NVA

INT400 Integrated Amplifier

£3,500

The rebirth of Nene Valley Audio continues. If the story of this small independent British hi-fi manufacturer has hitherto passed you by, then let me briefly recap. The company was started forty-one years ago by Richard Dunn, formerly of Tresham Audio. It's fair to say he was a square peg in the round hole of hi-fi back then – and indeed for most of his life until his recent passing.

He made ultra-minimalist amplifiers that were carefully voiced to sound natural, smooth and beguiling – imagine the opposite of a mid-nineteen eighties Technics integrated, and you're getting close. The magic dust that he sprinkled on his products built him a small but dedicated following – and full disclosure here, I was one of them. I bought a brand new NVA AP30 integrated in 1987 after hearing it against all its market rivals in the dem room of an excellent dealer nearby.

Richard's maxim was, “If you can do without it, then do without it” – and so he did. NVA amplifiers were not and are not blessed (or cursed) with extensive protection circuitry and other such things. But that's not to say he had a slipshod approach, as he paid great attention to signal paths, circuit boards, grounding, wiring and so on. Indeed, you could almost say he was ahead of his time in this respect. The result was a range of compact, low-power solid-state amplifiers possessing an unusually charming sound.

As many fans of the brand know, NVA is now owned by Hi-fi Subjectivist Audio Ltd. – and run by ex-NVA employee Tomasz Danus and Hi-Fi Subjectivist forum member Paul Tiernan. The guys have been slowly rationalising the old range, improving the component and build quality of the products and streamlining the designs. Paul's avowed intention is “not to change the electronics, just implement them better”, he tells me.

The INT400 sits slap-bang in the middle of NVA's new three-strong integrated range, with the INT250 costing roughly a third less and the INT400SA a quarter or so more. All three are direct descendants of the aforementioned AP range that date back to the early eighties. So, for yours truly, spending time with the new INT400 is – in the immortal words of George W Bush Junior, “like deja vu all over again”. This is literally a better-made and modernised AP70 – but the basic design has been frozen in time. In this respect, in car terms, it's kind of like buying a brand new mid-eighties Porsche 911 in 2023 – a purposeful minimalist product that hasn't yet been weighed down by all the complications of modernity!

UP CLOSE

The pure eighties minimalism of the INT400 means that it doesn't have so much as a balance control. It comes in a neat, compact, satin-matt black acrylic case with disappointingly cheap plastic volume and source selection knobs. Paul Tiernan tells me that the company may be offering better quality items and/or optional metal types in the future. Yet I rather like the existing ones, as they're a testament to the fact that the money has been spent inside the product, rather than outside it. Indeed, this amp is rather cool in a 'less is more' kind of way. When I bought my AP30 in the eighties, it was one of the most minimalist products even then – so, with no power meters, displays, streaming modules, DACs, etc., this new model looks even more hardcore now.

Like the rest of the amplifier, the circuit boards are made in the UK using the latest selective soldering technology, according to NVA. The electronic components have been uprated for superior sound and reliability compared to the old generation. Indeed, he claims that the company's amps have never been built to such high standards as they are now. The amplifier's preamp section is passive, and there's a choice of volume potentiometers. In the entry-level INT250, you get a good, basic ALPS type, and on this INT400 model, there's a premium TKD fitted. The range-topping INT400SA gets, as its initials suggest, a 34-step Seiden switch with Audio Note load resistors.

Everything from the PCB material and tracks to the internal wiring and grounding has been improved. High-quality Vishay capacitors are fitted – although fewer of them than expected are present to keep the signal path as short as possible. Silver-coated stranded copper wire with a Teflon dielectric runs from the input selector to the board. The power supply has been upgraded, with up to 400VA now on tap, and Toroidy audio-grade transformers are used in this model; the top INT400SA gets two of these mains transformers, by the way.

The amplifier sports six line level inputs, all unbalanced RCA – sorry, no Bluetooth or Ethernet here! There's a choice of either tape or preamp outputs (the buyer specifies which), and the claimed power output is 70W RMS per channel into 8 ohms. This should be enough for most people, especially with more efficient modern speakers. I found that this amp worked well with most types that I had to hand, but I certainly preferred easier loads and/or more sensitive speakers – it simply isn't a muscle amp and shouldn't be treated as such.

The usual caveats apply to NVA amplifiers. If you plug your speaker leads into your speakers when the amp is switched off, meaning you cannot accidentally short the leads with one another, then this product should be as reliable as pretty much anything else around. However, if you don't use your common sense, then it may go wrong as – in Richard Dunn's famous words – “it's not unconditionally stable”. It also works best with NVA's own loudspeaker cable. “We recommended owners to use NVA LS2 budget loudspeaker cable or the more high-end LS3 type”, says Paul. I can certainly vouch for the fact that my old AP30 sounded far better with NVA speaker leads. The company offers a five-year first-user warranty.

THE LISTENING

Perhaps I'm biased – as I did once pay for an NVA amplifier with my own money – but the INT400 is, I think, a fabulous performer. For me personally, it absolutely hits the spot because it offers a great combination of delicacy and insight – it's a relaxed, high-performance product, you might say. This isn't a headbanger of an amplifier, then, yet it's actually surprisingly enjoyable playing some pretty raucous and edgy music. That is, to my reckoning, down to the sheer directness of this design; it seems to be able to go into any recording, ferret out the important things about it and reproduce them in a clear and effortless way. It doesn't sound super-analytical, yet it's still really detailed.

By way of example, take My Bloody Valentine's When You Sleep. If you're into indie rock, this is one of the finest genre-defining tracks, in my view. It's a wonderfully melodic, dreamy song, yet all this is hidden under a wall of dissonant noise. It's as if The Byrds or The Beach Boys had reinvented themselves as grunge bands in the early nineties, you might say. The production is also extremely compressed, too. Few hi-fi amplifiers can really do it justice, as it's just too painful for many and requires a combination of very low distortion and great grip from an amplifier. Yet the INT400 breezed through it as if it was playing a Carpenters record. My mind was taken away from all the screeching and graunching noises so I could focus on the lovely, lazy vocal line with its wonderfully romantic lyrics. The NVA amp just lapped it up, even pushing fairly high volumes – something that very few rivals around its price can do.

This amplifier has a delightfully smooth tonality but doesn't achieve this by simply adding warmth or obfuscating the grisly detail. Rather, it simply cuts to the musical chase – the core of the recording – and renders it in an emotionally engaging way. It's as if all the conventional considerations of fine detail, stage depth, etc., seem to go out of the window, and the listener instead gets sucked into the drama of the occasion. All the same, the INT400 can be a broad-shouldered amp when it needs to be, as Yellow Magic Orchestra's Nice Age showed. This huge, thumping technopop track features a young version of the (sadly recently deceased) Ryuichi Sakamoto. It contains fat electronic bass, chugging rhythms and crashing, sweeping choruses – all of which the NVA proved highly adept at communicating. Okay, so it doesn't have wall-wobbling low bass power, yet it carried the bassline in a wonderfully fluid way. The vocals were surprisingly pure sounding, too, even on the song's epic crescendos.

The NVA's soundstaging is very good, especially with programme material that really depends on its sense of atmosphere and space. The INT400's rendition of Beethoven's Pastoral Symphony with Karajan and the Berlin Philharmonic was quite sublime. It doesn't give you the sort of detail you'd expect from, say, a high-end pre/power amplifier combo, but it is still surprisingly spacious. There's a sense of depth and dimensionality that, to my ears, betters rivals such as the (already very good) Exposure 3510 integrated – although to be fair, the latter makes up for it in other ways, such as its super muscular sound and deep, plummy bass. The NVA is more a delicate flower, you might say. It doesn't quite seize the recorded acoustic and throw it at your loudspeakers but instead places it out there for you to hear should you so wish. And if you do, there's an awful lot going on from the front of the concert hall to the back.

Yet what really makes this couth, civilised-sounding device so special is its innate musicality. It's 'cliche alert' time, I'm afraid, readers, as I am forced to mention tube amplifiers at this point. The way that Beethoven's 6th just wafted along in my room with such consummate ease yet so much emotion rather reminded me of a good EL34-based valve amp. The INT400 is one of those amplifiers that can take recordings which sound awkward and rambling through other amps and turn them into magically involving musical moments.

Roxy Music's Avalon is a case in point – it's a great song in my view but can sound tired and unexciting through some hi-fi systems. In reality, though, played on the right kit, it's ethereal, dreamy and romantic in a way that really touches the soul. This classic early eighties pop/rock number is extremely well recorded and very subtle, too – but you have to be in the mood and with the right replay system to get its true power and passion. The NVA was brilliant here; all the different strands of the mix syncopated beautifully to give an entrancing groove. At the same time, Bryan Ferry's famous 'coffee cream' voice hovered over the instrumentalists as if he was on some sort of gilded throne above. The sheer evocation of mood that the INT400 is capable of is quite a thing for a product of this price and also a testament to the brilliance of its original designer.

Overall then, it is hard to fault the INT400 on its own terms; it's not built to usurp 250W Krell monoblocs, nor is it a natural alternative to the latest Technics digital amp. But when put against its closer rivals from Cyrus, Exposure, Naim and Rega, for example, it has an awful lot to offer sonically – not least because it doesn't sound like any of them in particular, and thus gives buyers in the segment even more choice. It's great across all types of music, with the caveat that it's not going to make any of them sound like you're right in front of the PA at a Megadeath concert. It has all the passion of the best integrateds near its price, yet it seems to bring more subtlety and charm. As such, the NVA is well worth investigating – it may be just what you're looking for, especially if you haven't found it so far…

THE VERDICT

NVA's INT400 is that most unusual of things – a highly distinctive product from a crazily charismatic decade (i.e. the eighties) that has been brought into the twenty-first century. And now here, it seems even weirder than it was the first time around! Yet I don't mean this in a bad way; quite the reverse. Other amplifiers are available, as they say if you want an iron-clad 150W of power with the music stencilled onto your forehead. But if you want to be beguiled by some seriously interesting audiophile exotica, this could be for you.

Visit NVA for more information