The 566.24 would be the 24 bit version. The 565 has 18-bit DACs built in but will accept up to 22-bit input. You'd probably be better off running your Cryus Discmaster 8 into a 518 setting the 518 output to 22-bit. On the other hand, with what you'd pay for a 566.24 or a 518, you could sell your 565 and buy a 568 with 24 bit DACs.

561, DSP5500s, DSP5000C, analog sides and rears