Alembic Stratoblaster BUZZZZZZ

[Mike92]

Hey guys! I just built a stratoblaster boost into a 1590a enclosure. I got it working, except whenever it's on it's got a really nasty buzz regardless of the level of the boost. I used this layout: http://www.tdpri.com/forum/attachments/burnt-fingers-diy-effects/186539d1371967348t-stratoblaster-help-please-image-3149420392-jpg
After I got the buzz, I rebuilt the board thinking that might be easier than figuring where I went wrong the first time, but it's still noisy! I'll try to post pictures tomorrow, but in the meantime, anyone have any ideas? A bad jfet? Something like that? Thanks!

[Mike92]

I should probably mention that I'm powering this with a T-Rex Fuel Tank Chameleon with it's own output so it probably shouldn't be coming from the power supply.

[nocentelli]

You could try a large value (47 or 100uF) electro cap across the rails on the board, I.e. positive leg in c6 and negative in d6 - that is if you have a cap physically small enough to fit that gap.

[Mike92]

Nope, I tried a 100uf cap there and it didn't seem to have any effect.
Here's a couple pictures if that helps. I know it's pretty sloppy (it was nice and neat until I started replacing parts to solve this darn buzz! -_- ) but I checked for solder bridges and it seems to be all good.

[mth5044]

Does it make the buzz when the board is out of the enclosure? Could be touching something it shouldn't when stuffed in that tiny box.

[Mike92]

Yeah it still buzzes out of the box. That was my first thought too.

[anotherjim]

Check you have the sockets wired right. Use DMM on continuity to check that in and out jack sleeves connect to enclosure and power ground. Then check tip contacts go to the right strips on the board when effect is engaged.

[Buzz]

I've made this circuit in a box and also in a guitar cavity.

I found 2N5457 and 2N5484 worked great in these, the J201 not so much. If you change transistor type beware the pinout. It would seem other people use a J201 to their liking so YMMV.

This circuit made a hell of a lot of bad noise unless it was in a grounded enclosure. So I'd be checking the grounding of your enclosure to your board, as Jim has already suggested.

Try hard wiring the effect too. Bypassing the stomp switch. Just something easy to rule out of the equation. Could be a faulty or cooked switch.

Also if this is in a stompbox take note that your layout doesn't include a pulldown resistor. It might pop when you engage the effect. I used 1M5 resistor between input and ground and that worked a treat.

 

[Mike92]

I tried wiring directly to the input and output and checked the ground with my multimeter and still nothing. I'm thinking that the jfet might be the issue since it was the only component that I didn't know how to check with my multimeter before putting it in. I might just re-purchase the components and try again. Maybe I'll try a 2N5457 or 2N5484 this time. What kind of change would I be expecting using one of these as opposed to the j201? I like the way it sounds with the j201 (besides the buzz obviously) but I'm always up for trying something new.

[Quackzed]

that pick of the solder side looks scary to me... and the parts side even looks a little greasy... i'd try scrubbing both sides with an old toothbrush and a little dish soap.
scrape away any loose solder bits as well as flux.
could easily be a bit of goop making an unwanted connection between parts/traces...
i've had noise as a result of crap between traces after modding/soldering and it disapearing after a good cleanup...

[Buzz]

If you like j201 stick with that type.

I don't think that's what is causing your buzz.

[caspercody]

Is that a solder bridge between the second and third row up, and three holes to the right on the left side of the board?