Originally posted by mortenfresh
And regarding the urei, I actually have a slight problem with it. For some reason if I crank up the volume(not overdriving the mixer) or my console gets a little bump the mixer kind of freaks out on me. Sort of goes into a weird oscillation. If I turn down the faders for the source playing it will disappear again. If you or anyone has a suggestion for a reason to this and perhaps knows what to look for in order to rescue the mixer please let me know.
This could either be an internal grounding problem or ageing power supply capacitors. If memory serves there were some internal grounding issues on early units...someone like Mario could no doubt go into more detail on that.
The capacitors are relatively straightforward for any qualified tech to replace, and I did this recently myself (using better-grade, higher-value parts both for audio coupling and the power supply). The improvement in sound quality (particularly the bass response) was not trivial.