I’ve been using a TouchMix 16 for a few years now. I really like it. However, it’s starting to give me trouble.
I've been using a TM and also noticed as issue fairly early on with some of the input channels producing noise. It shows up quite clearly on the RTA and is well into the range that precludes use of those channels with any source that requires phantom power.
If you have nothing connected, noise appears immediately and remains rather constant as soon as you activate phantom power. Within a few a few minutes it will subside but reappears as soon as any signal arrives at the input.
The problem does not occur with dynamic mics, only when phantom power is active and only on the defective inputs.
I did a search online and found quite a few instances of other users experiencing similar issues. The response from QSC was disheartening. The construction of these boards is not amenable to service and the solution to resolve the issue is an entirely new motherboard - not covered by warranty. Too expensive so, IMHO not worth the risk of buying another of these.
A novice user could easily mistake this noise for distortion, overload, or a crappy microphone because you need to examine the channels RTA sans signal to see what's really happening on those inputs as compared with other good signal paths.
I'm resigned myself to check on these units each time I find them in a church or school etc. to see how common the problem might be and whether it's a defect that comes with age/use or is getting past QC right off the line.
