Noisy Axe Ultra in FX loop

O

OverAmp

Member
I've seen the threads complaining of hiss using the 4CM, but I'm just using the Axe in my effects loop and getting a lot of noise.

I'm using a Carvin V3 head which has the most quiet effects loop I've ever used. I can load it up with a few pedals or a multi and it's amazingly quiet.

When I run my Axe Ultra in it I get a hum/hiss. Both the amp and the ultra are plugged into a Furman unit and I even have the Axe mounted with those little humfree tabs. No other pedals or rack gear I have causes this. It seems to originate from the AxeU's output.

I can turn down the input level and the output level to 0, totally pegged to the left and the hum is still there as soon as I plug the out into my effects return. At playing volumes this hum is objectionable enough that I could not play live at any volume with it. Otherwise my amp is very quiet.

This occurs even with no guitar plugged into my amp.

Any thoughts on this?
 
OverAmp said:
I've seen the threads complaining of hiss using the 4CM, but I'm just using the Axe in my effects loop and getting a lot of noise.

I'm using a Carvin V3 head which has the most quiet effects loop I've ever used. I can load it up with a few pedals or a multi and it's amazingly quiet.

When I run my Axe Ultra in it I get a hum/hiss. Both the amp and the ultra are plugged into a Furman unit and I even have the Axe mounted with those little humfree tabs. No other pedals or rack gear I have causes this. It seems to originate from the AxeU's output.

I can turn down the input level and the output level to 0, totally pegged to the left and the hum is still there as soon as I plug the out into my effects return. At playing volumes this hum is objectionable enough that I could not play live at any volume with it. Otherwise my amp is very quiet.

This occurs even with no guitar plugged into my amp.

Any thoughts on this?
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Sounds like you have a ground loop. A hum eliminator(isolation transformer) would probably make short work of it.
 
I thought that it would require an actual loop, right?

If I plug in nothing else at all- no effects send, no instrument, etc. and simply plug in one cord- the Axe U out to my amp's effect return the noise is there.

It is present on all presets, it is only marginally more noticable on the ultra gain type presets.
 
OverAmp said:
I thought that it would require an actual loop, right?

If I plug in nothing else at all- no effects send, no instrument, etc. and simply plug in one cord- the Axe U out to my amp's effect return the noise is there.

It is present on all presets, it is only marginally more noticable on the ultra gain type presets.
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Have you tried changing cables? Which outs on the Axe-fx are you using? Have you tried other outputs?
 
Still trying to figure this out. Tried both outputs and changing through multiple cables.

I would think my Furman would eliminate hum if that was it was well...
 
OverAmp said:
Still trying to figure this out. Tried both outputs and changing through multiple cables.

I would think my Furman would eliminate hum if that was it was well...
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Depending on the unit a furman can be not much more than a glorified power strip. I have had ground loops w/ a furman and humfrees. There is a reason they make isolation transformers.

this is a good methodology to follow:

http://www.ebtechaudio.com/findloop.pdf
 
As strange as it is, I had the same kind of deal with my mesa F-100 head ... Lots of hum when in 4cm mode ... The way I solved it - I tried a bunch of different cables for the cable that goes to the front amp input. For whatever reason one of them was significantly better in noise department and had almost no hum so I just used it from there on...

Mik.
 
OverAmp said:
This is the unit I have: http://www.furmansound.com/product.php? ... d=PL-PLUSC

Will do some more tests with some rewiring tomorrow.
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That power conditioner won't necessarily stop ground loops.

I have found that these work well for tackling the power side of the equation:
http://www.ebtechaudio.com/humxdes.html

Diagnosing and eliminating ground loops is not a fun process. If you go direct to a mixer/DAW is it quiet?

If it is, then almost assuredly it is a ground loop problem. If your 2 units are quiet alone but hum when hooked together that is a strong indicator of a ground loop and either a line isolation box or the link I gave above ought to clear it up.

I used to run a multiamp, multi-effect units rig. That thing was a nightmare to diagnose and eliminate the ground loops.
 
javajunkie said:
He'd need a special cable for that (XLR to 1/4). There are no 1/4 balanced outs on the Axe-fx.
Click to expand...

Yes. He has to buy one. No bundle on Axefx. :ugeek: :roll: :lol:
 
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