A complete NVA amplifier system…
P50SA MKII preamplifier, S150 power amplifier, M300 monoblock power amplifiers

A HiFi WigWam review by Richard Bowles


All together now…
NVA is something of a ‘boutique’ brand, known for its founder’s somewhat eccentric approach to design. A comment that can equally be made about its marketing, or lack thereof. Nevertheless, NVA has undergone some changes of late, and though the characterful nature remains, the product range has expanded substantially. The opportunity to review a number of the company’s amplifiers, and it’s top of the range passive preamplifier, was too good to miss. Hence, the arrival here of a P50SA MKII preamplifier, S150 power amplifier, two M300 mono power amplifiers and an assortment of interconnects and speaker cables. The aim was to run a complete amplifier setup, with the S150 for treble and the M300s for mid/bass. The majority of the review is with that configuration, although I did swap around a little and there is also a part about the preamplifier, as this will doubtless be considered as a standalone purchase by some. As a result, I make no apologies for the review being somewhat extended.

NVA are rare, if not unique in their approach to system building. For a start, their warranty is voided if anything other than NVA speaker cables are used, and their power amplifiers are specifically intended to be used only with one of the NVA preamplifiers. By way of an introduction, it’s probably worth quoting direct from the company itself: ‘we are interested in the best sound quality at the best price. We make no allowance for the user beyond what is critical to the operation of the equipment’. What this means is that you can forget remote controls, experimenting with different cables and suchlike. In the past, that meant limited options, but NVA now has choice of four phono stages (two moving magnet and two moving coil), two (passive) preamplifiers, three stereo power amplifiers, two monos and a few headphone amplifiers, giving far greater variety and more upgrade opportunities. There are also a number of different speaker cables and interconnects.

The main products are now split into the ‘Model Worker’ and ‘Artisan’ ranges, but the aesthetics remain similar and are based on the original ethos of using non-metallic cases, built from an acrylic compound (with the obvious exception of the top-mounted power amp heatsinks). The look is minimalist, clean and attractive. Long-term use will need some care though, as the casework will be easy to mark. The idea of removing the electrical properties of a metal case is not new, but does demand some care in terms of placement. A little initial moving around proved necessary, but not difficult, and once sorted, the noise floor here was more than acceptably low.

First impressions
On the rack(s), the NVA casework looks neat and impressive, and in their time here, the equipment attracted positive comments from various visitors, both in terms of looks and of sound. All the cases are relatively compact and will fit easily into normal racks, though the comments about location have to be borne in mind, as does the need for some space above the power amplifiers. That said, even with some (very) enthusiastic volume levels, they barely even got warm to the touch here. The P50SA in its latest spec has a useful four inputs, plus tape, and an unusual and welcome three sets of outputs.

Let’s start
The amplifiers arrived with the comment that they had been ‘round a few dealers’, so already had a reasonable amount of running time. Out of respect (and experience), I nevertheless let them have a few hours of CD on repeat once plumbed in. Then, on with some initial listening. I used my standard sources for most listening, as I am familiar with the ‘sound’. Most auditioning was with Living Voice speakers, though I did a little back breaking to also try some B&Ws and aiming for variety, a pair of KEF LS50s.

First impressions count, and that first impression is ‘musicality’. Bearing in mind that my yardstick is large single-ended triode valves, this is slightly unexpected. I anticipated sonic weight and clarity. There is no lack of those, for sure, but not in an evidently ‘solid state’ way. Right from the first listen, there is a sense of reality: performers and instruments are located properly in space. A really good tonal palette as well. So, on with some listening with music I know reasonably well. First up, Jean-Michel Jarre, Concerts in China on vinyl. This is a very decent recording for a live concert and the surprises start coming. A really large, 3D soundstage extending well past the speakers, excellent control and rendition of the mids and a light and open-sounding touch with the treble. As expected, bass rendition is good as well. Not overly emphasised or obvious, just tight, clean and deep, with real speed and slam where it’s on the recording. Interesting. Another favourite here: Eric Clapton with JJ Cale, Live in San Diego, streaming this time. This is another well-produced album with a very atmospheric feel, which the NVAs keep beautifully intact. Vocals in particular have real presence, but the transients of the snare drum are also edge of the seat real. It gets played twice; once for review purposes, and then again for the sheer pleasure of listening. This is good.

Moving to some studio recordings and we can see whether this ‘solid state that doesn’t sound solid state’ passes the good old hifi test of boring female vocals. Except that I prefer non-boring female vocals, so rifling through the CD shelves, Imogen Heap, Ellipse has to provide the answer. Which comes in the form of a big ‘yes’. This is a voice and a recording that can easily tip over into harshness and become unpleasant to listen to, but it doesn’t. The ‘edginess’ is there, exactly as it should be, but it’s perfectly portrayed and never gets too much. Along similar lines, Leonard Cohen, Ten New Songs. My CD of this is a slightly ‘hot’ recording and another one that can very easily sound a touch glaring, but not here. The raw emotion is there and Cohen’s voice comes across centre stage in all its gritty reality.

This is proving interesting. I can think of a few amplifiers that have spent a bit of time in the listening room here and have pulled off the trick of ‘not sounding anything’, but not many. By that, I mean they don’t sound like valve, solid state, class A, class D, etc. What goes in is what comes out, but with some subtle ‘something’ added. In particular, the soundstage and the feeling of airiness, but combined with serious clout. It’s hard to explain without resorting to dreadful clichés, but it’s extremely enjoyable to experience. It usually also comes accompanied by the sort of costs that are painful. On this basis alone, the NVA setup is playing seriously beyond its price point.

Time for a harder test, by moving on to some things that are big hitters in terms of dynamics. Both ends of the musical spectrum here, first, Toots and the Maytals, Got To Be Tough. The title track could sum up the album, as reggae needs more than just power to sound like it should. And it does (sound like it should). Great bass and drum attack. It’s fun, and it seems more like a window into the recording than just a replay of it. The other end of the musical spectrum? The Verdi Requiem. The Decca Solti recording with Sutherland and Pavarotti. My usual all-valve system struggles a touch with this one at higher listening levels, as the dynamics are massive. But not too much for the NVAs, which have enough in reserve. Most ‘powerhouse’ equipment handles the dynamics of the Requiem with ease, but in the process somehow sucks the life out of it. This time, it’s different. Not just because of the dynamics and the sheer energy, but especially because the vocals are presented superbly. It’s almost as if there are different amplifiers working in perfect harmony to cover all the bases. It’s not a unique trick, but it’s not common either. And it’s highly enjoyable.

Before some loose conclusions, a few words about the cables and the preamplifier. For the former, I did some swapping around and used the NVA cables in my normal setup. They proved to be open sounding, with no apparent (unwanted) effect on any part of the frequency range. Between my SUT and phono stage, they were also pleasantly quiet. They appear to be designed and constructed decently, with no ‘fairy dust’ and exotic materials, just sound electrical practice.

I also ran my normal system with the NVA P50SA passive preamplifier for a while. This is really a rather unfair ‘test’, as the setup here is designed around an active valve preamplifier in terms of gain and ideal matching with the power amp. Nevertheless, the P50 acquitted itself extremely well. Again, nothing added, nothing taken away. It’s worth noting that this is a stepped attenuator design, and some serious attention has been paid to component choices. Seiden rotary switches and Audio Note resistors would not be out of place in very high-end equipment, and do not come at bargain basement prices. Moreover, obvious care has been taken over choosing resistor values. My normal issue with stepped attenuators is a lack of fine adjustment at low volumes. In my system, as well as with any combination of the NVA power amplifiers, I had no such issues. For once, the volume I wanted always seemed to be available. I did not have any problems with noise pickup here either, despite the non-metallic case. There was some slight hum evident when touching the controls, but that would not be any issue in normal use, of course. Overall, it’s impressive for the fact that it does not try to impress with any sonic ‘tricks’, but simply works as it should.

So, where does that leave us? Frankly, with some equipment that turned out to not be what I had expected, but in a very good way. I anticipated that with three power amplifiers and relatively efficient speakers, decent volume levels would hardly be a problem. I also expected good dynamics and decent bass. There is all of that, and more besides. Bass is nevertheless not overpowering or flabby. It’s tight, well controlled and with very good definition. The real surprises are the treble, and especially the mids. Seriously good portrayal of vocals is a trick that a lot of equipment can’t quite manage, but the NVAs seem to. It’s that ‘in the room’ feeling that really has the ability to grab your attention, but without sounding sharp, or hard to listen to. Add that to a beautifully clean and open top end, and what you have is something that makes listening a real pleasure, not only to just dip into, but equally for seriously extended listening sessions. The latter has been evidenced by the dark circles under my eyes on more than a few mornings while the amplifiers were here. The sign of a really good listening system is when you put one LP on late at night and end up going to bed at silly-o-clock. The NVAs do that to you.

The tech stuff
I’ve kept this very basic in view of the length of the review. More info is on the manufacturer’s website.

P50SA MkII preamplifier:
23-step attenuator passive
Four line-level plus direct inputs
Three pairs of outputs, plus tape out.

S150 stereo power amplifier:
60 watts per channel power output

M300 mono power amplifier:
70 watts power output

Manufacturer’s website


Concluding thoughts
Many people talk about a ‘valve’ sound or a ‘solid state’ sound, because both have their advocates and both have their benefits. That doesn’t have to mean pleasant distortion or added emphasis, simply that some of the best valve amplifiers have a magic touch with vocals and some of the best solid state manage the same with bass, dynamics and transients. The NVA amplifiers seem to offer the best of both worlds. The vocals and the airiness of the treble are a surprise, while the bass and dynamics are as good as expected. There are few downsides that I can find. Care is needed with positioning and layout in order to avoid interference pickup, though that would be considered good practice anyway. The gloss black acrylic would be very helpful in a crime scene, as its ability to collect and display fingerprints is possibly unmatched, and every speck of dust also stands out. A lot of care in use will also be needed to avoid scratches and marks. On the other hand, there is no denying its understated attractiveness.

The NVA approach has always been based on few compromises: the lack of protection circuitry (and therefore the requirement to use only NVA speaker cables), acrylic cases, captive mains leads, etc. The principles are also firm: keep circuitry as simple as realistically possible, but use high-quality components and power supplies. Some of this is definitely outside of standard hifi enthusiast territory. Some will certainly dislike the lack of options to experiment with cables and will bemoan the lack of a remote control. Others will delight in having such temptations taken away. NVA not only accepts its ‘Marmite’ appeal, but embraces it, going so far as to use an image of a jar in its marketing.

I am not a great fan of spreadable yeast extract. However, I am a great fan of music and of finding the best ways to listen to it. I must therefore to be counted on the list of people who are also now fans of NVA. Even as someone who gains enormous pleasure from ‘tinkering with audio stuff’ I can see the appeal of a plug-n-play type of solution, but regardless of that, the sheer musical enjoyment is something I cannot ignore. Coupled with what seems very reasonable pricing in view of the sonic ability, there seems no reason not to give the NVA amplifiers a very firm recommendation.

Musical enjoyment
Excellent handling of vocals
Clean, tight and well-defined bass
Extended and open sound

Easily marked casework
Care needed with positioning
Lack of facilities
No remote
Restricted to manufacturers cables