scraped & shaped"? How does one change the pot's taper by destroying the thin deposit of carbon?
You're just foolin' right?

NG.

[Shea]

Dude, "scraped & shaped"? How does one change the pot's taper by destroying the thin deposit of carbon?

To increase resistance at a given spot, you scrape off a tiny bit of carbon from the edge of the resistive element using a pen knife. To decrease resistance, you take a pencil and add a little graphite at the edge of the element. I've done that to balance a dual-ganged pot that I used for a post-phase inverter master volume. It made the tone a little less fizzy at low volumes.

[HTH]

Yes, and the guys was a HUGE jerk on the phone. Basically, aside from his awful attitude on the phone he refused to supply us w/ the value of the pot in his wahs and said he'd only help if it was sent to him to fix.

I used to own an RMC3 and still have the spare pots here - they're 100k just like any other wah pot. I seem to recall that those same pots he was having made with the custom taper started to get sold to anyone who wanted to order them which I don't think he was very happy about.

Anyway, the RMC3 was a great pedal (I got mine back in 2000, maybe even a couple of years earlier). otoh, I had a RMC Joe Walsh signature pedal here recently that was really uninspiring - my friend sold it after a week and went back to his Jen Crybaby that I modded.

Back to the pots... look for those Rocpots/Propots - I've used them a few times and they're just the same as the old pots imo (or close enough to make it not worth worrying about)...

ICAR Taper 100K Wah Pot, Fits: Vox, Crybaby, Fulltone, - eBay (item 300384703693 end time Feb-06-10 11:48:19 PST)

[dumbassbob]

Good info Here

[ronh]

I tried this in my new GCB-95 Crybaby. I like it. Sounds better to my ears than stock,
its cheap, works and is reverseable.