Stretch wrote:

Am I correct that in order to get that HQ output you have to use a 24-bit software player with 24-bit sound card drivers?

On the AWE32 PC, playing the music? No. Basically MIDI song says the EMU chip to play samples and it will do that and mix all together and that resulting mix is done within the limitations of the EMU chip.
If it is 18-bit then fine. So any MIDI player will work.

On the recording PC, you'd have to force it to record 18-bit samples, no matter what the metadata on SPDIF channel status says about the sample length. Also the recording PC should then be locking itself to incoming sampling rate so it does not resample that to it's internal clocks before recording.

Basically, all SPDIF interfaces are 24-bit links, but for example playing a CD that has only 16-bit samples will result into SPDIF having 16-bits from the CD and the rest being zero (or garbage?), and metadata saying that the samples are supposed to be 16-bits so the next device won't try to process/record/play unused zeroes or garbage.

Thanks for the reply. My Mac mini does have the ability to lock on to the SPDIF signal, but I don't know if it is bit-perfect and also I can only select 16, 20, and 24 bit for recording bit depth, so I will record at 20 bit / 44.1 kHz.