First of all, is there a user manual for the PH 9.0X? The 9.0 manual doesn't get into this.
I have a 9.0X on loan and I'm testing it with both RCA and XLR outputs (separately of course). I am using only the MC input.
There is a switch on the back, between the XLR sockets, that is not labeled but it appears to affect the grounding of the RCA/XLR outputs.
1) The XLR outputs work regardless of the switch setting.
2) I read that this switch should be set to RCA when using RCA outputs, which I am assuming is the DOWN position (?).
3) When the switch is in the UP position, the XLR output level changes slightly (+1 dB) but the MUTE selection no longer works. Also the MONO switch does not work (there is only a slight change in the sound but it remains a STEREO sound).
4) When the switch is in the DOWN position, all functions work as expected.
