tonepad wah debugging please

Started by jaehung105, June 08, 2010, 02:17:34 PM

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jaehung105

i built the tonepad basic wah wah circuit and i need help debugging it.

the schematic is here - http://www.tonepad.com/getFile.asp?id=114

im kinda broke so i used a Mouser 42TM013 transformer's primary coil instead of a wah inductor, which smallbearelec.com says "PC Mount, 1K to 8 ohms. The primary makes a decent, cheap 500 mh. inductor for a Wah or a Wild Mouse"

my wah pot is "The Black Bear" 100K wah pot from smallbearelec.com

i have my pot on backwards, i think, but im too lazy to change it right now in the night  :P (are the leads numbered like a normal pot?)

i shipped my amp because ima move so i used a laptop mic input with a converter and the sound recorder on the laptop to hear my guitar.

when i strum without the wah, I get my guitar signal just fine with a lot of gain.

when i strum with the wah,  i get my guitar signal without the gain, but when i rotate my wah pot, i dun get the tone shift and instead get a scraping noise on my  recording instead.

the scraping noise sounds like a switch being flipped or sumthing

is it because my pot is soldered on backwards or sumn else? how do i fix it?

thanx for the help!


ps, i live in taiwan, so buying parts is near impossible cept for the resistors, pots, and caps..

Jae

Bullet79

the inductor are backward... please check your off-board wiring too..

boogietube

Inductors have polarity? News to me. I don't think that they do. 
Electrolytic capacitors have polarity.
Transistors have pin outs. Sometimes emitter base collector -  sometimes collector base emitter.
It's probably one of these two. And, check off board wiring.
Pedals Built- Morley ABC Box, Fultone A/B Box, DIY Stompboxes True Bypass box, GGG Drop in Wah, AMZ Mosfet Boost, ROG Flipster, ROG Tonemender, Tonepad Big Muff Pi.
On the bench:  Rebote 2.5,  Dr Boogie, TS808

petemoore

  Pot backwards means toe down = bass side, wiper wire of course has to be in the middle, when the wah sounds backwards and you want toe down to = treble, swap the wiring of the outside lugs of the pot.
  Other than that it sounds like it could be a miswire of some sort.
  There's a boost stage [relatively easy, debugged when boost is produced: test with audio probe the 1rst stage.
  the 'wah' part works when everything is 'right', as in correct to the schematic...which for me boils down to measure anything that can be measured between nodes, use coded values for everything else [capacitors, inductors] that I can't measure.
 
Convention creates following, following creates convention.