Difference between digital/analo cables?

I recently purchased an Audio Alchemy DTI+ unit with digital coax input and output. Upon hook-up I had an extra Audioquest Quartz cable that I decided to try as the "coax" digital input. This cable is an IC for analogue purposes. It sounded great! I then decided to use a true digital coax cable (Ted's Excellent Cable). Upon installation, the sound had no where near the dynamics sense of space (this cable WAS broken in previously). I switched back to the AQ Quartz and it sounded great again! My question is: Are digital cables truly constructed differently than regular IC's? Could it just be that the characteristics of this AQ cable make it suitable for both applications? I'm not an engineer but I do trust my ears. I just don't know if a "better" digital cable is worth the investment. Any suggestions or insight would be appreciated.
Good observation.Treyhoss.In Stereophile mag couple of yrs.back they used AQ diamonds and pretty much said the same.The properties within are different.As a simular but different case I have theata data 3,It has a DD out. (Movie 5.1)It won't pass the signal using a reg aq ic nor a reg dig cable.It does pass using a video cable-An AudioQuest one.Strange A ? Your comparison cable ? Saw the movie, never tried the cable.Sorry couldn't pass that up.Had a dti,then the pro,then the pro 32 All were great.I also had the AA powered cables(2).I'm sure there is an engineering explanition for this 75ohm stuff.Just a hunch but maybe when you up grade further D-60's? Then there is the how much improvement/for how much money.
Thanks for the response. The cable going out of the DTI is the AA powered cable which has always worked well.AVGUY, Having owned the DTI+ - DTI PRO 32, did you find a huge improvement between each step? I ask because I'm considering the DTI-PRO which I hear is almost as good as the DTI-PRO32 (just older resoution software). I'll consider your recommendation on the D-60's, I've heard they are pretty good. Just FYI the Ted's Excellent Cable is made by a guy (Ted) here in Dallas - it sounds great at his shop! Anybody else have a similar discovery with IC cable?
Yo,there Trey.Ans:Yup. I only had the dti in my system a month or2.Wanted more,got it with each up grade. But,you are in a great possition. SKIP the AA path.Go directly to a Genisis Dig.Len.In these pages pro/32's go for about the same$(maybe+50 or so) If your system reviles enough.I've had speakers where some changes were more subtle.I now have aerial 10t's.And any one who heard genisis then AA would concur.(or they should get a boom box)When you get close to your purchase(if you do)seek out the model with heavy remote.There is an older model with a reg.plastic remote.Oh,did I tell you you get remote switching? Like if you have cd+dvd separates,or dig out on a satt. or cable box.But as they say you buy it for the sound.I payed what Audio Adviser charges for the powerd cables.I used those for couple of years. Nothing under 200 I ever heard came close.You have the ability to buy them used(sorry we're now talking d-60's)When you get there you'll see. Used d-60's go 165 +/- and are also worth the retail I payed.Lotta AA fans out there.If you sold your AA stuff you will get lots of response.