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Frederic Beudot
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Digital Source: Esoteric X-03SE
Analog Source: Acoustic Solid Classic Wood, AS WTB211, Grado Reference Sonata 1, Denon DL103, Clearaudio Nano, Ray Samuels F117 [in for review]
Pre-amplifier: Wyred4Sound STP SE
Amplifier: Genesis Reference 360, McIntosh MA2275, Yamamoto A08s, First Watt F5, JAS Bravo 3.1 [on loan]
Speakers: FJ OMs, Rogers LS 3/5a, Zu Essence
Cables: Zu Varial, Zu Libtec, Slinkylinks RCA, ASI Liveline interconnects & speaker cables [in for review]
Power Cords: Zu Mother, ASI Liveline power [in for review]
Powerline conditioning: Isotek Nova [on loan]
Sundry accessories: Isolpads under electronics, ASI resonators and sugar cubes, ASI HeartSong racks
Room size: 21' x 13’ x 7.5'
Review component retail: $2.399

Everybody in our hobby knows Nagra. Their phenomenal professional tape recorders are probably what brought them to everybody's attention decades ago - and more recently the more controversial pyramidal amplifiers. If you want to know the skinny on the company and their production facility, Srajan's RoadTour is certainly the place to start. What brought Nagra to my attention first were two other pieces of equipment though, their top-line PL-L preamplifier and VPS tube phono preamplifier. I am one of those who responds positively to their unusual aesthetics reminiscent of Nagra's tape recorders replete with laterally located connectors. But what really grabbed me about those two was how they sound.

There is a house sound to Nagra that’s stronger and more easily defined than that of most high-end brands. It is inherited from their rich analogue recording history, a sound first deep and rich yet also resolved, supple and dynamic. At least to my ears, Nagra has on occasion also lost sight of this grail and veered heavily towards the warm and rich to forget the supple and dynamic part of the equation. Up to now the two components which exemplified for me all the best qualities of the Nagra sound were the PL-L and VPS. I can now say with certainty that the BPS can be unequivocally added to this list.

Nagra's BPS is their tiny solid-state battery-powered phono stage - with two twists. The first is that when I say battery, I mean a single disposable 9V battery. Without charger or wall connection, the BPS sits on a shelf completely isolated from the rest of the world except for the turntable input and preamp output. I am in general ambivalent about battery power for musical reproduction, especially in amplifiers where perhaps I have not yet heard the right ones. When it comes to phonostages and their micro-volt signal however, there’s simply nothing better for ultra-quiet operation and extreme resolution.

The second twist Nagra implemented in their tiny enclosure—4.25" x 9.06" x 6.25" or 27 x 160 x 110mm and 16.9 oz or 480 grams—are their proprietary MC step-up transformers otherwise found in their far pricier top-line products. According to Nagra, the entire BPS circuit is actually lifted from the bigger VPS, simply omitting valves to run a solid-state final gain stage instead. This thriftier solution allowed battery power which reduced enclosure size to barely more than two stacked CD cases although weight is far more substantial than two CD cases. When you buy Nagra, even with their entry-level phono preamplifier there is no compromise on vaunted build quality.

The review sample was from the initial production run and only offered fixed 64dB gain but future production will offer jumper-set 54dB and 64dB. This gives greater headroom in systems with enough gain throughout to not need the full 64dB from the source.

Lifting the hood allows loading changes, with various options provided on small circuit boards to be screwed right behind the input connectors. Initially Nagra provided boards with a variety of resistance and impedance combinations but quickly realized that users did not really want the various impedance options. Current production provides only 100pf impedance but more resistive loading values (100, 150, 220, 330, 470, 1,000 and 47,000 ohms). This is a smart move. I have yet to hear the effect of MC impedance loading but can clearly hear the effect of fine-tuning resistance, especially with step-up transformers which seem to me even more sensitive to it than transistor gain stages.

If you've read previous installments in my series of phono stage reviews, you know that I am not too kind to manufacturers of pricey phono stages which don't grant access to those settings on the fascia. It's all done in the name of sound quality as though that required taking a preamp apart to fiddle with minuscule dip switches or jumpers. As aptly proven by Esoteric and others, it’s well possible to make a phono preamplifier that is far more convenient and sounds great.

Yet here I am about to cut the Nagra BPS a little slack. Yes, one has to dive inside to change loading boards but considering the size of the enclosure, the fact that it holds two step-up transformers and at what price it is offered, this concession may actually have been necessary – even though the next in line Ray Samuels F117 phono preamplifier is even smaller yet offers double-mono gain and loading controls with rotary front-panel knobs (but no step-up transformers).

While still inside the Nagra, you can you move three of those dreaded jumpers between MM, MC single-ended and MC balanced operation. Nagra recommends single-ended MC unless you have noise or hum. I went single-ended as recommended and operation was so silent that I forgot all about this option until I checked the manual again to write this review. It's nice to know it’s there but I didn’t need it.