Need some help with an auto wah build!

[Dom D]

Hi, I'm building a Snow White Auto Wah according to Harald Sabro's vero layout. I was originally getting no wah signal at all, only a clean signal with minor changes while sweeping the pots, however, now I am only getting sound when I press down on the IC. Is the socket bad? I see nothing wrong with the soldering. I have a multimeter, but the only battery I have right now is what is powering the pedal  Does this ring a bell for anyone?

[.Mike]

I had the exact same experience while converting a Crybaby into an auto-Crybaby.

Effect didn't work. Pressed the IC. Effect worked. Let go of the IC. Effect didn't work.

I took out the socket and soldered the IC directly. Problem solved.

Mike

[Mark Hammer]

If you are gentle, you can sometimes improve the contact between socket and IC pins by tinning those pins a bit.  "Gentle" means you make sure the pins are scraped clean first so that the solder flows quickly and you don't have to apply much heat for too long.  It also means you do a couple pins, and wait for a bit for the chip to cool down before doing a few more.

Or, you can remove the socket and install a better one.

Or you can solder the chip to the board.

[Dom D]

Thank you for the suggestions. I've replaced the socket, and although I'm getting sound, it's only a clean signal with no wah. Any more ideas?

[reverberation66]

so , were you getting the wah sound before when you pressed down on the ic?  that's what I got from your original post. 

[pinkjimiphoton]

sounds just like the bassballs problem i was having.

try and get some sockets with round holes...the "flea clip" cheaper ones like ya can get at tayda pretty much suck. the round ones hold the pins a little titer in my opinion.

next, try a different chip. if you replace the socket and still no sound, and replacing the chip doesn't work,

make an audio probe. i used a 100u electro with the - end connected to the center conductor of a hunk of recycled guitar cord.attach the shield to a hunk of wire, and put a roach clip on the end of it.  plug the 1/4 inch plug into a small amp. connect the shield/ clip on a ground point, and use the free end (+ ) to probe each connection. you'll hear whatever you're inputting at each connection as you work thru the schematic. when you suddenly don't pass signal any more, that's somewhere connected to your problem.

if you're STILL stuck, do it backwards.

plug the effect output into your amp.

reverse the audio probe, and use it to INJECT signal into the circuit. in this case, start at the output jack, and work your way towards the input jack. when ya find the dead spot or zone, you just isolated your problem.

works great.

also check for microphonic parts...if anything goes "ping" when you touch it, odds are the solder joint is bad...don't just reheat and reflow, get the old solder out of there and make a good joint.

good luck mate!

[Dom D]

Audio probe sounds like something I should have. Going to try it out on monday because I'm stuck at work all weekend. Thanks sincerely for all the input everyone.

[pinkjimiphoton]

highly reccomend building two, that way you can have them for both uses on hand.