OK, so I spent the past few hours listening to my favorite tracks via the AudioZone DAC1 as an outboard DAC to the Duet and I must say the difference is big!
The DAC does not have a chassis/housing and is a fully exposed unit. Like the top part of the image
Tracks used for testing:
1. Dire Straits - Private Investigations (for the bridge)
2. Metallica - Enter Sandman (nuff sed!)
3. Norah Jones - Chasing Pirates (female vocals)
4. Leonard Cohen - Waiting for a Miracle (male vocals)
5. Pink Floyd - Shine On You Crazy Diamond (imaging and soundstaging)
6. Sukhwinder Singh - Omkara (hindi music)
7. Jagjit Singh - Yeh Daulat Bhi Le Lo (male vocals)
8. Mussorgsky - Night on a Bare Mountain (rousing classical)
9. Clint Mansell - Lux Aeterna (less rousing piece)
10. Dire Straits - You and Your Friend (guitar)
11. Joe Bonamassa - Black Lung Heartache (blues guitar riffs)
12. Donald Fagen - Morph the Cat (bass line. DAMN!)
13. Tom Petty - Saving Grace (rock n roll)
So, as you can see, the variety is there. The main improvements I noticed were:
1. Bass performance - the lower end sounded more musical, tighter and much more resolved.
2. Overall slam - the overall sound reproduction had MUCH more detail, resolution and BODY.
3. Overall refinement and musicality - I wanted to listen to more music with the DAC1 plugged in. After an hour or so, I switched back to the Duet's DAC and the difference was more noticeable than before. It sounded like the edge had been taken off.
Now, I will say this - it took a while for me to start appreciating these changes. Some of these songs I have heard hundreds of times before and I found them to be even more involving with the AZ-DAC1 but the difference is not night and day. Nor do the improvements jump out at you. A fine testament to the onboard DAC. Also, I have a Duet and have heard that the Touch has an even better DAC.
In summation, quality of music reproduction
can be improved but the on-board DAC is a gem!
Associated equipment (with due respect to Stereophile):
1. Odyssey Syren Extreme loudspeaker
2. Audio Analogue Primo Cento hybrid integrated amp (100wpc)
3. Einstein Audio ICs
4. RidgeStreet S/PDIF cable
5. Usher Rapport speaker cable
Thanks go out to RoC for lending me his DAC, S/PDIF cable and ICs.
Let me know if you guys have any questions.
Cheers!