fantom x 8 audio buzz help

[art burke]

Hi to all:

I was plugging my fantom x 8 into a mackie board the other day,
and using two different quarter inch cables, and trying different inputs to the board, I had a buzz (which sounded like a bad cable).
After using an adapter plug which removed the ground going to the AC cable, the buzz disapeared.

Could it have been the phantom power on the board causing this?

Thanks,

Art
PS...Any solutions?

[plasmis]

Sounds to me like it was a ground loop. You can eliminate these by for example connecting your audio equipment to the same extention cables on the same AC outlet, in essence connecting all your equipment to one ground point.

Phantom power on your mixer should have nothing to do with this, and you really should NOT enable phantom power on connections to synthesizers, fx modules, etc. On many mixers phantom power is supplied only to the XLR-connections, but I recommend you make sure before trying it. You could damage your equipment.

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There is no such thing as a stupid question.

[art burke]

I'll double check that today. I tried the Fantom into headphones and it sounds good.
I can't find what type of outputs the 1/4 jacks are.
I'm assuming unbalanced...But, are they line level or microphone level?

Maybe that was where the hum was coming from.

[MarkShovel]

Try a TRS (tip ring sleve) 1/4" stereo cable between the Fantom and the Mackie. The Fantom has a balanced output and most Mackie mixers have balanced 1/4" inputs.

Mark

[plasmis]

Good point, although it won't help you if you have a ground loop.

On stage or in other long cables you want to use balanced cables, but they only help you with the problems you get on that cable run...for example powerful magnetic fields (especially modulated ones like AC transformers), and the like.

A ground loop is still a ground loop. Only have one ground point, and it will solve it.

I had to correct myself: or have DI boxes with opto/separated grounds.
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There is no such thing as a stupid question.

[art burke]

Thanks to all:

The balanced cable fixed it!

Art