@all, thanks for every answer, folks !
@Srwooten: I will try to make an audition of PS Audio DS...
@B_limo: I asked this question to myself: is there a way to intercept the I2S path inside my Akurate CD/SACD and install an Amanero USB card, just for an example? Maybe yes, but I have not found any company or artisan to do so. So for the moment the idea is abandoned.
@Audioengr: Empirical Audio Overdrive... I evaluated also this option, because it seems a wonderful DAC. The problem is I cannot try it at home in Italy (like Lampi and others).
@Igator: Be sure the Akurate DS will be my option if I cannot find a DAC with the same sound as my Akurate CD. I don't say I want a DAC that perform better, because it depends on every customer's setup. At least I can convert my 40 SACD .iso obtained by ps3 with Saracon from DSD to 24/176.
My problem is the investment made in MacMini and other stuff, to be converted to a storage NAS.
Akurate DSM afaik is a preamp too, right ?
MSB Analog can be a good choice, I will try to listen it at home.
Just for let you focus on my musical taste: in this moment I'm listening a DCS Debussy. Not very good in my setup. Mid-bass too preeminent and overall not so much emotional, too prim, compared to Akurate CD.
Very good for jazz and some Classical, but with Rock/Electronica it is far from Akurate.
I'll send back to the shop asap ;-)