Yesterday I turned on the 388, for the first time after several months of being without headphones, plugged a drum machine in to one of the line inputs and my new headphones in to one of the front panel headphone jacks, set the channel, right buss (I wanted to record a click to track 8) and stereo faders to unity, pressed the 7/8 buss select button, turned the pan control on the channel all the way right, armed track 8, started up the drum machine, and...

When I turned the volume control, no sound. When I panned left or right there was sound, at normal levels, but it was mono only. Engaging the mono button made the sound disappear all together. Like it was cancelling out.

I did try listening over the monitor outs via a separate amplifier, in case it's an issue with the internal headphone amp, but I think the cable I used is dodgy since there was no sound. I'm going to try with a different cable later. I'll update then.