Does the H9 have any switch to toggle between Line and Instrument or anything like that?
Sure - master bus send from WMD mixer goes to stereo Line out 1U module - then the jack line out module goes to H9. The H( return to the jack line in and then the line in 1U goes to the master bus return of the WMD mixer
Ok I think I see the potential confusion here. If the WMD mixer master send and return are line level, then you should not connect them to the Line In and Line Out 1U. The 1/8" jack on the Line In 1U is a eurorack level signal, so it’s got a pretty considerable boost over the line level signal. Similarly the Line Out 1U will attenuate the eurorack level signal from its input before sending it out.
What happens if you bypass the WMD mixer and just run from your source module to the Line Out, then back to the Line In from the H9 and then to your audio out? Actually, what is your audio out?
ok cool - I was thinking about that - my audio out is the WMD mixer - I was using the H9 as a master compressor before output - hence the send/return loop. Will try another approach…
ps. does it matter if I use try/balanced jacks on the I/O 1U?
The Line In and Line Out 1U both have balanced connections, but I don’t think this would cause the distortion you described. It’s probably worth checking with different cable types anyway though.