OK, I've got the little bugger working, more or less, I would say rather less than more.
I can make it work only at 48kHz, no 192, which is a deal-breaker for me, since I want to be able to measure at least up to 60kHz.
I would have expected some indication from the software that the interface was not responding...
The software...I guess these guys have never seen an AP screen in their life.
When I do a frequency response in loop-back mode, I expect the graph to be more or less positioned at 0 dB. No, you get an FFT screen, with the level between -40 and -80 (depending on the FFT size), which is mathematically correct, but just not what an audio guy wants. In FR mode, the scale should be offset according to FFT size. The procedure is in the manual, but it is unduly complicated; it should be done automatically.
Of course, there is nothing like a standard sweep available, frequency response test is done in FFT, with a modified Dirac as stimulus, which is not what you want for testing a power amp.
BTW, I haven't seen a hint of phase measurement.
The marketing blurb says that it is easy to program the unit to make sweeps and repetitive tests, but when you read the posts on the forum, you learn that the programming language is not available yet.
Marketing also says that third-party applications may be run on the hardware, but again, the forum says it ain't so.
They say they don't have enough resources and want to concentrate on the very important features, like allowing SPL measurement via a calibrated mic. First, I think this is not such a time consuming task, second, I consider this functionality as secondary to providing the possibility to create sweeps.
I'm disappointed and I feel cheated, so my QA400 is available for sale at cost ($213). Anyone interested PM me.
[rant] They didn't even deign to answer my questions. It's their company, their products, they do what they want, but I'm not gonna blow their horn. [/rant]
Now I have to find a nice USB souncard on which I'll run RMAA, AUDME or SigView.
