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In use. The only possible points of contention are four. One, the ±6dB balance control has no center indent. This should bother only career analists or those too lazy to return to zero manually. Two, the XLR and RCA outputs can't be used together. This one folks with XLR-only amps and RCA-only subwoofers will feel. Three, the home-theater bypass loop is specific to XLR to likely reflect that balanced outputs on surround-sound processors have become more ubiquitous. It simply leaves out those without. Four, the power umbilical on the external PSU exits in the front. If you mean to place the PSU next rather than behind the Jazz, you'll be looking at bits of the umbilical. This seems strangely inelegant for a machine which clearly benefited from tremendous attention to detail.
with optional footers and two-tier elastomerically decoupled VFS platform
An impeccable high note of the user experience is the remote control and volume control's chosen gear ratio. Each press of the up/down buttons elicits a confirmatory very sensible yellow light on the Jazz to let you know that the command was received and the wand's battery and your aim are up to snuff. Now the volume control moves by such a tiny amount that over/undershooting the desired level becomes essentially impossible. In short, the range of minuscule adjustments achievable from the seat is tremendously broad. That's thrice relevant because the Jazz remains brilliantly intelligible into levels barely above whisper to explore room for midnight sessions usually neglected. The wand's angle of infrared reception is fabulously endowed as well. Being 60° off-axis caused no misfires. As such interfacing with the Jazz from the listening seat was the stuff dreams are made of.

If you've never owned or handled a Nagra before, you'll be positively tickled by the response to the wand's on/off and source selection commands. Unlike nearly every other firm which employs invisible relays, Nagra turns their big block control mechanically and does so with a satisfyingly fat click. It's an obvious bit of exhibitionism for the company's well-documented acumen to execute mechanically trick devices with legendary Swiss precision.

Audible excellence. If I only had one word to condense my first impression, it'd be space. The Jazz excels at space in all directions. On layers it's like a hand-made Pâtisserie Boulangerie Blé Sucré croissant. That seems à propos given Nagra's location in Switzerland's French region. But it's not simply a function of overall expanse. It's accompanied by a specific quality. Exactly like a Rethm widebander whose Indian designer pursues what he dubs the 'spark of life' from unobstructed fully liberated overtone action, the Jazz aces billowy airiness and reflective venue cues. It's a big light-filled show buoyed by elasticity and subtle textures and seasoned with dimensional MSG for very tactile contextual contrast.
with Swiss soundkaos Wave 40 speakers, Zu Submission subwoofer and FirstWatt SIT-1 monos
If I only had two words to capture my second impression, it would have to be noise floor. Think a few subterranean levels below ground. This becomes most self evident with reduced volumes. The extent to which you can zoom out as though you were walking backward and away from the performers is stunning. Remaining connected has you zoom back in not physically but solely with your hearing attention. This ability to return purely with your mind's eye and still see it all at minimal loudness is directly proportionate to the machine's exceptional S/N ratio. Though Marguerite Kudelski is an equestrian, her Jazz isn't a horse but tube whisperer. This could fly in the face of expectations which associate Nagra's house sound as voiced for beauty over ultimate accuracy. Whilst the Jazz clearly lacks the dryness many relate to transistors, its ability to drill down on micro detail competes with powerfully microscopic semiconductor units.

In that respect the Jazz is far more modern than the previously reviewed PL-L. Make no mistake, beauty remains. The lens which captures it simply no longer applies deliberate leading-lady soft focus. Even so there is softness. But it's not from response deviations or obscured detail. It's textural. Rather than carve out transient emphasis which telegraphs as vigorous, choppy, spiky, needly or energetic, the Jazz is mellower and more decay-centric. It celebrates wafting undulating fluidity. Yet it's decidely not thick. Again it's the Rethm aesthetic. It would collapse upon itself were tone density set too high to overshadow upper harmonic finesse and inside-out illumination. The upshot is an attractive slightly beautifying treatment that's spatially cavernous in the very best sense, manages micro detail in a way which defies the analytical and remains lithe and supple throughout. It's a perfect distillation of what a modern valve preamp might be.
The earlier criticized umbilical orientation of the PSU - why not have it come out the back for a cleaner look?