Ok got two problems with the performance of my UX1, possibly they're related.
The first problem I noticed a few years ago at the same time that I upgraded my Mac OS to Lion, though that might be a coincidence.
The problem is this: sometimes when I launch Pod Farm either with or without Logic (ie. as a stand alone, or as a Logic plug-in audio unit) the sound of the guitar distorts and collapses so that there's absolutely no sustain. When I first observed this happening I thought there was something wrong with it, but discovered that if I took out the USB cable out of the UX1 unit and then put it back in again (i.e. turning it on and off again) it would correct the problem and I'd hear the tones as normal.
This happens just about every time I use the UX1 and I'm almost prepared to live with the workaround to fix it.
But I've since been doing a lot of recording with Logic X and I've noticed that there are sometimes input level differences between sessions. In other words, I record some guitar on one track on one day, then the next day, with all the same PodFarm amp and pedal settings selected, same Mixer settings and same guitar settings (always have volume knob up to full) - the sound levels recorded are considerably different, usually lower. You can see it in the size of the sound wave, it's a lot smaller on the second session.
I've done lots of experimenting to see what could be causing it - changing amp settings, mixer settings, plus the input and output knobs in the PodFarm mixer - and can't replicate the problem manually.
I've also checked the input level in the sound control panel in the mac for the UX1, and it remains the same at 75%.
Could what I've described suggest the unit is faulty?
Thanks in advance for your help.