Quote Originally Posted by alessa View Post
It's got XLR input, i connect the balanced output of my Soundcard RME fireface 800, it is wired in balanced stereo jack to XLR..
Please do check the resources given in post #27.

 Two different “base levels” are in use:

0 dBu: 0.775 V RMS, this would be 1 mW into a 600 Ohm load
0 dBV: 1.00 V RMS

Pro Equipment uses one of these levels:

+4 dBu: 1.23 V RMS. standard pro level
+6 dBu: 1.55 V RMS. non-standard pro-level

Your soundcard supplies a (too?) high level at Full Scale level in the digital section (dBFS):

Input/Output Level @ 0 dBFS @ Hi Gain: +19 dBu
Input/Output Level @ 0 dBFS @ +4 dBu: +13 dBu
Input/Output Level @ 0 dBFS @ -10 dBV: +2 dBV

The transformer gets into saturation @ 0 dBu:

Distortion: <1% at: 100mW @ 300Hz, 1mW @ 30Hz

It can not handle the pro levels, resp. it will generate heavy distortion,
and You can very easily overdrive it with Your soundcard.

The transformer is of low quality and will be overdriven by most "audiophile" CD players, also by most consumer CD players.

Ruediger