Apple TV and Brightness

I recently purchased a new Apple TV gen 2 and have ripped a lot of my Cd collection into iTunes in WAV format and have it running to an external DA converter using an 'acoustic research' toslink. It was the only toslink I had lying around from their 'master series'.

After doing several A/B comparisons back and forth between dedicated transport (using a Moray James digital interconnect) and the Apple TV I was under the impression there was very little if no difference. In fact I thought the Apple sounded better in some respects.

Fast forward a few days later and I've noticed a thinness to the sound, the high frequencies are there but it's rather harsh, almost like it's shouting at me and not as even keeled. The bass seems to be leaner as well. Am I realizing I made a mistake or perhaps through cabling can I tone things down a little bit?

Any suggestions? Would a different toslink help? Another crazy idea I had was to get an Audioquest NPR power cable for the apple TV? Are there any gains to be had based on personal experience?
My ATV 2nd Generation sounds dry, lifeless and unlistenable compared to my CDP. This was from day one.

I tried two different toslink cables hoping to cure this with no luck. One cable (glass) accents higher frequencies but the overall sound is still very dry with either.
I'm not familiar with your DAC, but in general, and in my experience, Toslink is not the ideal interface for streaming digital content to a DAC and if it's the only option on the ATV that may be a weak link you will not be able to overcome. If you are interested in an alternative I'm having very good luck with a Squeezebox Touch via SPDIF. If I swap to Toslink on my DAC it definitely does sound inferior (a bit flat, lacking soundstage dimension, and lackluster in comparison). YMMV.
Its the jitter. The only way to improve it is to reclock externally or replace the clock inside the ATV, as well as improving the power delivery circuits.

Steve N.
Empirical Audio
Post removed 

Do you offer mods? If so at what cost?
Do you offer mods? If so at what cost?

His PaceCar does an excellent job to my ears. It yields an audible improvement in my friends system. If you decided to go a different direction with the source you could still use the PaceCar.
I have the ATV gen 1 and haven't heard the gen 2, so take this as you will...

I went from a fiber optic toslink to an inexpensive glass cable and noticed very good changes. Everything was more focused, less blurred. Everything got better, but that was the most obvious to my ears. The cable I bought was the Sonicwave glass cable from Amazon for about $25. Very happy with it.

I also added the Audioquest C7 cable - the cheaper one - and the same gains. Not sure if it reduced jitter by better/cleaner power, but it just sounds better. V