I have to admit I've never had so much fun evaluating equipment at home; these are both incredible amplification devices... I've heard the 400s driving Magicos a number of times, and every time they sounded absolutely astonishing. I've been avoiding to bring them home before I had had the chance to settle on cables and power conditioning. The below are my impressions based on both in-store and at-home auditions.
Overall, the 400s are amps for the history books and a Spectral lover's dream come true. While this remains an ongoing evaluation, you know what the audience does at the end of a spectacular performance...
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- Indeed, not lifting the ground on the 400s results in significant grain in the sound - ugly. Star-grounding at the power distributor worked well,with the rest of the gear
- There is a red switch on the input stage board of both that I think is configuring grounding techniques; I intend to play with it on the 360s and lifting their ground as well
- Without the grounding configuration the 400s require (through the preamp's interconnects), the grainy sound is really evident with large choral - very ugly, in fact
- What I had assumed to be euphonic colorations in certain sections of the midrange with the aging panels, are apparently turning out to be colorations of the 360s; these are evident usually with French horns
- However because of those euphonic colorations, the 360s can sound more impressive with certain music material, though still somewhat flawed if you listen carefully
- On the other hand, I have not heard such clearly rendered bass and midrange as the 400s render it. It is as close to perfection as I have ever heard it. Timbral accuracy is dead on, in the the vast majority of the spectrum, and there are no superlatives need to emphasize that. Because of all this, the 400s are even more impressive because they are a true reality show in that respect
- Timbral differences and euphonic issues are really evident as the performers play every symphonic instrument's compass in the LP below. Piano through the 400s (not really a strength in my system) is absolutely perfect on the Q7s. Strings have all the sweetness with the 400s.
- The MIT ZIII power cords also supplied for evaluation (and presumably used for development) suck the bottom end out of both amps; I went back to my Shunyata to get the authority back. The 360s are still more authoritative down low, but the 400s' bass is tighter
- With extremely complex signals, the 400s superiority is also evident, and they maintain their composure with no effort. What is truly jaw-dropping is their ability to maintain proper size relationships between different elements of the orchestra; case in point
- excluding ultimate macro-dynamics, this is the first time I have been able to successfully play the finale of Mahler's 2nd as it really sounds at Symphony Hall where, at times, the chorus overpowers the orchestra by a wide margin, and the at the very end, they, the organ and the orchestra are all clearly delineated with the all the drama of that movement - this is a case where the only missing pieces are a proper room and speakers to do the rest. The 360s come close, but because of their slight euphonic nature, they are just not as clear or as-equally dynamic. Ultimate macro-dynamics aside, this is a jaw-dropping reality show
- Overall dynamic headroom is a little higher with the 400s as well
- I preferred the single-ended connection over balanced (same MIT 50ic cable)
- Resolution is slightly higher from the 400s, and really evident in their exceptionally-clean rendition of depth and instrument placement within the soundstage
Overall, the 400s are amps for the history books and a Spectral lover's dream come true. While this remains an ongoing evaluation, you know what the audience does at the end of a spectacular performance...
BTW, that switch on the 360 is not related to grounding (the board says "Protection" on it)...
