Bob - you won't get 24 bits. It is called 24-bit but real resolution is most likely below 20-bits. Traditional (ladder type) converters don't get any higher than 18-bits because of component tolerances while sigma-delta variety won't get higher because of timing accuracy and noise floor (your 20 bit is equivalent to 120dB). Why to upgrade if you like the sound?
If you upgrade - have you considered DAC. I use jitter rejecting Benchmark DAC1 ($1k) with inexpensive DVD player (good tracking) and Mac mini server. I have also HDTV connected. DAC makes system transport independent.
If you upgrade - have you considered DAC. I use jitter rejecting Benchmark DAC1 ($1k) with inexpensive DVD player (good tracking) and Mac mini server. I have also HDTV connected. DAC makes system transport independent.