For a few years now I was building up and upgrading my home theatre. Every incremental quality jump was in response to the improvements in sound and picture quality that I was able to squeeze out of HTPC. I am still far from reaching audiophile/videophile nirvana yet, but my current configuration reached an important milestone. In order to determine just how high-end audiophile HTPC is Ive enlisted a help from Charlie Whitehouse who kindly offered to bring his Theta David II player over to my place. The comparison concentrated only on sound quality from CD sources. Following configurations were compared: Home Theatre PC is self built using Asus TUSLC-2 motherboard, Celeron 1.2Ghz, 512MB PC133 memory. Sound card is RME DIGI96/8 PAD. Connection to sound processor was via coax SPDIF using 10m standard video cable (HTPC and the HT are on different floors). HTPC operating system is Windows 2000 Professional SP3. Software player is Sonic Foundry Siren (now discontinued). All tested music was stored on a hard disk in Perfect Clarity Audio lossless compression. Cost of this configuration, including cabling, is sub £1,200 including the software licences. Theta David II is a current model (modified for SDI video output although that was not compared). Player was connected to audio processor via coax SPDIF using Transparent Reference Digital Link. Power cord was also from Transparent range. Cost of this configuration, including cables is over £7,000 (player is approx £6,000, coax SPDIF cable £750, power cord £250, SDI mod > £1,000). The rest of the audio system comprises Lexicon MC-12B, connected to active speaker from M&K, three MPS-2510P fronts (150W+150W amplification per speaker box), two MPS-2525P (180W+100W+100W per speaker) surrounds and MX-350 sub (350W). In total, there is over 2KW of amplification. Active speakers are connected via balanced cables from Studio Spares. Charlie brought several CD's of his choice and we used them in our comparison. Tracks that we listened were: Evelyn Glennie: Drumming Track 7: Sorbet No.3: UDU Trail Joshua Bell: The Kreisler Album Track 1: Praeludium And Allegro (In The Style Of Gaetano Pugnani) The Eton Choirbook: Music From The Eton Choirbook Track 7: Browne: Stabat Mater (Corrected) Mary Black: The Holly Ground Track 1: Summer Sent You Kiri Te Kanawa: Faure Requiem Track 4: Requiem, op.48: Pie Jesu The average listening level on Lexicon was -10db. DSP mode was Logic 7 Music. Charlie calibrated all speakers to 75db white noise level. We listened for a few hours switching from HTPC to Theta without any obvious difference between the two. Both Charlie and me have to keep looking behind us at the Lexicon panel to make sure which source as playing as there was no obvious or easily recognisable difference. After a while we did agree that on two tracks, Evelyn Glennie and Mary Black we can, in certain specific part of the track, hear a higher level of detail coming from the Theta player. Why did comparison turn out such a result? One obvious difference is in the length and the quality of the connecting cables (10m basic video cord connected HTPC vs. Transparent Reference Digital Link about 0.5m long). Another possibility is the audio quality of a standard CD is insufficient to fully reveal the difference between the two players. Third possibility is that the rest of the system is not high-end enough to properly differentiate between the two. Fourth: audio compression maybe not completely lossless. I am now convinced that a HTPC equipped with good professional sound card can certainly perform as (very) high-end CD player. It confirms the results reported by Bill Gaw in his review of audiophile merrits of HTPC equipped with M-Audio Delta 1010 sound card and a review of RME card by Stereophile Magazine and by Kazushi (Jam) Marukawa. Review of Theta David II can be found here. I wish to thank Charlie Whitehouse without whom this comparison would not have been possible. I also want to thank members of this AVForums and AVSForum.