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Off the menu. If you've read my Munich HighEnd 2014 show report, you know that I catalogued sound into two classes: musical and hifi. Whilst that could read inherently judgmental—musical good, hifi bad—it's not. Playback is purely auditory. Live music is multi-sensory. It's actually dominated by eye sight as the human animal's primary sense. Live concerts divide into acoustic and amplified. Both have characteristic sonic signatures. Compared to either, playback is tonally washed out and dynamically squashed. It's obviously scaled down too since our rooms wouldn't contain the majority of bands or orchestras we listen to. Compared to live music, what I call hifi sound because it fundamentally differs has far sharper image focus, soundstage specificity, layering, treble energy and separation. Much of it compensates for the lack of encoded visual data in our music. What I call musical playback focuses on tone density, colour saturation and LF mass as primary real-life qualities. In turn it gives up or lightens up on typical hifi aspects. Arguably most complete would be playback that's solidly grounded in the 'musical' qualities, then added extra-visual 'hifi' qualities atop without undermining the foundation. (Feel free to disagree with my scheme. It's here only to frame my comments on the review subject.)

In this context the Rhythm 1.1 focused on the musical foundation. It acted as substantiator, not aerator. My tone-wood soundkaos speakers focus similarly on tone and substance. Here their cubic volume and driver diameter sacrifice LF extension and power which is easily augmented with a good subwoofer if desired. On the other end the Raal ribbon tweeter crosses in at 8kHz to present a less brilliant informative treble balance compared to typical tweeters which are crossed over at 1kHz to a small 4-inch midrange. Meanwhile EnigmAcoustics' Mythology M1 super monitor with ESL super tweeter is an aerator par excellence. Whilst I've never yet heard performer halos or individuated space bubbles live, if recording artifice contains them, this speaker maximizes their recovery. In my scheme that's hifi sound albeit at a very elevated artful seriously impressive level. "I can see sound" is the primary and far from subtle effect.

Playing the Rhythm 1.1 into the M1 monitors highlighted the off-menu items it won't do like my Nagra Jazz. Instead of maximizing the speaker's astonishing upper-octave informativeness, it added weight and punchiness. Visual qualities diminished, substance and weight increased. Playing the Rhythm 1.1 into my Swiss Wave 40 obviously did the same but translated different. With the Nagra's lither space recovery and upper-harmonic finesse, the soundkaos eggs felt better balanced. With the Backert they grew darker and thicker. All this navigates the systemic map. It steers and fixes the final balance where we want it. For review purposes it illuminates behaviour by way of triangulation into different ancillaries.

In terms of how hifi understands resolution, the term separation is perhaps most useful. The more sounds occur at the same time, the higher the likelihood that they compact, clump up and overlay. Hey, that's exactly what they do in a live venue particularly if you sit deeper within it to be surrounded by mostly reflected sound. At home and especially at lower volumes where the famous Fletcher Munson curve shelves off the frequency extremes, more separation equals more insight and intelligibility. To understand and follow intricate lines woven through dense musical textures and action, this core aspect of resolution—separating and thereby individuating coincident sounds into precise locations and instrumental or vocal sources—really helps. About that there can't be any discussion. It's not a question of being natural when playback itself is entirely unnatural (just two speakers with crossovers, the lot). It's a matter of effectiveness. It heightens the illusion which happens in our brains. We get to read the fine print as it were.

On that score my Nagra Jazz went further. Costing nearly twice as much, that seemed fair. Whilst upping volume will always make up for clouded-over visibility at low levels, with the Jazz and soundkaos speakers I could listen lower and see more. The thicker Rhythm 1.1 clumped together faster and even at higher levels never feathered or fanned out like the Jazz. That's usually the price to pay for increased heft and substance. In my hardware context and still with the Swiss speakers and Backert, the Job225 and Crayon as two very wide-bandwidth amplifier circuits, the first fully direct-coupled too, were the most copasetic to tread an ideal line between musicality and desirable hifi effects.

With the Mythology monitor and Jefferson Torno's Grand Cru Audio Horizon as two very accurate informative high-resolution speakers, I preferred Backert's contributions over Nagra's. They hung more meat on the well-defined bones without going overboard like lesser transformer-coupled valve amps can. Regardless of speaker, a consistent observation was unusual bass power on extension and amplitude. For that we tend to think power amps because those literally drive the speakers. Extrapolating, should one think of the Rhythm 1.1 as a superior amp driver? It did sound that way.

On the menu. To itemize my findings, Bob Backert's first ground-up preamp under his own brand builds its sound from the bottom up. Here it's the antithesis of bloat. This isn't an aged gone-to-seed heavyweight fighter à la Mickey Rourke's character. It's a young super-fit champ. The lower octaves are muscular, powerful, punchy and hard-hitting - more like transistors on the attack, more like tubes on round tone. In general this preamp is voiced for substance, weight, strong black content of the colour palette and rhythmically incisive behaviour. The latter isn't of the edgy speed-freak school. It simply adds decisive timing to the aforementioned mass. In terms of my two polarities, it's a musicality-first machine whose hifi traits come second. Resolution expressed as separation is high enough but not extreme like most modern hifi pursues it. Ditto for treble brilliance and associated edge limning. If it's those qualities you want, the Rhythm 1.1 isn't at the top of the charts.

If you've experimented with adjustable negative feedback on classic valve amps, you'll likely agree that higher feedback invariably dries out textures. In a subtle—or not—fashion it also tends to shift the rhythmic gestalt from swing to marching band. Something about musical flow gets choppier. Here Bob Backert's declared allergy to negative feedback and the complete audible absence of dryness and mechanical timing in his machine confirm such feedback experiments and the concomitant conclusions one draws from them. The Rhythm 1.1's tone is juicy, not desiccated. If you've thought of the 12AU7 as tonally and texturally less gifted than the 6SN7, Backert's use of it will come as a surprise.

That now hit all the high points. At 24.5dB, this deck champions high voltage gain. With the already promised revision to the TDK pot's taper to delay the onset of stout amplification factor, this no longer should cause issues of minimal range on the volume control before things get too loud. Functional conventions at this price tend to favour numerical volume displays but even my Nagra still relies on an old-fashioned motor-driven attenuator. Being a pure single-ended circuit, the Rhythm 1.1 lacks XLR i/o by design. Those would either be mere convenience items and as such faux XLR; or need quality summing and balancing transformers to increase parts cost. External build quality is ruggedly handsome without visible fasteners. Internal parts quality is high and the main circuit plus power supply sport a number of novel solutions. The tube access hatch is a clever wrinkle on a perennial problem, JJ ECC82 with silver pins and rubber dampers are stock. Well done team Backert Labs!
Packaging: Overbuilt and secure.
Fit'n'finish: Concomitant with price.
Features: Basic remote for volume but no mute or input switching, no XLR sockets, no display.
Tech: Novel power supply, novel impedance control circuit, high voltage gain, no feedback.
Pricing: Given competitors like ModWright, on the high side for featurization and trim.
Additional comments: Volume came on far too quickly in all my applications but the firm already committed to revisiting the taper on their motor-driven TDK attenuator.
Backert Labs website