No signal from M-Audio Fast Track

[wchang]

I am on a trial version of SignalScope.  I am using a MacBook and an M-Audio Fast Track preamp.  Other applications (such as Audacity) are able to read from the preamp.  SignalScope detects the Fast Track, and even indicates that sampling is taking place (by reporting "actual sampling rate") but I get no waveform.  Am I doing something wrong?

[FaberAST]

USB input/output devices typically show up as two separate devices, one for input and one for output, each with the same name. There is a bug in the current version of SignalScope, which prevents the input device from being properly recognized. A workaround is to use the Aggregate Device Editor in the Audio MIDI Setup utility application to create a single virtual device, which includes both input and output of the USB device (Fast Track).

An update to SignalScope should be available soon, which will fix the problem.