Hallo
Cann anybody give me an advice? Last year a bought some equipement for
recordinding a small childrens choir.
I'm using a Behringer UBB1002 (5 mic. ch.) ****table mixer (with the
220V powersupply). Analogue recording takes place on a Sharp Mini-Disk
recorder or on a laptop.
When I'm connecting my Superlux CM-H8K condersor mic's to the mixer --
via DAP 6-10 meter XLR-cables-- I hear a low level 50 hz hum (with
several harmonic's) via my headphone. The headphone is connected
direct on the mixer.
It starts when I'm switching the Phantom power on, in order to
activate the amps in de mic's, and gaining the mic's up.
When I connect some older AT microphones (a-symm.) I do not have the
problem.
The first time a heard it, it was on location . I thougth that the
cause were some light-dimmers in the concert-hall.
Coming back home I stript the configuration (only mic's -> mixer ->
headphone). But the problem still exists. I do not know if the problem
was there before. Most of the time I could filter the low frequnecies.
This time this wasn't possible, because I had to record a cello too.
Who cann help?
Cann the cause be that the UBB10002 only supplies only 23 V. for the
Phantompower? Or is somehing wrong with de AC/DC conversion of the
mixer?
Regards,
Peter
