O.K., that was the short version.
My situation is a bit unusual in that I'm replacing an aging B&O 5500 two-channel analog audio system and Carver TFM-22 amp (both pushing 20 years of great service) with a system that will eventually (18-24 month time frame) serve as an audio and 5.1 (or 7.1) home theater system. I received my 990 today, and put it through its paces as an audio-only preamp with a single digitial input (basically as a glorified DAC and volume control).
The first rule of comparative testing is to change only one thing, and I broke it. With the B&O preamp dying right after I purchased my first "upgrade" amp (a stereo Odessey Audio Stratos Plus) to drive my front two mains, I ordered a 990 about three months sooner than I otherwise would have. This means two things: (1) if anything got worse, I could not blame it on a single piece of equipment without further investigation, and (2) the odds of things getting worse went up since there were more "new" things to contribute "trouble".
With that in mind, I configured the 990 in STEREO mode with two small front speakers crossed at 80 HZ to my sub, and ran some two channel PCM audio through it from a non-descript Sony DVD/CD/VCR playerusing an optical digital connection, via balanced outputs
(first time ever I visited a music store to buy cables), to the Stratos Plus driving my Bohlender Graebner Radio 520 L+R mains. The connection to the custom 96l sealed (Q=0.6) sub (Hypex HS200 amp driving a Daton Titanik Mk. II 12" long excursion driver) remained single ended.
If anything, the Sony CD/DVD/VCR transport reading CDs was likely the weak link in the system.
I found the sound a bit bright at first, but not so much as to be fatiguing, on Enya's "Watermark" CD. "Orinoco Flow" and "Storms In Africa (Part II)" definately seamed a bit bright. It wasn't so much bright as what might be described as an "American" sound compared to a darker "British" one. "The Long Ships" is a particularly difficult track, with 16 Hz bass notes -- I was interested in comparing the crossover in my active sub with that in the 990 -- I did not find the 990 deficient, at least to my ears.
Now, the Stratos amp has a reputation for being a bit bright until broken in, settling down in the first hour or so to "phase two" of it's persnickety "break in period". I listened for a total of four hours. If the system was indeed too bright, listening fatigue would set it... It didn't. Either the Stratos was settling down, or I was getting used to the sound, however the lack of fatigue suggested the former.
Time to stress the "bright" theory.
I put on Charlotte Church's "Voice of an Angel". A crappy system would butcher her delightful soprano in short order. Yet, "Pie Jesu, "Panis Angelicus," "Ave Maria" were rendered with a crispness and detail that was certainly no worse than my old system, and possibly better (not being able to A/B test much less double blind test, I am all too aware of the psychological bias to find the newest system "better"). There was certainly no fatigue. "Danny Boy" and "Amazing Grace" were equally satisfying.
Remember, I was replacing $5000 of 1985-7 hardware with about $2500 of 2005 hardware, including a run of the mill CD/DVD transport that would make the DAC in the 990 work for its money.
Clannad's "Magical Ring" was up next, with its combination of Gaelic and English folk songs featuring Maire Ni Braonain serving up haunting vocals. The best words to describe the rendition of "Theme from Harry's Game", "Tower Hill", "Seachran Charn tSail", "Passing Time", "Coinleach Glas An Fhomhair", "I See Red" (a favorite of mine), "Ta Me Mo Shui" and "Newgrange" was clear and detailed. It was almost as if the 990/Stratos was bright on American recordings, and neutral on European ones.
Stepping away from folk, a little closer to pop, with tracks from Clannad's "Sirius"" "Second Nature", "Turning Tide", "Skelling", "Stepping Stone", "White Fool", and "Something to Believe In" proved equally satisfying.
Returning to a domestic recording of Tracy Chapman's self-titled debut album, "Talkin Bout A Revolution", "Fast Car", "Mountains of Things", and "She's Got Her Ticket" appeared to dispel the theory that American recordings would be bright. Was the Stratos settling down, or was I lowering my standards? I certainly wasn't getting fatigued.
Where Brahaonain's whispy ethereal voice almost floats into the room, Chapman's deep soulful croonings grab one's attention. The 990/Stratos were equally faithful to both. Again, I noticed a clarity I did not remember with the older system/ Yeah, yeah, "buyer's justification". But, I was certainly not dissatisfied.
"Tyger" and "London" from Tangerine Dream's "Tyger" (basically William Blake's poetry set to music) continued the theme of clarity and transparency, this time with synthetic melodies, as did "Deliverance" from Vangelis album "Antartica".
Switching to classical, Wagner's "Die Valkurie" did seam just a bit muddied, but I remember always finding my self a bit disatisfied with that particular recording. I was about to switch to "Also Sprach Zarathustra" when my wife put an end to the listening session: "Don't you dare put on 'the theme from 2001' that loud!". It, was, after all, past midnight. At least she (a) didn't refer to "Die Valkurie" as the "chopper scene in Apocalypse Now" and (b) recognized that it was the same composer who wrote "Also Sprach Zaratustra".
So, from a purely subjective, non-double-blind perspective, what's my verdict?
The 990 serves as a fine $1100 DAC and volume control. Everything else is gravy.