Pedal Power inducing noise. How can I shield it???

Discussion in 'Effects, Pedals, Strings & Things' started by droptopt, Jan 24, 2012.

  1. droptopt

    droptopt Silver Supporting Member

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    Noticed that my new PP2+ that is mounted under my pedal train board is inducing some noise in a couple of my pedals. If I lift them off the board the hum goes away. Chorus and overdrive pedals.

    What can I do?
     
    Last edited: Jan 24, 2012
  2. droptopt

    droptopt Silver Supporting Member

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    Anyone else have this problem?
     
  3. jnepo1

    jnepo1 Silver Supporting Member

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    Try moving them to a different location. What type of power cable are you connecting from the PP2+ to the chorus and overdrive pedals? Are you using a daisy chain or an individual power cable. Also, if you have a wah pedal on your board, where is it located relative to the PP2+.
     
  4. chervokas

    chervokas Member

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    Yeah, although the PP2+ uses a toroidal transformer that has a smaller EMF radiation field than other kinds of xformers, there's still radiation of course. I've only had this problem with wahs right on top of the power supply -- and wahs of course are very excellent antennas for this kind of stuff -- but not with any other sorts of pedals. The pedal cases should provide shielding, are you sure they're grounded? Other than that I think you just have to try to route the pedalboard with the pedals that are less likely to pick up the hum in the position above the power supply.
     
  5. Ben C.

    Ben C. Member

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    Good question...
    I too have only noticed the hum / buzz when a PP2+ was closer than 4" to my wah. But when I was experimenting with placement of the PP2+'s, I literally had all pedals on and powered by the PP2+ and was placing the PP2+ directly on top of my pedals to hear if there was any interaction. No pedals had any interaction (and I had the amp cranked), save for the wah.
     
  6. droptopt

    droptopt Silver Supporting Member

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    Thanks everyone!

    I'm using the supplied, single power cable to each effect. No need to daisy chain as my board isn't that big. No Wah pedal at all.

    I'll try moving them around a bit but space is VERY limited.

    Speaking of grounding??? Other than the power cable from the PP2+, Do the pedals need to be touching the metal of the Pedaltrain pedalboard to ground them or is there something else? I have noticed that when another pedal touched the metal on the pedaltrain it hummed real badly so I made sure it was isolated.
     
  7. jb4674

    jb4674 Member

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    What power source are you using to plug the PP2+ into?
     
  8. droptopt

    droptopt Silver Supporting Member

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    The wall outlet.

     
  9. jb4674

    jb4674 Member

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    There's your problem. Try getting a decent surge protector (like a tripp lite powerstrip) and it should take care of the problem.

    Remember, just because the PP2+ has isolated outputs and it has a toroidal transformer, etc., doesn't mean that it won't fry if a surge hits it.
     
  10. droptopt

    droptopt Silver Supporting Member

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    So the tripp lite is going to provide filtering to prevent the hum from being induced into the pedals?
     
  11. chervokas

    chervokas Member

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    No, that shouldn't have any impact on hum induced from the xformer's radiation field. But I also don't understand why there would be hum with the enclosures contacting the peadlboard. How is the power supply connected to the board?
     
  12. chervokas

    chervokas Member

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    Don't forget you don't need to physically place the pedals in the order that they're wired in the signal chain. Get some slightly longer interconnects so you can reorder the physical layout without changing the signal chain order. And check everything for continuity to ground. I'm not sure why touching the pedalboard itself should cause hum. I don't think the board should be a ground connection, unless two grounded pedal chassises are touching the board causing a second ground connection between them and maybe a ground loop.
     
  13. droptopt

    droptopt Silver Supporting Member

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    I think I can re-order a few things.

    The PP2+ is mounted to the pedaltrain using the pedaltrain's supplied brackets. The brackets screw into the PP2+ and to the pedaltrain itself.

    I guess I thought that with the popularity of the PP2+ that if this was a known problem that someone would have figured out a nice way to address it rather than a signal re-route. Especially since the PP2+ is often mounted under pedaltrain pedalboards and pedals are typically located on top of where the PP2+ is located.
     
  14. chervokas

    chervokas Member

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    Yeah; I have mine mounted the same way and as I said the only hum problem I had was with a wah.
     
  15. jb4674

    jb4674 Member

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    Not to sound argumentative chervokas but, how would placing the pedals in the order that they're wired in would degrade any noise/hum? I have 8 pedals on my board and they're not necessarily wired in according to the signal chain. Although I'm using 2 separate power supplies, I'm getting no noise whatsoever.
     
  16. chervokas

    chervokas Member

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    The hum the OP is getting is inducted hum from certain pedals when placed on top of the power supply, as per his initial post. It happens, even with the toroidal xformer in the PP2+.

    As he mentions in his original post when he lifts those pedals up, away from the power supply, he's not getting the hum. The solution is to re-order the pedals so that those pedals that are susceptible to that inducted hum are not directly above the power supply -- not necessarily to re-order the signal chain which I presume the OP doesn't want to do, but just the physical layout so that those pedals aren't directly above the power supply.

    I had the same problem with a wah above my pedalboard mounted PP2+, but moving the wah to the right side of the board so it was not directly over the power supply eliminated the hum.
     
  17. jb4674

    jb4674 Member

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    Oh, I see. I wonder why my wah isn't making any noise (not like I'm praying for noise, lol)? I have it above one of my power supplies (cioks) and I don't hear anything. I'm also using a midi switcher with a buffer in it, so that could have something to do with it.

    Thanks for clarifying it for me Chervokas :)
     
  18. chervokas

    chervokas Member

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    Count your lucky stars. Sounds like everything you have is well-shielded. I wonder about the shielding schemes in the two pedals the OP is having a problem with. Usually it's wahs -- which are like antennas for RF and EMF noise -- and sometimes vintage style fuzzes that are the problem, not ODs and chorus pedals, which I think the OP said where the ones giving him problems.
     
  19. sstweed

    sstweed Supporting Member

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    Does the OP have any pedals on his board NOT powered by the PPII?
     
  20. ubersam

    ubersam Member

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    @ OP - you might need something like this: http://www.lessemf.com/mag-shld.html#274 - Place it between the PP2 and the pedals. I've used that stuff successfully to shield the huge toroid xformer in a Furman voltage regulator in my old rack. I also used it to shield a couple of smaller EI type xformers that were also going into my rack.
     
    Last edited: Jan 31, 2012

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