Received my WA7. Thought I would add my initial observations:
Temperatures were measured with a Fluke 62 Max+. Maximum temperature degrees C scanned in given location noted.
Ambient: 19.2 deg C
Minutes Supply Case Tube
0 19.2 19.2 19.2
20 25.0 21.3 62.5
40 29.8 25.5 66.5
60 32.3 28.1 69.6
80 33.2 29.3 73.0
100 35.5 31.9 73.3
120 35.6 32.6 73.5
180 36.9 34.7 74.4
240 37.4 34.8 76.1
So far I have listened with both hifiman HE-500 and Beyerdynamic T90. Things are still changing as the stock Sovtek tubes settle in. Initial Impressions after 6 hrs:
Silent background
Solid bass with clarity, impressive transient capability
That tube magic midrange
Impressive clarity on the high frequencies
I was on the fence about selling the HE-500. They are competent but never really sparkled on my other amps (WA3+, V200, O2, DAC-1.) They seem to have come to life on the WA7. They stay while I listen longer and evaluate this combination.
As each to his own on their search for sonic utopia, I must say that if I was told I could only have the WA7 and the Beyer T90, I would indeed be happy to listen to my library, enjoying the music quite well. In fact the danger of this combination is losing oneself in the music and forgetting time. A reminder that my preferences and auditory canal resonances are such that given the Sennheiser HD600 and HD650 I would choose the HD600. YMMV.
