• I am bowled over by the sound HP8 (re)produces. Totally dynamic, expressive, FULL-range (clearest, deepest bass that I have heard from an OTC / OTL tube h/p/a). The MZ3 betters the HP8 on a technical front; but the HP8 has more force, gravitas, heft in music delivery when those count.
• The MZ3 is excellent, with great airiness, detail, depth, soundstage on low-Z headphones in its own right. That is, in my mind, its favoured match.
• As for Woo WA6, I use the 1st Generation: with the 6DE7 sockets. I can employ adapters to permit the use of 6SN7 or 12AT7 tubes. The WA6 sound is greatly affected by the choice of rectifier tube. My favourites are Brimar CV1863 and USAF 596 (with Woo adapter).
• Do not let the “age” of the Icon Audio design put you off. There have been subtle / noticeable improvements over time. It
is the quietest OTC tube h/p/a that I have used. No hum! Plus, it takes a 6SN7 pair + a 12AX7 (or 5751 or 12AT7): none of these are esoteric types. To be sure, each category has its ‘holy grail’ members: these will be $$$$, €€€€, ££££ etc
.
• The ZMF headphones (and others) sound wondrous when driven by HP8!!