Set up: Eastsound CDE5>zhaolu2.5C(amp upgrade)>audioinnovations valve amp>quad ESL57. I connected the coax out of the E5 to the 2.5C and the analogue outs of the 2.5C to my amp. I also connected the rca outs of the CDP directly to the amp so I could compare easily.
My initial impressions after maybe 24hrs run in:
Almost impossible to tell the difference between the CD-E5 and the 2.5C. Maybe the bass is a little lighter on the 2.5C, but only its something that was maybe noticeable in some tracks but not in others. Spatial info was just the same, depth just the same and tonal presentation is also just the same. In short, if you own a E5 then this DAC will give you the same sound signature. Please bear in mind taht this is only after 24hrs, also I leave my CD-E5 on all the time as it makes quite a difference to the sound, so I am going to try the same with the 2.5C. Also note that the E5 also has a CS dac in it (CS4390) - not the same number exactly as the 2.5C, but fairly close. The DAC probably needs more burn in time and more power on time to really assess it, but right now, I'm really glad I bought the C version because I am very fond of the E5 sound.
The headphone amp: My point of reference is the LD2 with HD650s. I would say that the amp is not quite as good as the LD2, but again, its a close run thing, and could easily be described as a valve vs. SS affair. I would say bass is not as copious, but is tighter. The overall sound is probably a little more hard, but maybe if you're used to listening to SS all the time then its normal - bear in mind I'm listening through valves all the time, although I would have said that the LD2 is pretty neutral. It has plenty of kick to drive the HD650s, and on relection I might say that the little bit of brightness/harshness might just work to your advantage if you think the senns are a bit veiled. Again, I reckon it probably does need more burn in/power on time, so again, I will listen again critically in a few days and see what happens.
Now on to a question for those of you with the 2.5 - Do any of you leave it powered on all the time?
Oh yeah another thing, I am using my own power cords on everything, which lend quite a bit of clarity to each component I've tried them on, but didn't listen to the 2.5 with a normal cord so don't know the benefit there. I also use my own silver interconnects, some with standard rca plugs, some with eichmann bullets.