OK, got off work early today and Ori came over and we did a massive all-Zhaolu shootout. Here was the gear:
1. My Zhaolu 1.3, PSU upgraded, headamp disconnected.
2. My Zhaolu 2.0, CS Dac, upgraded Blackgates from Eddie, headamp disconnected.
3. Ori's Zhaolu 2.0, AD Dac, upgraded Blackgates from Eddie, headamp disconnected, XLR's disconnected via resistor mod (see prior post/pic in this thread from Ori), DC blocking caps removed (also see prior post/pic from Ori), coax switch soldered into on position (front panel lights unplugged, permanently in coax input mode, also see prior Ori post regarding this mod).
4. Ori's Zhaolu 1.3 with opamps removed and Ori's own discrete output stage installed.
Opamps were the same in all units: opa2604 in lateral positions and DY2000 in the center. Power cord was the same, Signal Cable Digital AC. Coaxial cable was the Oritek X-1. We were able to easily swap CS and AD Dac modules between the 2.0 units as well when we needed to. We used my Squeezebox 2 as a source, and my speaker rig.
Here are several of our impressions, prefaced by the fact that although we agreed for the most part, YMMV and these are our personal impressions only:
Briefly, we agreed that Ori's modded 2.0 had better treble detail and extension when compared with my unmodded 2.0, using the same Dac module (the CS dac for this comparison). We concluded that clipping the XLR resistors, removing/bridging the DC blocking caps, disconnecting the front panel lights/switches, and bridging the coax switch to permanently "on" was a worthwhile set of mods based on our listening. We previously determined that coax is quite superior to optical, and so permanently deactivating the optical input didn't seem like much of a price to pay for better sound.
Moving on, we then compared Ori's modded 2.0 with the AD dac to my Zhaolu 1.3. Very interestingly, they sounded nearly identical...we had a very hard time telling them apart, whereas we could easily tell the modded 2.0 from the unmodded 2.0 when they were using the same DAC chip. So our conclusion was that, after the modifications, the 2.0 closely matched the 1.3 when all else was equal (AD chipset, opamps).
We now compared the AD to CS Dac chipsets. Where we agreed: they sound quite different, with AD having greater treble extension and "openess" but CS having a smoother sound overall and (I felt) greater warmth/bass presence. Where we slightly disagreed was which we preferred: I gave the edge to the CS as being less fatiguing and smoother/warmer; Ori preferred the detail and extension/openess of the AD. We concluded that perhaps which DAC one chooses will depend on personal preference and system syngery for this reason. Perhaps solid state may mate better with the CS for example; again, YMMV.
Finally, we listened to Ori's discrete-output-modded 1.3. This was the clear winner overall. Better treble extension and detail, tighter bass, even more well defined soundstage. But we agreed that the other units sounded damn fine; this mod just took it another level up from an already high starting point in terms of musicality and sound quality.
So we had a good time and generally concluded that the Zhaolu 2.0, when modded, sounds at least as good as the 1.3 and allows for rolling of DAC chips. The choice of DAC module should be based on personal preference/ auditioning if possible.
I quickly performed surgery on my 2.0 with CS dac, and did all of Ori's mods: the result--> a fine sounding dac. If I can do these, anyone can.
One last note for squeezebox owners: we compared the squeezebox as a transport to my Panasonic DVDS47, and we were amazed by how much better the squeezebox sounded! Compared to the Panasonic at least, the squeezebox is a fantastic transport.
