Help out a fellow TB'er with his first pedal build

[LzeroKI]

So after spending alot of time reading on diystompbox forum, and Beavis Audio, I decided to try my hand at building a pedal. I decided to build the Bazz Fuss fuzz pedal because it seemed like a very simple circuit and all the parts could be bought at Radio Shack. I used the following schematic that I found on diystombox forum to build the pedal.



I couldn't find the recommended MSPA13 transistor at Radio Shack, but I could find a 2N3904 tansistor (as recommended by http://www.home-wrecker.com/bazz.html ).

So Ive got everything put into my breadboard and soldered up the volume pot and in and out jacks; hooked it up to my bass, turned the amp on and all I get is a loud buzz; I am fairly certain I have the volume knob wired right, as I can turn it down and the signal will fade from loud buzz to silence, so Im thinking the error is somewhere in the actual circuit. Since I am such a newbie I dont really know what to do as far as trouble shooting. Ive tried flipping around the transistor (incase I had it in backwards) it didnt seem to do anything.

Here's a quick mockup of the breadboard layout Im using, comparing it to the layout above I can't figure out what the problem is.



Any help you guys can give me would be very much appreciated.

Thanks guys!

[pharaohamps]

A buzz is typically due to a bad connection or grounding issue. If the buzz gets quieter as you turn down the pot, then you know the output and pot are OK but no guarantee anything else is good. From your breadboard diagram, it looks like you've got the circuit wired correctly, but I can't see your actual breadboard so again we're just guessing here.

Do you have a multimeter? You could use the resistance setting to check your connections (with the battery disconnected.) You could also measure the voltages on each pin on the transistor and that would let you know if something was wrong.

One more thing to keep in mind, the Bazz Fuss isn't a traditional transistor amplifier. There's no real bias for the base of the transistor, so if it conducts at all it will just go into cutoff, and it will be pretty nasty sounding. That's fine, since that's what you want, but it's not your "normal" deal.

[LzeroKI]

Well Ive actually got that problem solved now, I just needed to up the Resistor coming off of the base of the transistor to 100k.

Im now trying to add a couple more parameters to this circuit. I wired up a voltage sag as illustrated on the Beavis Audio website, but it didn't seem to do anything.

I tried wiring in a "Stupidly Wonderful Tone Control" from http://www.muzique.com/lab/swtc.htm and it didnt work either.

I was thinking about trying a BMP tone stack, but with everything else Ive tried on this pedal not working, I may just not even bother.