Dr. Boogie working! Couple questions regarding hum and trimmers. (Picture!)

[elenore19]

I have the Dr. Boogie up and running. Sounds pretty good, just a couple questions.

First off, how should I go about adjusting the trimmers for the jfets? I have adjusted them by ear so far, and I have it sounding decent, but I'm wondering if there's a more precise way to get them in the "right" spot.

Then, I have some hum (some squeel) going on. When I'm playing it sounds great, but when I stop playing it starts to hum real bad with some intermittent higher pitched squeel type deals.
BUT! When I put my finger to the gain pot (now that I think of it, I didn't try the other pots...) the hum goes away and it sounds great! So how do I simulate my finger always touching that knob so I don't have to play guitar with one hand.....?
Will the problem get fixed when I finally have it placed in an enclosure? Or is there something else I can do?...


Thanks for the help guys (gals?). Here's a very rough photo of the pedal. I don't have the tools to drill the enclosure yet...(you can see it..it's the yellow one on the right.)



-Elliot

[richon]

whe you put the effect into the enclosure and use shielded cable for the input and Gain/pot cables it would (or should) be almoust dead silence.

[elenore19]

whe you put the effect into the enclosure and use shielded cable for the input and Gain/pot cables it would (or should) be almoust dead silence.

Shielded cable?
Enlighten me and my ignorance!

[richon]

it's like coaxial cable ...   the outside metal acts as a grounded shield for outside signals (like Radio frec or even the ones from the pedal itselfs avoiding oscilations)

[ghostsauce]

I just built one a few months ago and I didn't even need shielded cable.  I just slapped it into a metal box and it's been pure awesome, aside from obsessing over which fets sound best. I've never had any noise from mine, ever.  I can even run it with an OS-2 at the same time, which is a scary thought, but it's silent if I don't go nuts with the gain on the OS2.

[Angelo777]

Can someone who built it tell me which schematic you used or even send a picture ? I have built 2 and they both dont work !

[ghostsauce]

Looks like he built the same one as me, which is the pcb version from this site: http://gaussmarkov.net/wordpress/circuits/dr-boogey/

I got John Lyons to make etch the pcb for me, and he was really quick. Once I got that in the mail I soldered all the parts on and voila, a dr boogey.

[oldrocker]

Angelo777 I noticed you wrote that you built two and both don't work.  I might suggest to keep working with one so you can track down your errors.  Building another with possibly the same and or more problems is going to frustrate you more.  Pick one that you built and just work on that one until you solve it.  Many times when debugging a circuit I find a problem when I remembered during the build what I might have screwed up.  If I had built two It would have been harder to think back on the errors. 

[elenore19]

it's like coaxial cable ...   the outside metal acts as a grounded shield for outside signals (like Radio frec or even the ones from the pedal itselfs avoiding oscilations)

Could you maybe throw a link my way?
Could I pick this cable up at a local Ace Hardware or something?
Maybe radioshack?

I just built one a few months ago and I didn't even need shielded cable.  I just slapped it into a metal box and it's been pure awesome, aside from obsessing over which fets sound best. I've never had any noise from mine, ever.  I can even run it with an OS-2 at the same time, which is a scary thought, but it's silent if I don't go nuts with the gain on the OS2.

Yeah, I'm hoping that's what will happen. Sadly I won't have the tools to drill the enclosure for 2 weeks. So I won't find out if it works until then.

Can someone who built it tell me which schematic you used or even send a picture ? I have built 2 and they both dont work !

The gaussmarkov one. It's linked in someone else's reply.
Seriously try and fix those bad boys. The debugging process sucks, but it's worth it, it helps you learn and you get the pedal fixed!