Re: hum when biamping -- ground loop or interference?

On Jun 25, 1:44 am, Lee Roberts <lrobert...@xxxxxxxxxxxx> wrote:
Hello all,

I'm hoping that someone can give me some pointers on how to deal with
a really annoying hum problem with the biamped rig I'm trying to
cobble together...

The amps are a Hartke 3500 and an Ampeg B2R, rackmounted. Each amp is
driving one 8 ohm cab. I'm using a Boss DI-1 to split the signal from
my bass. I've tried other signal splitters but the result is the same
either way -- annoying hum from both amps.

Each amp is dead quiet when used by itself. There's a slight hum when
both amps are powered on, even with nothing connected to either input.
Connect to the input on either amp, and the hum gets a little louder.
With the inputs on both amps connected it's louder still, even with no
signal from my bass. It's not noticeable when I'm playing but very
annoying when I stop.

I've swapped out cables from here to Sunday and nothing has helped.
I've moved the speaker cables as far away from the power cords as I
can, but it hasn't made a difference. I also tried separating the
amps in the rack -- I had originally mounted them one on top of the
other so the chassis were touching. Didn't help.

I've tried everything I can think of, which isn't much. I'm sure I've
probably missed something obvious. Any advice would be much
appreciated. Thanks for your time.

Just going to throw this out there... Why don't you take the FX Output
from the Hartke, and run it into the Ampeg? From your responses, I
think it's your "pigtail adapter" that's causing the problem... but I
could be wrong.

Corey
.

Relevant Pages

  • Re: hum when biamping -- ground loop or interference?
    ... The amps are a Hartke 3500 and an Ampeg B2R, ... either way -- annoying hum from both amps. ... It's not noticeable when I'm playing but very ... I've moved the speaker cables as far away from the power cords as I ...
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  • hum when biamping -- ground loop or interference?
    ... The amps are a Hartke 3500 and an Ampeg B2R, ... either way -- annoying hum from both amps. ... Connect to the input on either amp, and the hum gets a little louder. ... I've moved the speaker cables as far away from the power cords as I ...
    (alt.guitar.bass)
  • Re: hum when biamping -- ground loop or interference?
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  • Re: hum when biamping -- ground loop or interference?
    ... The amps are a Hartke 3500 and an Ampeg B2R, ... either way -- annoying hum from both amps. ... If not, modify a jack lead (by removing the ground connection at one end - make sure you mark the lead, so you know which one it is), and use that between the DI and one of the amps. ...
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  • Re: hum when biamping -- ground loop or interference?
    ... a really annoying hum problem with the biamped rig I'm trying to ... The amps are a Hartke 3500 and an Ampeg B2R, ... either way -- annoying hum from both amps. ... Sounds like a ground loop, doesn't your DI have a ground lift switch?. ...
    (alt.guitar.bass)