Ecamel, I used to have as my digital front end a ML-31.5 transport and ML-360S dac. It was quite good, but was vastly improved sonicly in all areas by adding the DCS Purcell, without the firewire, to up sample to 24/96. I kept this digital front end for over six years, until I finally found other digital gear, I only care about redbook, that out performed this setup in my system.
I highly recommend you try to audition the Purcell in your system, it will give a much higher level of performance then you have now. Their are four different filters that you can choose from with the Purcell, I found on all music that filter #4 was the best sounding/performing in my system.