Avalon AD2022 ?....ground loop ?

Discussion in 'Preamps / Channel Strips' started by Swift, Feb 7, 2005.

  1. Swift

    Swift Guest

    I have the Avalon and when I use the DI's on the front with a Roland XV5050 I get a loud Humm. It also hapens with my AKAI MPC 4000 sampler.

    I've dismantled my studio, and plugged in only the Roland and the Avalon through my Roland 2480 HD recorder. No luck

    I've tried the Ebtech product

    I've taken the unit with the sound module to the shop I bought it at and there was no problem..no humm.

    The Avalon has all the latest mod's.

    I'm assuming now there is something in the wiring of my home/studio that is awry.

    How would I communicate this to an electrician. What would they look for??
    Any help appreciated.

  2. tedcrop

    tedcrop Guest

    A funny thing but unrelated probably I own a U5 which I love but sometimes when I unplug everything from it it picks up this really weird broadcast in an undetermined foreign language.
  3. Kurt Foster

    Kurt Foster Distinguished Member

    Jul 2, 2002
    77 Sunset Lane.
    ever notice when RF invades the audio it's usually a Mexican radio station ??? I wonder why that is ???

    This sounds like a ground loop ...

    Is all your gear running on the same electrical circuit?
  4. Swift

    Swift Guest

    well...if you mean wall socket. yes. I have 2 furhman power strips going into the same wall outlet -

    But I've already tried using different wall sockets in the room. And as I said, I took the sound module and Avalon to the shop and hooked it all up - and no problem.

    What's really weird is in my studio, the sound module does'nt even have to be turned on..and when I try to connect 1/4's in / out to the Avalon the loop occurs..without the module even being turned on.

    The shop talked about some $1500 Furhman iso box that "real" sudios use, so they are never "connected" to the city electric...so to speak.
  5. anonymous

    anonymous Guests

    Feb 10, 2001
    Swift ... if the hum is 60Hz then it may very well be a ground problem between the two units... for grins you might want to try a cable between the two units that has the shield lifted from the sleeve on one end. You may have a ground potential between the sampler/keyboard [whatever the hell it is] and the Avalon.

    Does this same phenomenon occur if you go through a DI into the mic input on the Avalon? Most DI's will have a "ground lift" switch that can be most useful for fixing hums and buzzes.

    If the hum you speak of is actually a "buzz" [higher frequency information... a hum is usually a 60 - 120 -180Hz affair... a "buzz" is something in the upper frequencies... minor point] then it could indeed be some kind of weird RF problem. Radio Frequency stuff is at best voodoo. It can come from the strangest places, change during the day... happen in one spot and not happen 6 inches to the left... it's some spooky $*^t.

    The fix for that will not be through an electrician but through a technician that is familiar with RF events. The local tech from the AM radio station might be someone to call... they usually will do after hour gigs for cash or will be able to recommend someone who will.

    Best of luck with it.
  6. Swift

    Swift Guest

    Thanks Fletcher -

    Yeah, I've tried all kinds of things including what you've described..but the loop is still there.

    What's really weird is I have a Novation keyboard that uses a wall wart, and going into the DI's on the Avalon with the Novation produces no humm/loop...crytal clear and quite.

    As I said, even turning the Roland sound module off, and plugging into the DI's of the Avalon prduces the humm. So the power of the culprit is off...and i still get a humm.

    Now, I know the Avalon was'nt designed as a DI unit for keys and guits...and it shines with microphones!!! But I love the sound I get when I track and can run a Keyboard Module through the Avalon...sound just gets deep and present..

    So it's weird- I've got some weird fkg problem in the wiring in my studio ...which is a space above my garage ..built 3 years ago.
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