LPB Debug / Layout Verification

[mremic01]

I decided to try my hand at doing up a small perfboard layout based on GGG's schematic for the ElectroHarmonix LPB. I just put it all together, but unfortunately it doesn't work. I don't have a camera on me to take pictures of the perf, but here is my layout. I tried putting in the transistor the other way, and reflowing the solder joints. I'm hoping I just messed up somewhere in the translation from the schematic to the layout. Does this look correct?:



Here is GGG's schematic that I used: http://www.generalguitargadgets.com/pdf/ggg_cb1_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

[blooze_man]

The 100uf cap needs to be connected to 9v. You have it coming off the tranny's collector. Looks fine otherwise

[mremic01]

I didn't see that. Thank you.

[mremic01]

Ok, I moved that 100uf cap to 9v, and it works, but the signal at max seems to be about the same as my signal when bypassed. It might even be a little bit weaker. The pot does its job just fine, and when I connect the output jack to the board directly it still seems to be at about unity gain. It does break up nicely with some nice crunch if you dig in though.

[Renegadrian]

That cap is to filter hum from the power and it's not mandatory. you can try to lift it off and it should work fine, and you'll have no noise/hum when using a good wall wart. otherwise, the positive leg of that cap should be wired BEFORE the 10k res. Here you can find some layouts I made on vero!

[mremic01]

I got a chance to sit down tonight and figure it out. Turns out I had used the 1k that GGG has in their schematic for the LED where I should have used a 10k in the circuit. I fixed it up and it works now.