I agree with the others, this sounds like the pc 'being weird' and not the gamma1.
I can't think of a single explanation for why one input method (usb) would sound diff than another (spdif). there is no eq-ing going on in the dac and noting to change freq response based on input type.
for grins, if you can, try to locate a linux boot cd (ubuntu for example) and see if you can verify the hardware entirely without windows. the linux box should see the audio 'card' but NOTE! do NOT us a usb hub when you use unix and a usb sound card! that's a known problem for some reason (hubs interfere). go direct to the back panel of the usb port, plug nothing else on that usb segment and see if linux has that 'bass problem' via usb or spdif.
I'm willing to bet there are windows settings that are not 'cleared'. you could also trying going to the control panel in windows, deleting the device, removing it from usb, rebooting, reconnect the device and let windows rediscover it. that sometimes fixes 'stuck settings' inside windows sound system.
I can't think of a single explanation for why one input method (usb) would sound diff than another (spdif). there is no eq-ing going on in the dac and noting to change freq response based on input type.
for grins, if you can, try to locate a linux boot cd (ubuntu for example) and see if you can verify the hardware entirely without windows. the linux box should see the audio 'card' but NOTE! do NOT us a usb hub when you use unix and a usb sound card! that's a known problem for some reason (hubs interfere). go direct to the back panel of the usb port, plug nothing else on that usb segment and see if linux has that 'bass problem' via usb or spdif.
I'm willing to bet there are windows settings that are not 'cleared'. you could also trying going to the control panel in windows, deleting the device, removing it from usb, rebooting, reconnect the device and let windows rediscover it. that sometimes fixes 'stuck settings' inside windows sound system.









)






