Tuatara / JonL
Thanks for the warm welcome.
Trying my best to answer your questions - my thoughts . . .
ATH-W1000 w/ Yamamoto
IMO, the Yamamoto works best with the W1000 and vice-versa in the sense that the W1000's didn't do it for me with the other amps. Having bought the W1000's before the Yammy, I was actually thinking of selling them. They were very good with my other amps, just not great. With the Yamamoto, it becomes really clear as to why some really like the W1000's. Without trying to exaggerate, the clarity and synergy of the W1000 and Yamamoto is scary good.
Srajan is 110% correct when describing how well they work together. IMO, they have the best synergy I've ever experienced between two components-period
- perhaps it's the (Japanese) way both are voiced? While they don't hit the lowest octave, what they do, they do sublimely. Detail is eye-opening. The decay of notes is amazing, something not experienced to the same degree with the other amps. Like Srajan posits, sound rolls out like spring water, pure and clean, almost sounding unamplified. Soundstage with this combo is very precise and focused - it's very easy to pick out where voices / instruments are in the mix. Best music with this combo - Solo vocals and instrumentals / fast paced pop (as long as it's not too bass heavy) / easy listening.
ATH W1000 w/ Cayin HA-1A
I found the W1000's with the Cayin to sound a bit too etched for my tastes. On my PS Audio GCHA, they sounded just too hard/cold. Despite the fact that you can match adjust the impedence on the Cayin, this combo never seemed to gel to my satisfaction. That said, the Cayin, in Triode mode, was the best with the W1000's.
AKG 701 w/ Yamamoto HA-02
IME, the 701's at lower volumes and soft music they were OK on the Yamamoto, however, for quicker tempo / rock, the Yammy just did not seem to have enough to drive it at the lower levels/octives. I found that for rock and classical, things sounded a bit dark. Though, if I hadn't heard the W1000 and the Yammy, it probably would have been less obvious.
AKG 701 w/ Cayin HA-1A
The 701's shine with the Cayin due to the sheer grunt it puts out in ultralinear. A lot of folks seem to like the Cayin in Triode, but for my taste, ultralinear was best with the AKG 701's. While this combo didn't have the same degree of detail as the all Japanese combo, there is quite a bit of detail. Sound is very balanced with a degree of warmth. Soundstage is broader and more extended vis a vis the ATH/Yammy. Best music with this combo - classical / hard rock.
In short, given my tastes and experience, here's how I would pair things:
ATH-W1000 & Yamamoto HA-02
AKG 701 & Cayin HA-1A
Senn HD650 & PS Audio GCHA
In my opinion, these amp and cans pairings have the best natural synergy that seems to complement their respective sensitivity & power, detail & soundstage, and voicing & range.
Hope this helps.
PS - Haven't done any tube rolling with the Cayin yet - perhaps this will affect my findings - I'll keep you posted.