What do you mean by "memory player"? Is that a music server or a CD/SACD transport? If so, which one?
You're listing high end, so I assume a hi-rez source. I'd focus on DACs with open architecture that can handle sampling rates up to DSD one-bit, 5.6Mhz and everything from there down to 16/44.1. Though few have it today, I'd hope for an HDMI-in because more and more hi-rez sources will have that in the future. At a minimum you need Toslink and AES/EBU input and balanced analog out. A method to update firmware, such as USB, will delay obsolesence.
Dave
You're listing high end, so I assume a hi-rez source. I'd focus on DACs with open architecture that can handle sampling rates up to DSD one-bit, 5.6Mhz and everything from there down to 16/44.1. Though few have it today, I'd hope for an HDMI-in because more and more hi-rez sources will have that in the future. At a minimum you need Toslink and AES/EBU input and balanced analog out. A method to update firmware, such as USB, will delay obsolesence.
Dave