Behringer UCA200...

[foolintherain]

Awhile back, I bought a Behringer Xenyx 2222FX mixer, which has worked beautifully. It came with an RCA-USB interface (UCA200) to hook up the CD/Tape output on the table to the USB port on my iMac. When I first hooked it up, there was a very, VERY noticeable oscillating whine/hum noise coming through the speakers. I tried switching RCA cables and USB ports, but the whine persisted. I gave up on the UCA200 and just used my Lexicon Alpha interface, which has worked great for me with no hum.

But now I'm trying to reduce the clutter by getting rid of the Lexicon, so I'd like to see if I can get the UCA200 working. Is it just a crap device? Is there anything I can do?

 

[witzendoz]

The UCA devices work fine, what you have is a mains earth loop between the imac and the mixer which is looping via the usb cable.

Unfortunately the fix can be tricky, if it where a lap top (where most problems occur) I suggest using a double insulated power supply with no mains earth pin. You can buy an audio hum isolator but then you have yet another piece of gear. http://www.behringer.com/EN/Products/HD400.aspx

Try running an earth wire from the chassis of the mixer to the chassis of the computer, if you give the loop an easier path then the usb cable the hum may go away.

Is there any other gear plugged in that may be causing the earth loop? Just check.

I wish that someone would make an earth lifted USB cable for audio problems.


Cheers

Alan.