weird buzzing sound in LPB-1 clone

[Mr. D]

Hi, i'm new to the board so please forgive any mistakes i may make in posting this. My friends and i have been following this schematic for an LPB-1:
http://aronnelson.com/gallery/album150/EH_LPB_PERF_LAYOUT

i did substitute a 820k resistor for the listed 830k resistor. also, i wired this circuit to a 3dpt switch and installed an LED also.

My problem is this: it was working perfectly once we got everything wired correctly. but after we closed the box up, the effect now makes a strange buzzing/crackling sound when i strum the guitar hard. one second it was fine, then it sounded like crap. it's so close to working right and we feel like we checked everything. could anyone please shed some light on this?

alex

[petemoore]

My problem is this: it was working perfectly once we got everything wired correctly. but after we closed the box up, the effect now makes a strange buzzing/crackling sound when i strum the guitar hard. one second it was fine, then it sounded like crap. it's so close to working right and we feel like we checked everything. could anyone please shed some light on this?
  Based on stats it's a 90% that somethings touching the box, which should touch ground.
  Push gently around the circuit wires, pull the board, remove stuff, be careful not to touch and make a short while testing to see if it works. Getting the bug out of the box means finding the bug, they hide in the the best hiding places.
  DMM Tests and debugging page reads/applications are recommended.

[black mariah]

Based on stats it's a 90% that somethings touching the box, which should touch ground.

Yep! I've had that problem a few times. Housing your stuff in plastic boxes eliminates THAT annoyance.

[Mr. D]

Well, we took the circuit out of the box and moved and twisted it, and still the buzzing doesn't go away. also, we taped up any exposed wiring that was exposed. i could try again i suppose.

alex

[Mr. D]

ok, so i decide to plug in the effect and try moving some wires around and so on. this is the first time i touched the pedal in 5 days. to my surprise it sounds and works fine, but as time went on the buzzing came back. is that possible? or did something shift in the box? i say this because like i said when we first tried it, it worked and then didn't. now i leave it alone for 5 days and it works, then it doesn't.

alex

[sfr]

I'd double check any offboard wiring - it's very easy to break a wire at the board or pot or jack or whatever when installing it, and not realize it, and get intermittent connection after that. 

[Mr. D]

ok, no luck. every connection looks good. it sounds like it's clipping (similar to a fuzz sound) but it is only on the initial attack of the note. could it be the transistor clipping? when we play notes very lightly there is no buzzing sound. we were wondering if the 820k substitution could make such a huge difference. still, that doesn't seem to explain it working right a couple times, then not. now it constantly buzzes. help!

sorry, we're noobs.
alex

[Mr. D]

We rewired the whole thing and put thicker wires in... no change. We bypassed the pot and switch for testing purposes. Still no change. Something on the board i guess. Can anyone help us? should we just start over? quit life?

alex

[jlullo]

alex,
i know it sounds awful to have to do, but your best bet would be to gut it, and rewire the whole guy back up.

jonathan