Hi.

I didn't discover this problem, but I thought I'd bass it on. On a fairly large number of MOTU 24i interfaces, the analog inputs are reverse polarity! Can you believe that they could let something like that slip through? It makes ya wonder if they do ANY testing of their products. Anyway, there is a ROM upgrade from MOTU available to fix the problem. MOTU has told some people about it, but they haven't really made a big effort to get the word out.

If you want to test it, just play some wave file out of the 24i out, and patch it back into one of the inputs and record it. Compare the two (input and output) waveforms. It'll be pretty obvious if you have the reversed inputs. Just make sure you use a file that has an obvious polarity. In other words, don't use a sine/square wave or something like that. The effect of latency could give you a false reading.

If you discover you have the problem AND you are the registered owner, then MOTU will send you a chip. If you have never registered but still have your receipt, they'll make you register first. If you bought it third party, or lost your receipt or for whatever other reason, can't register, you're going to need to get used to hitting your reverse polarity button. They won't send the chip without proof that you didn't steal it.

-Gary