PranaFidelity and Atma-Sphere

Named for the God of Wind, PranaFidelity's new 94 lb, Vayu/fs, two-way, quasi-line–array loudspeaker ($6950/pair), which has a claimed frequency response of 29Hz–22kHz, an 8 ohm impedance, and 89.5dB sensitivity, was reproducing the exceedingly warm sound of Atma-Sphere's M-60 Mk.III.2, fully differentially balanced class-A, triode OTL monoblocks ($7200/pair) and MP-3 Mk.III.2 preamp ($5600–$9000, depending upon options).

It got more than a little difficult trying to figure out what was going on as PranaFidelity's Steven Norber buzzed around, turning on and off the Vayu/fs speakers' high-end tuning circuits. Nonetheless, I could admire the very nice sound of a triangle on a classical LPs, and the tweeter's equally superior performance on a piano recording by Jessica Williams. Is the speaker's bass a little hooty, were the amps having difficulty controlling their low end, or was it the room that created both the hints of hootiness and the booming? I look forward to hearing the speakers again with more neutral electronics.

corrective_unconscious's picture

Describing the Atma-Sphere product as that inaccurate usually brings out the aficianodos to object, if not the maker himself.

Tesla one's picture

From what I've read it seems surprising if OTL amps from Atmasphere were indeed "loose" in the lower octaves - reviews from around seem to indicate the opposit, especially compared to tube amps with output transformers. In any case, perhaps more stiffly suspended, and highly efficient hornspeakers would be a better match with the M-60's, which could, in a backward sense, point to a non-horn bias on the part of Mr. Serinus (and - apart from Art Dudley whom I railed against in his RMAF 2012 report of the Volti Audio Vittora's, and later him back at me in his final review of them - largely the rest of the reviewing staff of Stereophile); why end up concluding the electronics (i.e.: the M-60's) to be the less "neutral" part when the speakers and room acoustics are initially proposed as, and indeed very likely might be the source of bass problems as well? Why even pose the question when the answer is supposedly given to begin with? 

Steven N's picture

I have to take the sour with the sweet.

Needless to say, I very much appreciated Jason’s visit during THE Show and taking the time to listen.

I send him my apologies for losing my “yogic composure,” described appropriately in his commentary when I “buzzed around” in an attempt to change the sound for the better (via the circuit tuning switches on the speaker’s rear panel).

The system performed well during most of the event, however, the AC wall voltage would occasionally drop, and with it the performance of the system waned.

Ralph informed me he typically brings a large variac to protect against voltage drops, however, this year it was left behind.  Additionally, the preamp would normally have been fitted with step-up transformers for the low output moving coil cartridge mounted on the Kuzma tonearm, thus we were limited in our capacity to play vinyl at more realistic listening levels.

As fate would have it, both Jason and another reviewer happened to arrive at the same time, only to experience a sound Jason did his best to describe and make sense of—what at the time, I would have to say, a system performing, at best, sub-optimally.

Indeed, less than fifteen minutes following his visit, a pair of reviewers from Italy entered the room and heard a very different sounding system; one, it turned out, they would include in their “best of show” list.

Given these events exist for manufactures to put our best foot forward, it goes without saying, I felt disappointed when the system simply did not deliver the goods at a most inopportune moment.

I look forward to another go at it next time around. . .

Kindly yours,

Steven Norber