Theta Gen VIII MkII vs. ARC REF II Mk. II

Have heard both in the same system but not at the same time. They are very different. I own the Gen VIII S3. Actually a tube preamp with the Gen VIII gives the best sound. The Gen VIII provides very tight bass that a tube preamp might not otherwise have.

If you were deciding between one or the other, I would not know which to recommend. Either choice would be a trade-off in comparison to the other in some areas. If you listen mostly to vocals and chamber music, I'd vote strongly for the ARC Ref II MKII. However, if you like very dynamic music, the Gen VIII excels in this regard.

A friend of mine had the ARC Ref 3 mated to the Theta Citadel monoblocks. In an effort to move his system to a Music Server based system, he auditioned the Gen VIII. IMHO the Theta sounded more natural than the ARC, in his system. The only area where I thought the ARC did a bit better was in the midrange. The differences were very subtle though and unless they were compared side by side I don't think you would notice them that much. Again, this is all related to the sound in his system. YMMV depending on your associated equipment. As a pure DAC the Theta may be the best I have ever heard.

Good Luck.