I hadn't thought of it myself....There was a
thread over at Audiogon about using an AVReceiver's internal DAC to playback hi-rez 24bit/128kHz files using a computer source along with an external amp--bypassing the AVRs preamp/amp. Since I have a similar Denon AVR, I gave it a go though not at that resolution. I used my MacBookPro Core2 Duo and iTunes.
Well it works.
It = Denon AVR4306 used as 24bit/96kHz DAC converter. Then the analog output sent to separate 2ch preamp + amp. My macbook pro max's out at 96khz--other computer systems may have 128kHz output. My audio system details below. I used Toslink from computer to Denon. I'd describe it as a moderately resolving, musical system.
Step one
Download hi-rez files or use 24/96 files. My post above. (free samples at hdtracks.com)
Step two
Download a FLAC to AIFF converter: Max. this allows 24/96 playback in iTunes (only on certain macs). Another option is the standalone FLAC player "Play. both are at http://sbooth.org/
Step three
Open Audio Midi Set Up Preferences (Mac OS 10.4)
**Close iTunes when changing settings in AMSU-settings may not change otherwise**
Confirm "Properties For" tab is set to "Built-in Output"
Change Audio Output to 96000Hz(or higher if avail) and 2ch-24bit.
Step Four
Launch iTunes. Listen...
My observation
It was a quick 1 hour+ session. I listened to both 24/96 and 16/44 AIFF songs in itunes, back to back. 3 songs played about 2 times each. I probably won't use the most standard terminology. I checked SPLs with both songs both formats were consistent.
Wolfgang Amadeus Mozart Violin Concerto in G major - Allegro24
Classical. Not familiar enough with this genre to hear nuances.
Misery - Dave’s True Story.
This seems to represent a favorite type of music of many audiophiles: female jazz vocals, acoustic instruments, and simple arrangement. The vibraphone/keyboard and drums were very defined and much more separated with the 24/96 version. Kelly Flint's vocals were crystal clear, conveying all of her sultry voice. The sound stage size didn't seem to change between the formats in my system.
I also listened to the 16/44 version of this song via my USB NOS tube dac (without the Denon in the chain) there was a noticeable difference in the weight of the music and midrange. The tube dac was not as defined as the Denon playing 24/96.
Lucia - Marta Gomez
This is Latin jazz. Very similar differences to Misery song mentioned previously. I especially noted the definition of the wood blocks was much clearer and almost creating a 3-D vision. In comparison the 16/44 version was woody but diffused.
It would be really cool to compare using songs that I am very familiar with but not readily available. Hi-res music could be addictive for those serious focused listening sessions on a detailed audio system.
As I said before, the amount of music commercially available in hiRes is very, very limited for my musical preferences e.g. indie, electronica, 80s and blues. Therefore, I am not planning on acquiring a hi-res setup at this point (plus my G5 normal music server is limited to 16b/48kHz). But it is fun to play around with it. Now, at least I know I can playback 24/96 with the gear I have already in case some music I am interested in comes along. I should add that I do know that there are a number of stand-alone DACs from entry level to premium which play all resolutions.
cheers, ed
