Accuphase E-370 Stereo Integrated Amplifier
It’s eleven years since I reviewed the Accuphase E-213 for this magazine. That was then the entry-level integrated amplifier; the next model up the line, the E-308, was similar in rated power output but a noticeably more accomplished performer, and represented quite a significant jump in performance, back in the day. So I approached this review of the current equivalent, the E-370, with high hopes. A lot has changed since then, but some things have stayed the same: Accuphase’s styling, for one thing, and the E-370 retains the E-308’s nominal 100W output, albeit with better numbers into lower impedance loads. And the build quality and finish remain top drawer. But somewhat more significantly for me, they have managed on both occasions to produce the best, most musically satisfying amplifier to grace my system at the time.
And the other thing that hasn’t changed is that the raw power output figures don’t tell you very much; Accuphase’s performance seems to transcend mere earthly banalities like output into 8Ω loads, and such like. They should leave out the spec sheet and say ‘trust us, it’s fine…’. The technology is different now, too. Accuphase remains staunchly committed to the phase-accurate design principles that so captivated me when I heard the E-213. Still, more recent models also have a radical preamplifier design, and it seems likely that it is making a fundamental contribution to the quite remarkable performance of the E-370. Most of my time with the E-370 was spent listening via my Russell K Red 150 loudspeakers, but I was also fortunate enough to have the Fyne Audio F702s available still. Both of these speakers use simple, low order crossovers and pay attention to accurate phase relationships, so the Accuphase was very much at home, and the E-370/F702 is a particularly compelling combination, both sides seeming to play to the other’s strengths.
The amp also offers enormous flexibility and connectivity. There are five line-level inputs, plus two balanced inputs, and spaces for two optional input boards. One option is a configurable MM/MC phono stage, while the other is a DAC that offers co-axial, optical, and USB connections. You can have two of the same if you prefer, which could be ideal for those who use both MC and MM cartridges, or for those with two moving coils with different load characteristics. The pre- and power-amp sections can be separated, so you can take the preamp out to an external power amp, or bi-amp configuration, or use the power amp stage with an external preamp. Two hefty sets of speaker binding posts and the usual mains IEC complete a relatively comprehensive back panel.
The E-370 has that familiar Accuphase house sound: ever so slightly warm, slightly laid-back; confident without being assertive; powerful without being obvious. We start from a happy place, the E-370 and I. Elbow’s uplifting ‘One day like this’ from The Seldom Seen Kid [Fiction] is fresh, crisp, and tactile, with very well resolved string textures. Natural and relaxed, but full of dynamic expression, the sometimes choppy string accompaniment has a sense of impact and drive but doesn’t dominate the natural arc of the song. Guy Garvey’s phrasing drips with empathy too; it’s anthemic, as you’d expect, but it’s also just a beautiful song, imbued with even more meaning from the apparent sincerity of the performance.
Even non-jazz-lovers seem to connect with the Tord Gustavsen Trio (or maybe they’re just polite while keeping one eye on the exit) and ‘At Home’ from Being There [ECM] is one of my set-up tracks. I never tire of it but mostly because, in the right circumstances, it can be transcendent. It has a contemplative, luminous stillness, and if I get that, I know the system is working OK. Happily, it took very little time to get to that place with the E-370, but interestingly, I also went to places I’d not been before. In all that stillness, with the trio’s consummate delivery of textures, timbres, and timing, there’s also a real sense of a groove as the track builds and develops. Until now the recording has always been about mood, with a delightful but melancholic bent, so to discover a subtly subversive undercurrent of a groove, in a track that I thought I knew intimately, was slightly surprising. As was another track from the same album, ‘Wide Open’ which turns out to have some quite astonishing subtleties in the phrasing; the trio’s timing has gone from merely superb, to exquisite. I’m not a fan of hyperbole, but when the last track on an album leaves you sat in silence, savouring the musical experience you just had, ‘exquisite’ feels like an entirely appropriate term. It’s all in the tiny, micro-dynamic push, here, or the fleeting holding-back, there, or those fractional pauses, delays, or anticipations of the beat. And through the E-370 they so clearly and not only make sense but could hardly be anything else. If music can move you to tears, you’d better keep a box of tissues handy.
There are transparent amplifiers, and there are powerful amplifiers, and there are amplifiers that give you lots of detail. Still, I’ve not experienced an amplifier which delivers in quite the way that this Accuphase delivers. It’s not just about detail; it’s about the way the information is conveyed ‘just so’ allowing its contribution and relevance to the musical message to be understood immediately. If you boil it down to basics, it’s a combination of accurate micro-dynamics, pitch, and timing; though the reality the listener experiences is much more profound than that, albeit mostly at a subliminal level. You realise that all of a sudden, that album you used to listen to a couple of tracks from, is brilliant from start to finish. Or that you ‘get’ a band or a musician that you knew you ought to get, but somehow you’d never clicked with before.
A truly great artist can imbue a tiny gesture with more impact and significance than a lesser mortal might manage in an entire work, and that’s what makes them great. It’s a mastery of their craft, combined with intuitive artistry, and it’s the nearest thing I can think of to describe what it is that the Accuphase manages, and which few if any other amplifiers I’ve experienced can emulate.
Part of it, I’m sure, is the careful attention to the phase relationships within the music, which the company literally built its name on, but Accuphase’s proprietary AAVA preamp technology is doing something rather special here, too. Most analogue preamplifiers use a potentiometer, or a resistor ladder to attenuate the output received by the power amplifier stage. Accuphase argues that this varies the impedance within the amplifier, so that signal to noise ratio, and distortion figures, can vary depending on the volume level set. Their solution, dubbed Accuphase Analog Vari-gain Amplifier, is to take the input signal and feed it to a voltage-current converting amplifier. This solution consists of 16 discrete, parallel stages, each stage producing exactly half the output of the previous one. The preamplifier output sums these parallel outputs in different combinations, depending on the demands of the volume control. There are thus 216 possible output combinations or 65,536 volume ‘steps’, which is orders of magnitude more than even the best stepped-attenuator can manage. The volume control isn’t a potentiometer but instructs a control unit to select the necessary combination of outputs corresponding to the volume demanded, recombining in a current-voltage converter before being sent to the power amplifier stage.
The advantages of the AAVA implementation are said to be a virtual elimination of crosstalk and left-right tracking differences, and a significant reduction in noise, to the benefit of the signal to noise ratio. The frequency response is also more consistent, thanks to the invariant nature of the impedance seen by the signal. I suspect there’s also some benefit from not having an essentially parasitic component (the potentiometer, or resistor ladder) between preamp and power amp stage. Indeed, the Accuphase sound has a natural vitality and presence that speaks to the purity of the processing. It’s a bit like the difference between a passive and an active preamplifier. Passives tend to be transparent, delicate, and beautiful; actives tend to have more drive and energy, and in my experience, there does seem to be an advantage in having an actively driven power stage. In the case of the AAVA, you seem to get a good dollop of both; the delicacy, coupled with speed, drive, and energy of an active pre-. The circuitry is claimed to be electrically very simple, and hence reliable, and is also used to manage the balance control and attenuator (loudness) functions. (Accuphase remains committed to offering such fripperies as tone, balance, and loudness controls for all its amplifiers).
Perhaps the most obvious advantage is that music retains its energy and vitality, even at low listening levels. That ‘sweet spot’ where the volume level is just right for the music, is now mostly a thing of the past; pick a level that suits your mood. Accuphase provides a handy LED display which shows volume level as the amount of attenuation, in dB. My normal listening levels, depending on the recording, varied from about -27dB (positively antisocial) to -34dB (of course, no problem, officer. Thank you, sir). Abdullah Ibrahim, playing with the NDR Big Band on ‘Black and brown cherries’ from Ekapa Lodumo [Enja], retains its sense of scale and dynamics even at a setting of -42dB. In the process, the E-370 preserves the life and energy of the big band, and the image didn’t collapse down between the speakers as it usually does when played quietly. It kept all of its expansive exuberance and joyful enthusiasm; just did it more quietly.
So what we have here is an amplifier which uses considerable technical skill to interfere with the music signal as little as possible. Protection of phase relationships and almost obsessive preservation of fine detail pays enormous dividends when it comes to the rendering of the musical experience. Large-scale is more than adequately catered for: the LSO/Alwyn Tchaikovsky ‘Capriccio Italien’ [Decca] has some phenomenal dynamic swings and leans towards bombast in places, and there was no question the E-370 was up to the task at hand. My listening notes just read: ‘Bloody hell!’, which is shorthand for ‘a rollicking ride, which nevertheless preserved an excellent sense of the passing of thematic material around the orchestra – something often lost in translation’. It’s no one-trick pony, either. I’ve already praised the amp’s felicity with contemplative Scandy jazz, and now ‘When I am laid in earth’ from Purcell’s Dido and Aeneas [Apex] was almost unbearably poignant. The phrasing, the way the searing melodic line plays against the implacable ground bass, and the precise spatial placement of solo, choir, and orchestra, all contributed to a deeply affecting performance.
On to jollier things, and Pink Martini’s ‘No hay problema’ from Sympathique [Wrasse Records] was full of texture and tactile percussion, with a rich, full, but not overly lush piano tone. It’s quite a large ensemble, but their timing and phrasing are always immaculate, and the E-370 drew out every drop of its infectious charm. I have to confess to a certain amount of enthusiastic moving around, grooving, and pointing, to which fortunately there were no witnesses. The title track from the same album had real swing and sway, the skill being the way it manages to strut and stride along, while also being languid and louche. Sinatra, the undisputed genius of subtle timing, was spellbinding on ‘One for my baby’ from Only the lonely (Capitol) and Tom Waits’ ‘Take it with me’ from Mule Variations [Epitaph] had a sense of nostalgic intimacy that draws in the listener. These performers are all, in their way, masters of their art, and to appreciate their artistry, you need to experience all the subtle details and craft that sets them apart. But information without context is nothing, and in this case, ‘context’ means that facility of timing, phrasing, and precision that the Accuphase delivers without apparent effort. It takes genuinely outstanding technology to reproduce great art, and this is quite the best attempt I’ve experienced to date. It’s gone back to the distributors now. I am bereft.
Type: Solid-state two-channel integrated amplifier
Analogue inputs: 5× single-ended line-level only via RCA jacks; 3× balanced via BNC connectors; 1x power amp input (for an external preamp)
Optional mm/mc phono stage board
Digital inputs: Optional DAC board: co-axial, optical, USB inputs
Analogue outputs: 1× tape loop; 1x pre-amp output; 2× pairs multi-way loudspeaker binding posts
Input sensitivity: (line level input) 142mV for full output
Input impedance: 20kΩ
Signal to Noise Ratio: 107dB (at rated output)
Frequency response: +0 / -0.5dB 20Hz–20kHz
Bandwidth (@1W output): 3Hz–150kHz +0/-3.0dB
Distortion: THD 0.05%, 20Hz–20kHz, 4–16Ω load
Rated power into 8Ω: 100 Watts, both channels working
Rated power into in 4Ω: 150 Watts, both channels working
Damping Factor: 400 (8Ω load; 50Hz)
Gross Weight: 23kgs
Dimensions (HxWxD): 171 × 465 × 422mm