I posted this in the hardware section, but with this Octa-Capture thread and the posting of the updated drivers, I'm also posting here. Along with Win 8 support, the 1.5.1 drivers have been updated for Win 7, which I have.
My hardware section post:
I downloaded the latest 1.5.1 driver for the Octa-Capture and installed it. I used it for the first time this morning on some previously recorded material in Sonar. I was getting some distortion on the singer that seemed to be caused by the bass track, that I never had before. The Vocal track without the bass track was OK, the bass track by itself is OK, but with the two there was distortion (intermodulation distortion).
I tried several things and then remembered that I had upgraded the Octa-Capture driver. I uninstalled the 1.5.1 driver, restarted the PC and then installed the 1.5.0 driver. Loaded the same Sonar project and no more distortion, "intermodulation distortion" or low frequency distortion - what it sounded like.
I haven't tried reloading the 1.5.1 drivers (which I will do at some point) to see if it is the driver
UPDATE: Reloading the drivers has fixed the problem. If anyone else runs into the "distortion" problem with the 1.5.1 drivers, uninstall and reinstall, and if it worked like mine it will fix it.