Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups

Noisy Deville

Discussion in 'Glowing Bottle Tube Amp Forum' started by Berek Halfhand, Jun 24, 2013.

  1. Berek Halfhand

    Berek Halfhand Tele-Meister

    Jun 8, 2010
    We have a Deville backstage at church for the lead player to play through. It stays backstage and we run a 20' cord to it from his pedal board. We feed the PA with SM57 in front of it. Lately it has been exhibiting occasional spouts of noise. It sounds like the digital noise you would hear in any kind of audio amplifier if you get it too close to a computer. The sound is not loud, and is drowned out when playing, but in quiet times with nothing else going on, it is clearly audible in our in-ear monitors.

    There are of course no computers or any other digital equipment near it. It is now plugged into a specially purchased "clean" power strip that is supposed to filter out any line noise.

    It does not happen all the time, and we have been unable to correlate it with any other equipment. When it does happen, the panel controls do nothing to change it.

    My theory is that a tube in the power amp section is picking up signals from the wireless mics (of which there are several in use). Anyone have any other ideas?

    It was re-tubed within the last year.

    Thanks in advance.

  2. Abu Twangy

    Abu Twangy Friend of Leo's

    Mar 16, 2012
    Rocky Mount, NC
    Sometimes the guitar and the cord can act like a radio antenna.

    Years ago my bass rig picked up the 1975 World Series. During the break a customer slipped me a $20 to "tune" it in better so he could hear it on our breaks. I moved the cord a bit until the game became clearly audible and cranked up my amp a bit more to satisfy our customer.

  3. musicmatty

    musicmatty Former Member

    Aug 18, 2008
    That is a fantastic story thanks for sharing it!

  4. Fatknuckle

    Fatknuckle Tele-Holic

    Jun 28, 2012
    Gainesville FL
    Last week I was finishing up a rebuild of a 36-watt EL84 amp. I fired it up and got ESPN Radio and the NBA playoffs. Then I discovered the primary preamp ground was not connected. Hadn't experienced that before.

    All tubes replaced, including preamp? Any other cables, equipment, or network outlets near? Try moving the amp out elsewhere on the platform and see if it does it?

  5. stevenhay

    stevenhay Tele-Meister

    Oct 9, 2010
    New Castle Indiana
    How old is your church, and how long does it do it? Believe it or not, I've had the worst luck in churches with amps because of old worn out bathroom vent fans. Check it out. Sounds crazy, but is half the cause of older churches power line noises.

  6. waparker4

    waparker4 Doctor of Teleocity Ad Free Member

    Nov 9, 2011
    Philadelphia, PA
    Just an idea, related to another thread -- is there a footswitch plugged in?

  7. Berek Halfhand

    Berek Halfhand Tele-Meister

    Jun 8, 2010
    Church is very new, one of those all steel constructions that acts like a Faraday cage for cell phones. You would think that would help. I am considering getting a big cardboard box, covering it in aluminum foil and putting it over the amp.

    Footswitch is NOT in, did check that.

    Thing is so stinkin' intermittent, so annoying!

    This week the sound tech experimented with running wireless from guitar to pedal board, and another wireless pedal board to amp. No difference.

    Thanks for your thoughts.

  8. Tele-phone man

    Tele-phone man Tele-Afflicted

    Sep 11, 2006
    Asheville, NC
    Substitute another amp for now. Plug it into the same circuit as the DeVille. Keep the DeVille powered up and mic'd to see if the anomaly occurs with nothing connected to the input of the amp. Any tube or other possible internal cause of the issue will recur, thus eliminating the board or input cable as the source of the problem.

    If the problem disappears, or moves to the replacement amp, you have isolated the trouble to something before the DeVille. If the trouble continues in the DeVille, and occurs in the new amp, you have an AC power issue.

  9. steveneddy

    steveneddy Tele-Meister

    Jan 16, 2012
    Unplug the input on the amp from the pedal board and see if the issue persists.

    My guess is it is one of the pedals, pedal board wiring or the cable from the pedal board to the amp - and/or the cable from the guitar to the board.

    Also try one of those ground lift plugs on the amp to see if that's an issue - ground hum from outside of the amp.

    Could be bad tube or tubes, bad ground, loose or damaged input jack - or one of the effects loop jacks.

    If all else fails to deliver the desired results take the amp to a qualified technician that is known in the area for tube amp repair.

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