what are some digital cable upgrades/servers?


I just installed a Qsonix music server into my system. My system has: Meridian G-68 processor; G-98 DVD/CD player; MBL 111e's mains; Aerial CC5 center; MBL 8011's monoblock main amps; Sunfire 7x400 for center; rears; zone 2. Harmonic Tech speaker cables; ps power cords and Shanatu;
At first I had Qsonix configured for analog out into Meridian; sounded horrible; changed to digital output of server into Meridian; and it sang great. I am using stock digital cord that came with unit. Has anyone found a great digital cord to connect server to processor that has a noticable improvement; that costs less than $500? what about it helped improve sound stage and detail? Other brands auditioned? My music tastes are eclectic; jazz; vocals; pop/rock; classical. By the way; the Qsonix with its touch screen has been fantastic; easy to set up and easy to use; wife likes it...sounds almost as good as native system...
Thanks for your suggestions...
mribob
75 ohm digital cable with rca pin...not toslink. I have to admit my ignorance; don't know difference between s/pdif; and aes/ebu; please explain what this terminology means; and differences... I'm looking at the Harmonic digital magic II; lists for $500; can find on the 'gon for $300; but the eagle eye also caught my eye....I appreciate your response and help.
75-ohm with RCA pin is S/PDIF; I'm no expert so I cannot tell you the diffs at the cable/specification level.

I've listened to the Harmonic and several other 75-ohm cables before; in your price range,
I'd suggest the Eagle Eye. You'll be amazed at the musicality, imaging, etc...you get from it.
Bottom-line, to me, it doesn't sound like a digital cable.
I am one of the owners of Qsonix if you use a good dac the digital cable becomes less important. I can reccomend some dacs if you need some help