First Build

[jacobcarpet]

I'm a little new at this. I've been experimenting with a Mosfet Booster following this layout. I've followed it exactly as it appears. Every component value is the same.

http://4.bp.blogspot.com/_y7gcfRKQFgA/TEwVhhLfVpI/AAAAAAAAANA/Ocs0wgViO_w/s1600/ZVex+SHO+Updated+-+from+Zach+schematic-762360.png

I've built two of them so far. The first one built with a tagboard I built, the second on a vero board. I'm not getting any boost at all. I'm getting signal through with the volume turned all the way up. If I turn the volume down there is a "fffftttt..." sound and then silence. I thought it was a lack of 5K negative log pot, but I just got one in and that isn't the problem. I've gone over the layout a number of times and can't find any mistakes on my board. I've left it for a week and come back to it. I've checked all the connections again and again.

The voltages are 9.12 at D, 3.17 at G and 0 at S.

How can I better troubleshoot this circuit? Any suggestions would be greatly apperciated.

Jacob

[Barcode80]

you shouldn't be getting full supply at the drain. check your biasing resistor attached to the drain.

EDIT: also, the sound you are hearing when turning the knob is part of that particular circuit and is expected. it should crackle some when turning.

[jacobcarpet]

Thanks man, I'll start there.

[jacobcarpet]

Yup that worked. It sounds like turds, but it works. My 5.1k resistors are not 5.1k, they are more like .003R. Both of them in the package. Looks like this pedals gonna end up an A/B/Y pedal again. Thanks for your help.

Jacob

[Jaicen_solo]

Double check that you have the diode oriented correctly. It's there to protect against static damage to the MOSFET, so you can omit it for testing purposes if necessary.
Also, are you using BS170 transistors?

[petemoore]

My 5.1k resistors are not 5.1k, they are more like .003R.
 
  ?

[jacobcarpet]

My 5.1k resistors are not 5.1k, they are more like .003R.
 
  ?

Yeah, I bought a package of them from a local electronics store and both were bad. I put in a a 4.7K in its place and it worked fine. Its all good anyway. Its just an experiment. I had the parts and wanted to A/B this one with another pedal I have.

Jacob