David,
I have now owned and auditioned a Bryston BDA-3, Luxman DA-06, and the Oppo 105d with its internal DAC. Each, as you know, uses a different DAC chip: respectively AKM, Sabre Burr- Brown.
I now use exclusively the Bryston, sourced via USB by a Bryston BDP-3 streamer, or the Oppo disc player via HDMI.
The characteristics of these DAC's has been described by others, and there may be general agreement that the Luxman is 'very smooth', the Oppo (sabre) detailed but harsh, the Bryston in-between.
My personal impressions:
1. The Luxman employed for chamber music...string quartets, piano trios and quartets...
is 'muddy'....the lack of detail increasingly becomes annoying. Its employ for solo piano invites similar comment. Try as I might to persuade myself that the 'more expensive sound'...ie, the Luxman's...should be better than the Oppo's, I had to throw in the towel and
avoid the Luxman for strings and piano.
2. The Luxman employed for voice is a delight. I've read of various hi-fi components
that a 'smoother' high frequency response decreases listener fatigue.
Such comment applies to the Luxman used, for instance, for listening to an
opera DVD.
3. That virtue is such that even 'downrated' DVD audio sourced to the Luxman via the Oppo's coaxial audio output was superior to the Oppo's internal audio decoding of opera DVD's,
including blu-ray DVD's.
4. The Bryston BDA-3 is a good compromise...'
I struggled to parse the foregoing impressions in respect of digital source format...standard CD, SACD, hi res PCM, double speed SACD. The sound quality seems to improve as one progresses from the beginning to the end of that list, but the DAC comparisons...at least my ear...are the same.