wpines...i have not heard any Mac gear so I can't comment on the combination but to my ears the ARC Ref 3 is a very neutral sounding tube preamp with low noise floor, highly resolving, and flat tonal balance. No lush sounding tubiness here if that's the sound you are looking for. It does what tubes do well in spades and that's provide a wide and deep 3D soundstage with fleshed out images. Images are not flat or thin but have body and resonance. I used to have the ARC LS 26 which had all the same qualities but the Ref 3 just took those qualities and bettered them by a few notches but they are both excellent. I have not heard the Ref 5 yet but it seems that has clearly upstaged the Ref 3 on all these counts. Some people find the bass in the Ref 3 (and the Ref 110 - the first of 3 power amps in the Reference line) as being a bit lean.

Hope this helps. Will you have a chance to try the Ref 3 in your system? At the end of the day that's the only way to assess how it will sound with the rest of your system. Good luck.

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Cyril
Speakers/Amp/Preamp: Thiel CS2.4 / ARC Ref 110 / ARC Ref 3
Sources: Basis 2001/Graham2.2/Nagra BPS/Benz Micro Glider SL, ARC CD7, Oppo BDP-83 SE
Cables/Power/Other: Nordost Heimdall ICs, SCs / Shunyata Hydra 8, Shunyata Python Helix PC / VPI 16.5, HRS Nimbus isolation system