Help w/ Buzzing bass amp

Jason Arthur

unread,

Dec 8, 1997, 3:00:00 AM12/8/97

to

My bass amp, a Trace Elliot GP7SM 130 into a Carvin 18" cab, has been
making an annoying buzzing sound for sometime now. It buzzes whether
or not a bass is plugged in. When I turn up the volume of the amp, the
buzz gets louder, and when I turn it down, the buzz quiets down, too.
Does anyone know what might be causing this?

Thanks,
Jason

XXXma...@mailbag.com

unread,

Dec 9, 1997, 3:00:00 AM12/9/97

to

jar...@teleport.com (Jason Arthur) wrote:

More than likely the cable, bass, or something external creating
noise.

Mark

The truth as I perceive it to be.
Your perception may be different.

check the address

Matt Howe

unread,

Dec 9, 1997, 3:00:00 AM12/9/97

to

If you have separate gain and master volume controls, crank up the master
volume, and turn down the gain. If the buzz gets less loud, you at least
know its limited to your preamp section. I'm not sure about your model, but
most trace heads have a switchable eq, does the buzz continue regardless of
eq settings? There could be a million different things causing this, but
there's alot you can do to narrow it down. Check all the line-outs, preamp
outs, headphone jack, etc. If there is no buzz in any of these, try using
another speaker cable, or another cab. Also make sure your rig is grounded
properly. If there are any tubes in the unit, check them as well. Good
luck!

-matt

Jason Arthur wrote in message <348c788e....@news.teleport.com>...

>My bass amp, a Trace Elliot GP7SM 130 into a Carvin 18" cab, has been
>making an annoying buzzing sound for sometime now. It buzzes whether
>or not a bass is plugged in. When I turn up the volume of the amp, the
>buzz gets louder, and when I turn it down, the buzz quiets down, too.
>Does anyone know what might be causing this?
>

>Thanks,
>Jason
>

Wesley Fisher

unread,

Dec 9, 1997, 3:00:00 AM12/9/97

to

Lamp dimmers are notorious for RFI which can be picked up in the input
wiring or preamp section of amplifiers. Since the level of the buzz
varies with control setting, it's probably not caused by a power supply
filter. Try a shorted plug in the input jack; if buzz stops it is
unlikely to be an amplifier trouble.

If the amp has a tube-type preamp a heater-to-cathode short is possible,
but I'd look for an offending dimmer within a 50-foot radius.

Good luck,
Wes

Ralph & Diane Barone

unread,

Dec 11, 1997, 3:00:00 AM12/11/97

to

In article <348c788e....@news.teleport.com>,
jar...@teleport.com (Jason Arthur) wrote:

>My bass amp, a Trace Elliot GP7SM 130 into a Carvin 18" cab, has been
>making an annoying buzzing sound for sometime now. It buzzes whether
>or not a bass is plugged in. When I turn up the volume of the amp, the
>buzz gets louder, and when I turn it down, the buzz quiets down, too.
>Does anyone know what might be causing this?
>
>Thanks,
>Jason
>

Here's my best shot. Bad power supply caps. Each gain stage contributes
some hum, but each stage's hum is out of phase with the next one's. If you
tweak the gain just right, somehwere in the middle you can cancel most of
it. Check your power supply caps and their grounding.

Gumbass

unread,

Dec 15, 1997, 3:00:00 AM12/15/97

to

trace is imfamous for poor wave solder work on all there amps. take it to a
competant tech and have it checked out. it is more than likely something
stupid. it is probably not old enuf to be needing filter caps. T.C