Also, how does one adjust the output level of the USB out? I’d been using another brand of mixer but the USB output level always seemed low. I’m hoping the Z10FX has some adjustment.
USB is digital.
You have to adjust the level in the analog before it gets to the usb or else adjust after it leaves usb.
You twist the knob on the amplifier, fed from the usb, to the right, or you increase the level in your DAW on the PC,
EG you could increase the fader level feeding the usb.
See page 14 in manual: https://www.allen-heath.com/media/AP7763_2+ZED10FX_UserGuide_A5.pdf
The ZED10FX provides 2 channels as a stereo pair only
but you can define the sources for these channels in some flexible way
and it depends on what you defined as the source where you can adjust the levels
but
maybe you see the ZEDi10FX
this has a 4in4out USB interface integrated
again with different source options, one of them includes all 4 microphone channels
.
