What does the stereo up-conversion feature do?
A. The Model 990 converts the sample rate of the left/right front channels of digital audio sources from 20 bit/48 kHz to 24 bit/192 KHz. Contrary to some audio myths this does not increase the resolution of the recording as you cannot create bits where none existed. However, what it does do is move the audio portion of the signal away form the brick wall filter that is usually present at 22 kHz. Without getting too technical, these filters often affect the phase integrity of the audible high frequencies. An up-sampled signal helps to restore the proper phase relationships of these extreme musical highs. This feature is particularly valuable for those with high-resolution loudspeakers, where you will hear a discernable improvement in the top end.
