analog bit crusher

[Gibbermann]

Hi, i built the analog bit crusher, and it works only when i touch pin 3 of the upper IC, and then it seems to be working perfectly. any thoughts? i'm a bit lost... thanks!

[alex.s]

Sounds like either a cold joint or perhaps a bad IC to me?

I'd try swapping the IC (if it's socketed) and then reflowing the joints if that doesn't work, or reflow first and swap ICs later if nothing changes if you haven't socketed.

[Gibbermann]

Hey Alex,

thanks for your response! i changed the (luckily socketed) IC's, checked all the soldering and checked all the traces and cuts for accidental connection. no luck.. :( still, when i touch the ic it works. not because i press on it, but it seems that being connected to my body does the trick. so i figured i am a large resistor, and tried a 1500 ohm resistor, but thats not it. any more thoughts? thanks! :)

[Luke51411]

Is it wired up in a box with all your jacks, stomp switch etc? Do you have a multimeter to check voltages and continuity? Sounds like maybe something isn't grounded that should be... or at least that's the first thing I would check.

[SonusFluxa]

I put this together this afternoon, only to have the same problem. I noticed that it got louder when my hand touched the sleeve of the guitar input, ie ground. I tried a few things that didn't work and then started poking around with a 2.4k resistor, circuit bending style. I had one end on the bottom ground strip, and I slipped from pin 3 to the anode of the horizontal diode, which did the trick without any contact with my body. Soldered it, and now it works fine. Not the prettiest thing, but it at least got the job done. Since it's on the underside of the board, I have a piece of double sided insulating tape between the resistor and the board.

Tl;dr, got it to work with a 2.4k resistor between ground and the anode of the horizontal diode.

By the way, I'm using two TL072's, two 1N4148's, a J113, and a 1M pot. I hear a whine in the background, but it doesn't seem as pronounced as what other people have mentioned. Hope this helps!