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DIY Stompboxes => Building your own stompbox => Topic started by: lerxst88 on August 19, 2008, 07:29:43 PM

Title: more wah progress
Post by: lerxst88 on August 19, 2008, 07:29:43 PM
ok so i built the DIY circuit tester and i found that the inductor wasnt passing signal probably because one of the legs snapped off during extraction. i unsoldered it and tried to resolder on the legs and in doing so i made the inductor into garbage. then i put a piece of wire connecting where the two legs of the inductor would go to see if it would pass signal when the wah was on. still nothing when engaged (but i do get sound when its bypassed) i went over the board again with the Circuit tester and found that my 68k resistor wasnt passing signal to the other side. any recommendations on a new inductor or a replacement for the 68K (since i think im out of them)

here is the schematic im using and how the wah is wired now
(http://i35.tinypic.com/5mwzdu.gif)
Title: Re: more wah progress
Post by: lerxst88 on August 19, 2008, 08:51:26 PM
also i wanted to mention that instead of using a proper wah inductor im going to use a mini transformer

this site said it would work: http://www.geofex.com/Article_Folders/wahpedl/wahped.htm#ryo
Title: Re: more wah progress
Post by: lerxst88 on August 20, 2008, 07:45:25 PM
any other resistors i can use aside from a 68k? any advice anyone?
Title: Re: more wah progress
Post by: omarvolta on August 20, 2008, 07:55:14 PM
you mean the 68k right?? have you measured it out of the pcb or with a leg in the air to see if it's mulfunctioning?? If you don't have anymore 68k then try adding some values in series.
Title: Re: more wah progress
Post by: lerxst88 on August 20, 2008, 08:27:15 PM
well i dont know if its working or not but i read you can replace it with a 47k and thats whats in there now. i went over it with the audio tester and it stops getting signal here. any ideas?

Title: Re: more wah progress
Post by: ubersam on August 20, 2008, 09:02:34 PM
I've used as small as a 10K resistor in place of the 68K without a problem. you said you are getting signal at the input side of the 68K/47K but not at the output side. When you're probing the circuit, are you touching the output side of the resistor at the solder joint or past the solder joint, i.e. adjacent trace or base of Q2? If you are testing for signal at the latter two points instead of the actual solder joint of the resistor, there could be a break in the trace right at the edge of the solder joint. Try testing for signal right at the solder joint.
Title: Re: more wah progress
Post by: lerxst88 on August 24, 2008, 11:11:21 PM
i tried testing it at the solder joint after and right after the resistor itself, like on the leg. still nothing. im getting a digital multi meter soon so maybe i can test this circuit and get some numerical values.