Gentleman,
Having read your comments and what else I could find regarding DAC's selling for about $2-4000.00, I rapidly and unexpectedly purchased a used Luxman DA-06 because or its local availability, fine condition and reasonable price. Thus far the sound of CD's through-put by the Oppo 105d is significantly improved...the first time, in fact, that I found digital sound equal to or superior to that provided by vinyl.....I was almost astonished that 'red book' format offered such sonic quality. The high frequencies initially sounded diminished, but I then realized...my conclusion thus far...that flesh had been added to the Oppo's Sabre chips' thin sound throughout the audible frequency range, such that the highs and other frequencies were now accompanied by previously lacking harmonics.
The Oppo, for all its versatility, does not through-put DSD. For that a streaming device is required. Insofar as 'streaming' appears to be the 'wave' of the future I am moving in that direction. High end streaming/DAC/phono-preamp and pre-amp are now available as one unit...the new Levinson 526, for instance....but that
unit sells for $20,000.00, and many will, like myself, be more economically adding high end used electronics to existing equipment.
