Wah Modding Questions

[tehfunk]

A couple of questions here that I've formulated after doing a pretty good amount of research on the different changes that occur tonally with different changes in components on the typical Vox/Dunlop circuit, in this case I am referring to the Vox V847.

1) I am aware that this is a partly opinionated question, but what do you guys think is the best reproduction icar pot?

2) For the Q resistor that a lot of people change from 33k to 47k or to 68k, would it be smart to use a trim pot, if so what value trim pot would you use. Are there any disadvantages to using trim pots?

3) I've been reading lots about impedances and all and the conflict with wahs and fuzzes and all, but I still don't really get it. So, here's my question, I know that a lot of people use an output buffer in order for their wah to work better with their fuzz if their wah is before their fuzz. But, if I wanted to put fuzz before wah, would this situation also "require" a buffer, but instead an input buffer. Basically do the same impedance problems occur in fuzz before wah situation as in wah before fuzz.

4)What is the best buffer and why?

Thank you.

P.S. If anyone would like to further enlighten me on the whole impedance issue, I'd appreciate, I've read most of the articles about it and I just can't grasp it, maybe they go to much in depth.

[tehfunk]

anybody?

[krhnyc]

A couple of questions here that I've formulated after doing a pretty good amount of research on the different changes that occur tonally with different changes in components on the typical Vox/Dunlop circuit, in this case I am referring to the Vox V847.

1) I am aware that this is a partly opinionated question, but what do you guys think is the best reproduction icar pot?

I spoke to Geoff Teese personally the other day and he recommends the Fulltone pot for a vintage wah. He said otherwise that the dunlop hot potz II is excellent. The hot potz II has a different sweep, but excellent frequency response and durability. The Fulltones are available for $25. from http://www.tone-man.com/effects.htm.

2) For the Q resistor that a lot of people change from 33k to 47k or to 68k, would it be smart to use a trim pot, if so what value trim pot would you use. Are there any disadvantages to using trim pots?

You could you a 100K trimmer. Pre measure it for 33K and mark it so you can get back to "stock". The "Q" sweep is not as drastic as people seem to thing. More of a subtle peak change.

3) I've been reading lots about impedances and all and the conflict with wahs and fuzzes and all, but I still don't really get it. So, here's my question, I know that a lot of people use an output buffer in order for their wah to work better with their fuzz if their wah is before their fuzz. But, if I wanted to put fuzz before wah, would this situation also "require" a buffer, but instead an input buffer. Basically do the same impedance problems occur in fuzz before wah situation as in wah before fuzz.

Buffers are necessary with old fuzzes because with out you will get oscillation. Basically a siren howl that changes pitch with the wah sweep. Fun, but not the most usable. Un-buffered wahs with high gain amps lose bottom and depth. You just can't seem to use the range of the wah.

Using a buffered output corrects this with 2 possible disadvantages.
1). some of those old school (read:cool) sounds are lost. Your heroes did it with an unbuffered wah, dig?
2) a buffer does add more current draw, less battery life.

4)What is the best buffer and why?

Buffers are pretty easy to build, find on on geofex and go for it.... or... get the foxrox FWR buffer. $45. clams, totally reversible, adjust gain, easy install. This comes stock on Teese's wahs.

Thank you.

P.S. If anyone would like to further enlighten me on the whole impedance issue, I'd appreciate, I've read most of the articles about it and I just can't grasp it, maybe they go to much in depth.

[tehfunk]

Thank you for those answers, very helpful. Yeah, I was considering a fulltone pot, but I read in a few places that people put them in their wahs and it made them sound dead and weak... So, when you say "he recommends the Fulltone pot for a vintage wah", are you implying that if I was modding a V847 that it would not be a good idea to get the fulltone pot?

Also still looking for answers to the question of fuzz before wah; does it 'require' a buffer in the same way that wah before fuzz does because of impedence issues?

Also, one question I forgot to ask, what do you guys like for repro halo inductors? How are the fulltones and whipples?

[krhnyc]

Thank you for those answers, very helpful. Yeah, I was considering a fulltone pot, but I read in a few places that people put them in their wahs and it made them sound dead and weak... So, when you say "he recommends the Fulltone pot for a vintage wah", are you implying that if I was modding a V847 that it would not be a good idea to get the fulltone pot?

Also still looking for answers to the question of fuzz before wah; does it 'require' a buffer in the same way that wah before fuzz does because of impedence issues?

Also, one question I forgot to ask, what do you guys like for repro halo inductors? How are the fulltones and whipples?

Haven't heard about any problems running a fuzz in front of the wah... except the exaggerated "wakka-wakka" sound. As far as the to "fulltone, or not to fulltone" question, I think what he was saying is that the fulltone is closest to an old pot so it will make your old pedal sound as it was intended. Newer pots aren't better or worse, just different. As new pots go, he reccomends the hot potz II. I have these brand new for $20 (S&H incl to the lower 48).

Inductors, haven't heard the fulltone or whipple.... I heard the fasel reissues... they aren't bad. I like the yellow, though the red is ok too, more of a rock sound. The thing is, the inductor is only a part of your wahs sound.

[tehfunk]

i forgot to say this before, but nice setup/collection of gear. Anyway, I was wondering have you heard the fulltone in a newer wah? What did you think? Still, looking for more opinions on my other questions... Thanks!

[krhnyc]

Haven't heard the fulltone in a newer or older wah. My '68 has a Teese pot. These are no longer available. He suggested the Fulltone for when his buys the farm. I haven't ever played any fulltone stuff. I know it gets good reviews, though honestly... I like my Easyvibes' sound more than the clips on the fulltone site for the DejaVibe. The one I built nails the "Breathe/Machine Gun/Too rolling stones/Cold Shot" sound... I'm not kidding... lucky I guess.

[tcobretti]

If memory serves the Q resistor was omitted in the earliest wah designs and in the patent, so you can use any value pot above 100k.  I think you certainly will hear the difference between smaller and greater values there, and using a 200k-500k pot is not unreasonable.

One last tip is that Teese recommends changing one of the caps to simulate a ICAR taper, but I honestly don't remember the details - go to my layout gallery and check out the Wah Comparison Chart for more info.

[tehfunk]

yeah, thats why i plan on getting an icar repro like a fulltone or whatever... But yeah I just want to hear everyone's opinions.

[azrael]

I'm using a 200K Black Bear pot from pedalpartplus.com, I believe. Sounds nice and smooth.

Also using the Whipple - sounds great! Really nice vomit-y wah tone.

[tehfunk]

cool, yeah I was wondering how the whipple compares to other inductors especially, whipple vs. fulltone inductor. what pedal are you using?

[azrael]

It WAS a Dunlop GCB-95.

I etched a new board, and am currently using that. Essentially the same "Crybaby" circuit, with trimpots in the right places so I could tweak it to taste.

I've never tried the Fulltone inductor of the Dunlop Fasel reissues, but I like the whipple way better than stock, and I think it sounds better than the GCB-95 + Red Fasel that my co-guitarist has.

[tehfunk]

okay, thanks. does anyone else have anything else interesting to add?

[azrael]

Use trimpots, fo sho.

[tehfunk]

what resistors do you suggest I use trimpots for ?

[azrael]

Vocal resistor (33K in paralle with inductor) - use a 100K trimpot, the gain/bass resistor - I think it's 470 ohm, use a 1 K, the volume resistor 68K(since you'll be converting to TB, there'll be a small volume drop) - use a 100K, the midrange resistor should be a 1.5K...replace that with a 5K trimpot, but I wouldn't adjust it past 2.7K.

[ayayay!]

okay, thanks. does anyone else have anything else interesting to add?

-posted by tehfunk


I have something to add.  Change your freaking avatar!  Everyone at work thinks I'm on a forum for gays.

[axg20202]

You may already be aware of all this, but if you're building a new wah PCB from scratch, you could do worse than check out the 'buffered wah' layout at tonepad, which has the option to leave as stock (unbuffered) or add either in or out buffers or both, all on one PCB. Footprint and drill holes will fit your existing wah shell.

http://www.tonepad.com/project.asp?id=29

Also, check out the GGG modable wah PCB:

http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=53&Itemid=26


FWIW, I built the tonepad layout with both buffers and used a Whipple. Sounds good, but thats just my opinion. To be honest, as noted on the GEO technology of the wah page, I think the PCB component values you use are more critical than the inductor as long as the inductor is in the ballpark of 400mH to 600mH.

http://www.geofex.com/Article_Folders/wahpedl/wahped.htm

[ayayay!]

Thanks man. 

[tehfunk]

Thanks man. 

lol, you're welcome, same guy though... Anyway, I received my v847 in the mail yesterday, like it, and see the shrill high end people speak of, and see the room for improvement. As I do the upgrades I am thinking of doing simple recordings that show the tonal changes. I'll post up when I am done.