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Pedals Picking Up Radio Signals

Voodoo Blues

Member
Messages
1,482
I have two Analogman pedals that both pick up radio signals when turned on, a Beano Boost and a Sunface. I use them both with batteries. Any idea how to eliminate this?
 

lefort_1

Nuzzled Firmly Betwixt
Platinum Supporting Member
Messages
15,787
:sarcasm




but really, RF and some pedals do not get along.

Before chiming in with ideas, I'll let the builder do so...he's usually around.
 

Voodoo Blues

Member
Messages
1,482
I actually did ask Mike some time ago but he said he couldn't help because he can't recreate the issue in his shop.
 

fahrner

Member
Messages
643
Are you near a radio station? If so it may be hard to find a solution.
Here's another test you can do to help isolate the problem;
Unplug your guitar cable from the pedal input (pedals under battery power and plugged into your amp). Do you still hear the station?
If no then the RF is probably coming in through the guitar cable/guitar and being amplified by your pedals.
Make certain you're using a good guitar cable.
There are more possible solutions once we isolate the problem.
 

Tim Plains

Member
Messages
6,140
I would love to know this, too, because I moved to a new house a year ago and have the problem since with some pedals / amps. I know it's not the gear because everything is fine when I play elsewhere. At first, it was only a TK Imperial I was having this problem with and it was unbearable. To the point I traded the amp. I don't think it's a grounding problem because it's not an issue with all my amps and only certain pedals through certain amps. I.e. Throbak Stone Bender through a 2061. The Stone Bender is fine through everything else. The 2061 is fine on its own and with everything else. I have also tried facing the amp in different directions. It will be fine one day and then not the next. Strange. One thing I have noticed is it is the worst on my second floor, better on the main floor, and no radio signal in the basement.
 

ecaace

Member
Messages
102
I had the same problem with a fulltone 70. I was using plantwave cables at the time radio inference came in. I switched to some 20 year old whirlwind cables I had and it went away. Not sure why but it worked try some other cables.
 

erksin

Senior Member
Messages
23,126
100% authentic vintage tones right there. Any more filtering and you kill all the good stuff.

Don't stop playing - crisis averted. lol
 

lefort_1

Nuzzled Firmly Betwixt
Platinum Supporting Member
Messages
15,787
Fahrner's test is a good starting point.

Try it first without the guitar, then without the cable.
If you have a second guitar, try that (ANY guitar...)
If your guitar has humbucking setting, try that vs single coils (this is just a way to get a 'tuning' on the circuit).

Try a couple cables. Swap them end-for-end and see if there is any difference.
 

lefort_1

Nuzzled Firmly Betwixt
Platinum Supporting Member
Messages
15,787
The problem you mention may well come from any pedals of the general fuzzface/trebleboost families where specific measures aren't taken...and those measures could negatively affect the toanz.... so first you have to be rigorous and eliminate the potential for problems with cables, etc
 

MmcGrouty

Member
Messages
3,852
My fuzz factory likes to do that sometimes. One night at band practice It was picking up an in depth discussion on WWII. It was awesome.
 

analogmike

Vendor
Messages
7,099
Fuzz pedals and Rangemasters are the worst, most opamp based dirt pedals don't have as much trouble.

Radio Frequency Interference (RF IF) is a tough one, most gain pedals like Fuzzes and even some wahs have a lot of RF problems.

Since we cannot duplicate the problem here (it has no noise here) it's not something we can definitely fix at our shop.

Gain is amplifying the RF from the air like a radio, it is tuned to the local station. Sometimes shortening wires or adding ferrite beads will help but since we don't have the problem here we would only be guessing. If you have a good tech he can try shortening the internal wires one by one and test to see if that helps, or he can try adding more and more ferrite beads and see if that stops the noise.

Also you can try to add a small capacitor on the input of the board or the input jack to ground, that often kills the noise. Try something small like 100pF then go bigger up to .01uF if needed. We often put a small cap right on the switch from the TO BOARD wire connection (gets connected to input jack when ON) to the GROUND connection.

Adding a capacitor on the Beano Boost will often help. We use a 221 (220pF) disk cap, from the output of the transistor to ground. The output leg is the one that goes to one of the volume pot lugs. It's usually a white wire. Tack a cap from there to ground (the body of the volume pot is a good ground).

.
Also dirty jacks can cause RF interference, try cleaning them with a swab and some contact cleaner.

A customer wrote :
"One thing I did was to uncoil all the power leads in the back of the rack. I had them coiled up pretty tight and then cable tied. This immediately helped, but I wasn't completely satisfied.

At this point, I noticed that to make the radio signal be it's worst, touching the audio plugs on the back of the power amp (Metal sleeves) would do it. So next I soldered some 4.7pf capacitors across the DC connectors on my pedals. "

another customer with RF problems with a sunface wrote:

"Thanks for the note, Mike. After applying an, ahem, no-to-low-tech technique it seems that the RF IF problem is gone. Get this: after reading your reply I got to fiddling with the guitar cables in the chain, which includes a Framptone Amp Switcher in front of two amps. Anyway, I just swung the guitar-out cable from the Strat around from the front and behind my body and presto/change-o, the RF IF disappeared. No contact cleaner, no screwdriver, no solder. No BS."

Here is another who found a simple fix for RF noise on a sunface:

"Thanks for your detailed response to my question. I was able to solve
the problem. I got a ferrite clamp from Radio Shack and tried clipping it onto my guitar cable. It eliminated some of the RF noise, but not all of it. I also noticed some loss of clarity from my guitar signal so I decided to ditch the ferrite and try adjusting the internal trim pot. I set my guitar volume to the most offending spot and adjusted the trimmer until the noise went away. I only ended up turning it down a bit. I would guess it's somewhere around 85%. Now I can use my guitar's volume knob to get that sweet spot w/o the RF interference."

The "CLEAN trimpot on the Sunface is an excellent way to reduce noise, just try adjusting it a hair.

Another customer fixed his wah by removing the in and out jacks and sanding down the inside of the pedal to bare metal for better grounding contact. Then he tightened down the jacks well and the RF noise was gone. I fixed a HUMMING wah by making sure the bottom plate was FLAT and tight. The wah plate may help with that.

One customer with a noisy King of Tone fixed it by installing a Burr Brown OPA2134PA op amp chip. Not sure why that worked but you can try it to replace any standard dual op-amp as in a tube screamer, etc.

Hope that helps, good luck!
 

fahrner

Member
Messages
643
I'll give it a try but if this was the case wouldn't it happen with all drives? It's isolated to the Analogman pedals.
Mike just added some good stuff.
My preference is to make certain that the issue can't be resolved externally first. Much preferred rather than modifying the pedal(s) at the risk of changing their character.
As others have said, some pedals are just more susceptible to RFI than others. Doesn't make them bad. My experience is that the issue can usually be resolved externally.
 

lefort_1

Nuzzled Firmly Betwixt
Platinum Supporting Member
Messages
15,787
Mike is The Man. He knows his product. Listen to him.



I'm going to dig back about 30 years in my experience to when I did some radiated and conducted emissions design and testing.

There are a couple more things to try:

1) similar to Mike's customer who sanded the jack inputs to make better metal-to-metal contact, try these:

-a) Take off the back panel of the box. If there is paint on either the box OR the backpanel that prevents metal-to-metal contact, remove it. Most paints are not conductive (espec at RF frequencies) and its existence can allow the backpanel to "float" electrically as far as RF is concerned. At 6-800 Mhz (classic CMOS slew-rate), you'd like to have a MAXIMUM 3 inch 'gap' between hard-contact stitchpoints (ie screws or other solid tiedowns) which is just about the space between the crews on that box. If you can get some HARD contact, metal-to-metal (a few atoms-gap is enuf for RF to POUR in!!) inbetween those screws, then you are ahead of the game. Forget looking for a gap; no one's eyes can see the spaces RF can sneak in to.

-2) Those screws - the ones at the corners of the box. Take a look at them.
If there is ANY sign of residue (I.E. Loctite, glue, goop, grease, etc) clean them as best you can with water/scrubbing, then isopropyl alcohol and let the dry completely. If you can force a little isopropyl-OH into the screw-holes, then blow them out with compressed air (that **** you spray on your keyboard to keep it clean).

-3) I had one project that I SWORE was gonna be dead silent, but it sang like a jaybird when a local 2 meter Hamm keyed his mic. I crammed a little aluminum foil between the enclosure halves and it dropped the radiated noise interference by 30 dB or more. Sometimes, all it takes is a little extra bit of conduction in between those screws...



Hell, lets not even get to the next level (conducted noise....Mike's already given you one possible corrective action)...after you've tried Mike's suggestions, then thought about my 2 cents, check back in.
 

Pedal Dan

The Island of Misfit Pedals
Messages
11,773
I use my '97 Zvex Octane to tune in the evening broadcast of Radio Havana.
 

cubistguitar

Member
Messages
6,056
A fuzzface will tune radio and its seems the better the dang FF, the more easily it will do it. both my Londons tune in 2 stations at once. My PTD Tornita has a preference for foreign music radio and late night preachers. I don't know if I would trust a fuzzface that didn't pick up a little bit of radio.

Of course this generally only true if my gtr volume is at 1-0. Once the gtr is audible, radio is gone. If it overlaps the real notes, then go through the more involved task of grounding everything real good, add iron to the cables,etc.
 






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