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Boneyard problems

Started by shawnee, July 17, 2011, 08:45:48 PM

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shawnee

Hello Everyone,
I decided to build a boneyard as my first pedal and so far, it's driving me crazy! I can hear humming and get volume and tone changes when turning all of the knobs but it doesn't pass guitar signal. I do get the bypassed signal when I hit the stomp switch though.

I didn't hookup the indicator LED's but I did jumper from B3 on the on/off switch to G2 on the PCB. I didn't hookup the crunch/hi-gain switch but I jumpered the pink and green wires and can turn the crunch pot and get more hum/volume. I didn't hook up the boost switch.

I have checked everything three or four times over the course of several days and still can't figure out the problem. Other than using a 2.2k for R4 instead of a 2k and a 100p instead of the 150p for C9, I used the same components. My voltages are pretty much the same as what Brian shows on page 2 of this thread with the exception of pin 1 on the LF347. I am only getting -0.7v instead of -2v

http://www.madbeanpedals.com/forum/index.php?topic=1708.0

I am running out of ideas. Any help would be greatly appreciated.

oldhousescott

Based on the schematic, pin 1 should be pretty close to 0v, so I think you are fine there. Jumpering the pink and green should also be OK. Your substituted values are fine as well.

Post some hi-res pics and maybe one of the eagle-eyes here can catch the problem.

shawnee

Thank you for the reply.
I think I ma going to make the test probe and see if that will help. I ma thinking it is a bad Chip at this point.

gtr2

It's more likely to be a wiring or solder bridge problem than a bad chip.  If you post some good pictures it could really help.

Josh
1776 EFFECTS STORE     
Contract PCB designer

mjcyates

Every problem I have ever had wound up being either a wiring problem or a ground bridge, so I agree with Josh.

shawnee

Thanks for the replies. I have been working late and haven't had a chance to troubleshoot until today. I checked everything again and still can't figure it out. I checked all of the pins on both chips to ground and only the pins that show ground on the schematic are grounded. I will try to take some pics.

shawnee

It's working! I'm going to let you guys in on a little secret. It matters which jack you plug your guitar into!  :-[  Yep, I am really that stupid. Anyway, this thing is LOUD. I think it sounds really really good but is there a way to get the volume down to a closer match to the bypassed clean signal?