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Old 26th March 2008, 01:23 AM   #14
Kiwiburger
Lives for gear
 
Join Date: Feb 2006
Posts: 3,816
I'm trying to get my pair of API A2D's useable. I don't like the background hum/buzz. Using either an SM57 connected to the input, or a standalone battery amp with a single coil pup, I detect a lot of EMI coming from the API power transformer.

The top cover on the A2D's is aluminium. Is the 3124 the same? It seems to me that this is basically a large unshield torroid generating a huge EMI field. Would replacing the covers with steel help?

I get an audible buzz with nothing connected - just monitoring the digital output with a Benchmark DAC-1. I'm trying to hear the noisefloor of the converter, with the preamp on minimum gain. It gets worse with a mic connected - and the unit itself seems to be a main source of EMI in the room.
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