fuzz face radio interference

[gdmart]

how do I get rid of radio interference on my fuzz face 69 build.when it is turned up all the way,with volume at 7-8 I can get the dodger game on am radio.how do I fix this??

[Ge_Whiz]

Use silicon transistors instead of germanium... :twisted:

[Bernt]

Use silicon transistors instead of germanium.

...would probably not solve it. Experiment with - say a 1kohm resistor in series with the input, close to the first transistor, and a small cap -  100p  - from the base to ground.
Experiment, and good luck!
Bernt.

[petemoore]

I was able to tune a distant wierd sounding station in a FF. PDGood reciever...

[Lonestarjohnny]

Now ya know where they got the idea for a Transister radio, :lol:
Only joking of course but you just gotta use shielded wire for all off board run's and then some guitar p/u's can add to this problem, make sure your guitar is running a proper ground and I shield all of mine with Shielding paint that i ordered from Stew Mc Donalds, and its water based so you can clean up any bloches you might get with just a wet towel !
Johnny

[the_badcliff]

I built a silicon fuzz face that picks up christian talk radio.  I can't imagine getting rid of it, its fantastic.

[gdmart]

Ok ,so do I have to use shielded wire for the input and output wires?,if i put a 10pf resistor  from collector to base on the transistors would that help?

[bwanasonic]

BTW-

When auditioning a Fulltone 69 compared to my DIY Ge FF at a local music store, I found they BOTH picked up AM radio (store Epiphone Casino> Fuzz > store Fender Twin) . I rarely have a problem with this at gigs or at home, so I'm not sure what factors were at work there, other than geography, and that particular setup. I don't currently use any true single-coil pickups (just Bill Lawrence 280s and 290s and various Humbuckers) so the P90 in the Casino might have been part of the equation.

Kerry M

[john1056]

Assuming the schematics are kinda similar, take a look at the Runoffgroove sili-face.  I built one, and the 100pf cap between the Q1 collector, and the Q2 collector made a huge difference for me without changing the tone.  I had to use a 201pf cap though.

http://www.runoffgroove.com/sili-face.html

[gdmart]

So just to be clear I solder one 100pf cap from the collector leg of Q1 to the collector leg of q2 ??.dont I take a chance of putting to much heat to the transistors? Im using the guitar gadgets pcb pnp neg ground.Is this the only way to get rid of rf noise?? :?:

[bogart_sci]

I was able to tune a distant wierd sounding station in a FF. PDGood reciever...

Bernt ... this is gold! I used a 470 ohm resistor and a 1nF ceramic cap from Base to Collector. Worked a treat! This was on a BC108 Silicon FF. I am ging to use this on every build I do from now on

[K Zustang]

Thanks for sharing your experience.
Where did you stick the 470 Ohm resistor?

I am having RF noise on a 69 FF clone and also on my Orpheum clone and on other early style fuzz circuits.

[GGBB]

Where did you stick the 470 Ohm resistor?

in series with the input, close to the first transistor

Sometimes the resistor alone is enough to get rid of RF in a FF.

[digi2t]

Blast from the past....

http://www.diystompboxes.com/smfforum/index.php?topic=80070.0

[K Zustang]

Thanks so much.
Any idea how to tame noise in the Orpheum or Fuzzrite circuits?

[pinkjimiphoton]

yeah, those are real dependent on transistor gain and leakage.

try adding collector trimmers, that will let you tune them into a less noisy range.
also consider adding small caps... maybe 5-220pf between b and c on both transistors.

make sure you have a current limiting resistor and a cap shunting to ground on the power supply inlet.
that will help, too.

[midwayfair]

Thanks so much.
Any idea how to tame noise in the Orpheum or Fuzzrite circuits?

What kind of noise?

In my experience those actually have a pretty good signal to noise ratio. They're loud as balls, so they'll amplify line noise ... keep your input signal clean.

[pinkjimiphoton]

they got really big baalz at that, fer sure.. but i found some transistors to be a lot noisier than others when i built the umi buzztone thingy a ways back.
i thought he meant something like that.