Toslink VS coax VS other forms of Digital transfer

Thanks so much for the clarity… I am primarily a CD guy…

I recently purchased an Audio Research Ref CD9…  I know it has no SACD but neither do I…

This is the deep end of the pool for a CD player and DAC to be sure… and far over my projected budget too… but…  

OMG!!!…   It has a totally seductive and emotive sound quality… amazing detail and more depth than I have never heard from a CD player… reminds me of the ultra clean yet extremely musical sound of an analog studio master…  very mesmerizing for me, I've only had it a few days and I am stunned by how my old CD's that seemed to have been poorly mixed come alive and the ones I thought were well made are astounding! …

Geez… I am a long retired AV system designer and rarely am I so impressed and yes, seduced, by a new piece of gear… 

I am also experimenting with various cables like the Shunyata research power cables, another new world for me… I ignored the AC issue for years… for me no hum or noise, no problem… I was wrong.   

I like buying American products and love supporting home grown, hands on, companies like ARC and Shunyata when budget allows… any thoughts regarding digital sources are also appreciated.

I understand internals of the ARC Ref 9 to be similar to that of the ARC DAC 8 supporting CD, RCA, USB, AES and TOS… I am not decided on which inputs are best used for what yet, so that is my current quest… still perusing the the owners manual.

I am LOVING the ARC Ref Cd9, probably not using it to its full potential when it come to the DAC.  I play mostly CD's and I just ordered a Quantum Blue fuse for it since that is one of the last pieces in my system not to have one installed.... Crazy this hobby can be... I never would have thought a fuse makes so much difference...

I prefer to use the upsampling function with the softer filter slope for my CD listening... went there, liked it, stayed with it.  I will also mention here that the break in time for ARC components is truly around the 500 hour mark and that includes new stock tube changes in my preamp which came with new ARC tubes although I purchased it here on AG with 4500hrs on it.  It was like at the 500 hr mark for the new tubes everything got a to another level of depth, detail, clarity and sweetness.  I was surprised as it evolved from great to fantastic! The SR Quantum Blue fuse came along and another layer of depth appeared especially in the bottom end after maybe 20 hrs although the 1st level of improvement was immediate.

For the CD9 I am using a Shunyata Research power cable, Zitron I think, the size of a garden hose but lot more expensive... and Cardas Clear RCA 1m cables for the interconnects to my ARC preamp.  

I have experimented with XLR cables too, however, I keep coming back to these possibly because with the 6db lower single ended outputs of the RCA's, I can better use the fuller range on my Volume Control...

So far as the DAC goes... I have experimented with the optical out from my Bluesound Vault 2 with some sonic improvement off the hard drive but I use the Vault as a Juke box source and tuner/streamer not for hard core serious listening and have never put in extended hours of trail and error A/B listening to determine the real differences.  I have heard there is an updated version of the Vault 2 with better internal components so that could be a game changer at some point too.

I also have Cardas Clear Light RCAs (cheaper than the Clear) running to my preamp tuner inputs from the Bluesound which were a big improvement over my previous interconnects.. I apologize, I don't remember what those were at the moment. 

I am music lover, musician and a life long audio hobbyist so I keep things changing as I feel the mood and have time to experiment.
Hope that helps!  Remember... Enjoy the music!