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Nagra PL-L Preamp and PMA Mono Amps Reviewed

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Performance
4 Stars
Value
3 Stars
Overall
3.5 Stars

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Very few brands, regardless of product type, earn 100-point ratings. Even Leica and Rolex have fouled up at least once in the past, however unlikely that seems.* Nagra is the closest audio has come to producing a brand with an absolutely blemish-free record. I've said more than once that, if I had to get rid of everything in my listening room and choose one system for the rest of my life, it would include a Nagra PL-P and a pair of VPA valve monoblocks.

Additional Resources
• Read high end monoblock amp reviews from the likes of Krell, Mark Levinson, Audio Research, Classe and many others.
• Read unique audiophile preamp from Benchmark Media, Copland, Gryphon and many other companies reviewed here.
• Learn more about Nagra on this resource page.

So it was with glee and even intumescence that I received news that I would be reviewing a Nagra pre/power combination. The pre-amp would be the PL-L line stage, while the amplifier would be a pair of the new PMA Pyramids, which had been seen at a couple of shows and left observers scratching their heads. Unlike every single product Nagra has produced in its 50-plus years, this is the first that seemed flippant, an aberration that has nothing whatsoever to do with the brand responsible for the world's finest tape recorders, let alone a range of high-end audio gear that's good enough for David A. Wilson to take to hi-fi shows for his demonstrations.

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I say that because you must appreciate the seriousness of Nagra. This is no gathering of borderline-psychotic Eurotrash audiophiles out to prove points amongst their peers. Although the chief designer is - how do I put this? - not a little eccentric, Nagra is, first and foremost, Swiss. And frivolity is not part of the nation's character. They even have quiet orgasms. Be that as it may, I was prepared to take the PMA seriously because of the badge it bears. But a little voice in the back of my head kept whispering that someone at Cheseaux believes in 'pyramid power' and its metaphysical connotations. Spooky...

PL-L Pre-amplifier
Following the familiar PL-P phono-equipped valve pre-amp on which it's based in part, the PL-L is a line-level-only version with one added fillip: remote control. The two pre-amps use the same case and look very similar bar one or two changes in facilities and knobbery, but they can confuse some users by asking of them: which to buy?

If you're either extremely wealthy or a Nagra obsessive, you'd buy both, for they are complementary, and most certainly mutually exclusive. In which case, you can look at it like this: the PL-L, at £4950, is either an expensive way to add remote volume control and four more line inputs (one balanced XLR and three unbalanced) to the PL-P, or the PL-P is a costly way to add a phono stage to a PL-L. Considering the number of people I know with both, it begs the question: why doesn't Nagra do an all-tube pre-amp with remote control and phono? Or is that too simple?

One other crucial concern when making your decision: the PL-P runs off of a rechargeable battery system while the PL-L is mains-driven via an outboard power supply. Now, pay close attention, because here's where a subtle audiophilic cause celebre enters the picture. We all know companies that rave about the superiority of battery drive, and with much justification, e.g. LFD. Thus, there are listeners who insist that the PL-P sounds better on line sources than the PL-L, marginally warmer and richer, with better dynamics and certainly a lower noise floor. But believe me: both products are world-class, and you'd be more likely to choose one over the other because you prefer phono over remote or vice versa, rather than for relative sonic merit.

Which ever you choose, the bottom line is that you'd own a sublime, all-valve Nagra pre-amp in the same anodised, machined-from-solid aluminium block, fabulous controls, side-positioning for inputs and outputs, joyous ease of use despite the wealth of features, and sound that, well, let's get to that in a moment. Niceties include user-adjustable internal settings for gain matching and for setting up the way the PL-L deals with other components relative to the remote, there's a valve-life timer and other under-the-bonnet facilities. And you will, at some point, take the lid off for accessing some feature that makes the PL-L seem more like it was personally tailored to your set-up.

While inside the PL-L, you'll notice superb workmanship, three valves (two ECC83s and one ECC81, hand-selected and burned in for 12 hours before testing), assorted banks of jumpers for level-matching and remote control suitability, a brace of Nagra-made balanced toroidal output transformers and the massive ALPS-made level and source controllers. But for many of us, the seduction comes in the form of one thing above all others, the legendary round metering system called the modulometer. This multi-purpose analogue meter indicates relative dB levels, controlling the power supply DC input level, power supply behaviour, compensating for level differences between various recordings, output level of the amp, establishing precise balance between left and right channels and more. As one observer noted, a Nagra product without a modulometer somehow isn't right.

The PMA Pyramid, it should be noted, does not bear a modulometer.

Unlike the PL-P, which has a left/right input level controls, the PL-L establishes balance with a conventional balance rotary. The volume control, too, operates like a normal rotary, but the source selector has a separate position in addition to inputs A-D to which you turn if you're using the remote; A is the balanced input. Other controls include a mono/stereo toggle switch, a toggle for changing the functions of the modulometer and a third for choosing between Outputs 1, 2 or Mute. Everything about the PL-L reeks of professional usage, from the wholly functional styling to the feel of every control. Despite tidy dimensions of only 12.2x10x3in (WDH), it oozes gravitas.

Given its background in studio work and on-location recording, Nagra has a mind-set that separates it from audio convention. The outputs are a perfect example. They're directly coupled to the output vacuum tubes, to ensure the highest audio performance, and the level of the output connectors can be modified to match the specific level of the amplifier; the PL-L can drive loads as low as 600Ω. The aforementioned front panel toggle selects either Output 1, which addresses two unbalanced sets of RCA stereo connectors, ideal for, say, bi-amped setups or to connect to both amplifiers and a recorder, or Output 2, which terminates in unbalanced XLR connectors. One option is custom-designed Nagra-made transformers for floating output.

Despite this, the PL-L is just as apt for domestic users, including couch potatoes. The machined-from-solid remote control allows source selection and adjustment of balance and output level via motorised pots. As Nagra notes, 'This means the remote control does not degrade the sound quality; the audio signal path remains unchanged.' The PL-L's remote can also control the Nagra DAC and the MPA-RCMI amplifier.


PMA Pyramid Monoblock Amplifier
Heralding a 'new family of solid- state amplifiers based on a unique pyramidal design' is the £6995 PMA Pyramid Monoblock Amplifier, which will be followed quickly by the PSA Pyramid Stereo Amplifier offering 100W/ch for £4250. Each PMA delivers 200W into 8Ω, and one thing you can't deny it is recognition for it sheer muscle. But here's where I start smelling the whiff of patchouli: 'The revolutionary concept encompasses an aluminium pyramidal design that is as functional as it is distinctive.' Sorry, guys, but an 11.8in tall pyramid with a 14.9x14.9in footprint is functional, especially when its heat sinks will lacerate fingers, when most equipment shelves aren't that deep, when they can't be stacked, ad nauseum.

Why not just come out and say that you want to be noticed?

For a company that prides itself on being technical, Nagra has chosen instead to be coy about the PMA. Sure, there's lots about the Power Factor Corrector, a device 'that acts like a reserve of power to deliver pure DC voltages to the amplifier.' Which is kinda like saying you don't need to buy an outboard mains stabiliser/filter for this. And who needs to be told the basics of monoblock superiority over stereo amps with shared power supplies? 'The monoblocks architecture allows each channel to have its own powering unit. This improves the channel crosstalk and also the response to transient signals, in other words: natural and musical rendition. In addition the amplifier can now stand close to your loudspeaker allowing you to shorten speaker's cable length and thus increasing the quality of your system.' Hey, fellas, we know all this.

My colleague Paul Miller (see p ?) will delve into the technicalities. Suffice it to say that even with my non-technical background, I am suspicious of 200W amps that weigh only 10kg and seem to contain very few components. Even a dolt such as I knows about digital switching amps and switch-mode power supplies and other CE-blessed ca-ca.

I should state here that the review sample is an early edition, probably pre-production. Which might explain the mechanical buzzing. Even so, the flimsy pyramid section certainly doesn't suggest manufacture by Nagra, while the poorly finished casting that makes up the base must have been modelled on those at Cheops: rough around the edges.

You do, however, get a hint of Nagra is in the back section, where you find both balanced and unbalanced inputs on XLR and RCA connectors, decent binding posts, the on/off rocker switch and jumpers for balanced or single-ended operation. You can calibrate the level for maximum power internally for 1 or 2V to allow the pyramids to be compatible with any preamplifier or DAC. Although not functioning on the early sample, the PMA features auto-detect power-on, so it will start automatically when receiving a signal on the input connectors. It will also turn off after 20 minutes if it doesn't receive a signal. Other specifications include 10Hz-70kHz frequency response, 104dB signal to noise ratio, and THD of less than 0.09% at 200W.

The PL-L and PMAs were used in a system with SME Series V Arm, Transfiguration Temper V Cartridge, SME 30/2 turntable and Audio Research PH5 phono stage at one end, and Wilson WATT Puppy System 7 at the other. Also used were PMC DB1+ monitors for their sheer hunger, and Musical Fidelity X-RAYV3 and Marantz CD-12/DA-12 CD players. For the sake of comparison, other pre-amps included the McIntosh C2200 and Musical Fidelity X-PRE3, while other amplifiers were the McIntosh MC2102 and Musical Fidelity X-200. I played mix'n'match, using balanced and singled-ended connections; wires were either Transparent Ultra or Kimber.

Because the PL-L arrived first, I was able to insert it into both the Musical Fidelity and McIntosh systems for solo assessment. I wasn't disappointed. A friend who'd just purchased a PL-P confirmed that the differences between the two were negligible, but centred around the PL-P's 'warmth' and unbelievably suppressed noise floor, but he said he'd be happy with either.

What a pre-amp! Absolutely vast soundstage, which carved out a huge playground for big band sessions from mono Billy May on Capitol LPs to some Mel Torme, Bobby Darin and Dino sessions on CD. The PL-L's neutrality, with only the merest whiff of valve-y cuddling, bettered every pre-amp in my arsenal. The C2200 offered slightly faster attack and smoother decay, but the PL-L never sounded like it was struggling to resolve the natural behaviour of the start and stop of the notes. Voices were natural, with a 'BBC feel' to them that was inescapable: you could imagine this pre-amp in a broadcast studio.

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