Originally Posted by Mudge
The G68 rolls off the mid-highs and emphasize the bass. This is to be expected, since most upsamplers don't have a flat frequency response.
Can you explain this. How does the upsampler know it is upsampling a 200Hz signal as opposed to a 2000Hz signal? I thought upsamplers simply calculated the approximate value of a sample between two real samples. If it is easier, you could just direct me to a white paper that explains it. Thanks.

561, DSP5500s, DSP5000C, analog sides and rears