Hey, I built a pedal last night....it's been a while

[Bill Bergman]

I was unhappy with the crappy wah pedals I had so I thought I'd see if my solder iron would still work to make a new wah. Didn't have any blue press-n-peel so I order a Mod-Wah pcb from GGG.(thanks JD). It sound really great....least far as I can tell by twiddling the pot by hand.(probably gonna strip my Shred-o-Matic D-1 for the shell). I'm using a TDK 48 and 1503 inductor. Anyhow I made a few observations and don't know if they have been suggested already....

1.) I only had a 4 position 3 pole rotary switch instead of the called for 3x3. Why not leave the 4th posion open, then the wah can act as a volume pedal in the 4th position insead of a wah.
2.) Why not use panel mount pots instead of trim pots. They all have very usable setting that would be worth accessing without having to open up the pedal to change.

[nightingale]

Nice to see you around again Bill,
There were some recent threads about wah transistors. I socketed the tranny's in my modded 80's dunlop, and put in some NPN's 350-400hfe and i got alot more of a sweep out of my wah with a better "sweet spot". the OG tranny's were around 650hfe..i'm alot happier with the way the mods sound now.

[Bill Bergman]

I only tried 2n5089's so far and I think they were far from being matched. I think they were several hundred HFE's apart. It sounded pretty good to me though. Do they need to be fairly close in value?

[Paul Marossy]

Well, I'm no wah expert. But, I that's one thing I like about DIY - if you want to use pots instead of trimpots, you can!  :wink:

[nightingale]

Bill,
I don't think they have to be matched. I ended up with a 400hfe inthe Q1, and around 360hfe for Q2. I was just "testing with my ears"  a small batch of 2N4401's that i had. all of my other values match up close to these: http://fuzzcentral.tripod.com/axiswah/axiswahlayout.gif

hope this helps man,

[Bill Bergman]

Thanks for the input!

[troubledtom]

it's really nice to see you back bill
         peace good health,
                 - tom pollock
ps: building 200 pedals in a yr and half will burn anyone out :shock:

[Bill Bergman]

Thanks Tom!
Though I've been lurking the whole time.

[petemoore]

Hey Bill, it's been a while, I remember you said you  were taking a break.
 Nice to see your post !!

[aron]

Cool Bill!!!!!!  

[Bill Bergman]

Yeah, I'm back, but you'll probably wish I wasn't because as usual, I have more questions than answers.

and here is some questions.....
1.)On a wah pedal do you usually try to get full rotation of the 100k pedal pot? I'm getting about 60% rotation but still sounds good.
2.)The 50k "Q" pot seems to have no effect. (This is on GGG's Mod-Wah) What exactly is "Q".

Thanks for replies......

[petemoore]

If you're getting enough treble and bass sides to the sweep...why mess with it?
 Just a not well thought out thought...but I used it on the EZVibe last night...
 Take a 250k pot and tweek it down in value using resistors from wiper to lugs 1 and 3...of course you're probably 'stuck' with 100k wah pot with gears....
 Anyway, the EZ Vibes pot is probably larger than what it needs to be, but I get easy to use [no wild jumps over the range of speed in a small part of the pots rotation] speed control over a mid section of the potshaft range [from about 1/4 CCW to 2/3rds CW takes it from whippin' fast to plenty slow]...then I just installed a limited range 'knob turner'...you may laugh but it works great, doesn't use a treadle, and I can control it easily with my right foot]...you WILL laugh, but I like it...here it is !!!
 It's just a couple zipties, clamped around the knurled [roughed up] potshaft going through a 3'' tube, just offset from the shaft...push the zipties up and the pot goes CCW, pull them down it goes CW...sweet...took about 20 minutes to implement !!! Takes the potshaft about 2/3rds of it's full travel, in this case that's 'plenty' for the speed control.
 Using the right sized zipties, they bend around and twist the potshaft, but stay straight enough at the 'push pull' end not to bend as I push them up the tube...then I tied the 'actuator' ends [push pull end] together and wrapped them in tape so I have a 'blob' that I can just push on easily with foot.
 Very Homey and quite DIY, looks funky/works great...and...was easy mechanically [no treadle is nice, low profile].
 Sorry Bill, I'm sure this is way gangly for your upscale build techniques...lol  :roll:  
 >>>The Q pot...I have the same boat...it has Very Little discernable effect on the sound at all, and was said to be dependant on working by have a 500uh inductor....the one I have that came in the VOX 847 is 600 or 700 [they say]...
 Q, IIUC is the width of the sweeped band. Wider Q means more open sound, lower [smaller freq width] means more pronounced wah....IIUC.
 GGG has the 'modwah' GEO has 'technology of the wah pedal' and theres Stuart Castledines pages...other reads too.
 I changed the transistors on my VOX 847 from the MPSA18's to different ones [sockets], there's a recent thread....I liked the lownoise highgain Q for the Gain Q, and found out that a BC109, for the sweep Q made my wah a huge amount more usable, took out the 'mids 'whip'...midrange gonk tone...and super fast sweep during the middle part of the sweep...I thought I needed an inductor [maybe that would help even more...] but this wah sounds just wonderful as it is now...for the first time...I did 'everything' modwise to it EXcept the Q swaps...and it was unusable...till I swapped that Q. 2n4401 also sounded good, the BC seems to impart a 'character' I like, possibly a light touch of    distortion.
 I felt like typing I guess....the available reads are more concise, accurate and inclusive...

[Bill Bergman]

Can you post a picture of that configuration? I'm having a liitle trouble envisioning your ziptie thingy :shock: