Zombii picking up radio?

[pryde]

Hello,

The title says it all. Not sure if this is normal or not but my Zombii picks up a specific radio station when it's on. I can hear it pretty clearly coming through the amp. The pedal sounds great and seams to work properly otherwise.

Is this an issue? Something specific I should check? Thanks for any advice!

[Om_Audio]

Something is amiss- you def should not pick up radio stations. I would guess a grounding issue of some sort but don't know enough to offer more info. My Zombii never picks up any radio that I can tell you with certainty.
C

[GermanCdn]

Check your power supply, I had a similar problem with a BSIAB when I was running it off an unregulated wall wart.  Running it off a battery or a regulated supply - no problems.

[TheCobbenator]

I blame the wiring in my house, but it happened to me one time during a storm. I just started playing along with the Mexican radio station. This was with my fuzz factory clone.

Also, our old bassist's SVT4 or whatever it was would pick up the same station after you turned off the power switch for about 1.5 seconds.

I mean, the purpose of the Fuzz factory is to be annoying. So by picking up radio it's only doing its job. (Ha?)

[Bluestrat]

It's not unusual for a fuzz pedal to have some RF interference. I built a Mangler and got a beautiful, clear reception of the college station near me. I solved that problem by putting a small 100pF cap on the input
jack. Attach it between the sleeve and tip. Worked great. I also did this with a Lovepedal "Les Luis" and it also worked great. Check out Analog Man's site for info on the range of caps you can use.

[pryde]

Thanks, I will try the cap on the input jack. the pedal does it with battery or 9v power also.

I have been reading up that this is a common issue with fuzz pedals. One suggestion was to unsolder the input wire nd use  ferrite bead? on it.

Not quite sure what this is. Does anyone know about this as a fix? How is it done?

Thanks

[Om_Audio]

A ferrite bead or collar is simply a magnet that is affixed to a conductor- they have snap on and other easy to install types:
http://en.wikipedia.org/wiki/Ferrite_bead

One suggestion was to unsolder the input wire nd use  ferrite bead? on it.

Not quite sure what this is. Does anyone know about this as a fix? How is it done?

Thanks

[bangerang101]

For RF put a 100ohm - 1k ohm resistor between the signal input wire from the pcb to the switch, or between the in jack and switch. Also, using a small capacitor (47-100pf) from signal input to ground helps.

For hum use a 47-220uf electrolitic capacitor from +9v to gnd. This filters the power coming in and helps clean up hum.

The best solution for RF on a fuzz face style circuit is to use a 47-100pf capacitor across q1 and q2's  collectors.

[Om_Audio]

some really good info in this thread- gonna have to bookmark it or something for future reference

[pryde]

I put a 100pf cap on the input jack (connected to sleeve and tip) and it certainly got rid of the radio pickup

BUT it really muffled the tone of my rig, even when the zombii was off. It lost alot of high end. Is this normal? I actually removed the cap because I did not like the way it altered the tone.

Maybe i will try the resistor method as mentioned above.

[DuctTapeRiot]

I had the same issue with my poindexter, but only was getting radio when it was on, so I put the filter cap on the foot switch so it was only going through the cap when the effect was engaged and I could make up for some of the lost highs end using the tone knob.  This helped a little but not enough for me.

I wound up using copper tape (same kind you use to shield pickup cavities) to shield the enclosure and tying it to ground with a little wire soldered to the tape and the ground of the DC jack.  This made a huge difference.  I still get a faint bit of interference when the gain is way up, but not enough that you can hear it if you are not standing right beside the amp.  When i was looking into this I read a bunch of stuff saying that the power in your house (or wherever you are playing) can be a factor, ie if your ground rods for your house are not making a good connection to ground will essentially cause the house wiring to become a big antenna.  I know for me a factor is I live < 1km from a radio transmission tower.

[Bluestrat]

I put a 100pf cap on the input jack (connected to sleeve and tip) and it certainly got rid of the radio pickup

BUT it really muffled the tone of my rig, even when the zombii was off. It lost alot of high end. Is this normal? I actually removed the cap because I did not like the way it altered the tone.

I've used on three pedals now and it hasn't been an issue for me. No loss of tone at all. However, that's my rig and home wiring so like the rest of this stuff your results might vary based on the specifics. There are a number of solutions posted. Hope one of them works for your situation. Keep us posted!