Stopping interference on the fuzz face

[msurdin]

hey all,

I am busy building 2 fuzz faces. Npn, the ggg layout. One i am using bc109c's and the other bc108c's
How can I keep this from being interfeared by radio stations and other things?

I have heard put a cap on the collector legs of the transistors...

Thanks

Matt

[slacker]

Build them first if you're lucky you won't get any interferance problems. If you do you try putting a small capacitor between the collector and base of Q2 something like 100 - 200pF should work. You can also put something like a 0.01uF capacitor from the input to ground, this might get rid of some treble but it should stop any radio interferance.
Out of interest why are you building 2, BC109Cs and BC108Cs are both very similar high gain transistors so they probably won't sound any different. If you used BC109Bs or old BC109s they have lower gain and then they might sound different.

[msurdin]

Should I know anything about the side effects of putting a cap there? Which part of q2 is the is the collector and the base?

Well my reason is I was talking to a fellow builder who uses newer bc10..."s. He told me bc109c's are higher gain the bc108c's. If this is not true would It be best to change the bc108c's to bc108b or just bc108's?

Thanks

Matt

[GuitarLord5000]

Best thing i've seen to date to stop RF interference  is from the runoffgroove Tantalus Project, here:
http://runoffgroove.com/tantalus.html
Put a 1k resistor on the input of the circuit.  I built this fuzz quite some time ago, and it worked well.  It didnt seem to affect the sound much either, if I remember correctly.

[msurdin]

So where the wire goes from the in jack to the board put the resistor there?

[GuitarLord5000]

That should do the trick, yes!

Let me know if it works out for ya.

[Dragonfly]

Best thing i've seen to date to stop RF interference  is from the runoffgroove Tantalus Project, here:
http://runoffgroove.com/tantalus.html
Put a 1k resistor on the input of the circuit.  I built this fuzz quite some time ago, and it worked well.  It didnt seem to affect the sound much either, if I remember correctly.

a small value resistor with a small (10-47pf) cap to ground directly after it usually solves any issues.

also, a large value (47uf-100uf) electrolytic cap to ground from the power supply will help filter and quiet power supply issues....