⌈ ACCUPHASE presented its first stereo amplifier over half a century ago, in 1973. Since then, the Japanese brand has become one of the most recognized and respected in the world. The company has earned its reputation by offering high-end amplifiers (including class A), preamplifiers, and CD and SACD players. We are testing the AB Class E-4000 integrated amplifier. ⌋

WHEN LOOKING AT THE range of amplifiers offered by Accuphase, a manufacturer based in Aoba-ku, a district of Yokohama that is home to Kodomo no Kuni, a park famous for its pony rides and petting zoo, we see that the amplifier we are testing is currently the most affordable (read: cheapest) amplifier from this company's new range. Although there are two more devices of this type below in the price list, the E-380 and E-280 models, it is immediately apparent that they belong to the previous generation, still described by three-digit symbols. And they are no longer offered.

Until this changes, the E-4000 is the first step for those who would like to see what this well-known audio company has to offer. And there is a lot to look at. The tested device is a large, weighing 25 kg and measuring 465×181×428 mm integrated amplifier operating in class AB, offering high output power (180W / 8Ω, 260W / 4Ω), high damping factor (800), and extremely extensive functionality, with a multitude of analog inputs and outputs, both balanced and unbalanced, as well as optional cards - a digital-to-analog converter and phono preamplifier.

Its special features, in addition to the extraordinary precision of workmanship and engineering attention to measurable parameters, are the gold color of the front panel and the characteristic VA meters. Gold is a pleasant change from the black or silver devices that have dominated our industry, and it is still on “the” side of the line that separates good design from kitsch. As a result, the devices have a cheerful appearance. Maybe that's because the district where this manufacturer is based is just like that - joyful.

In spring, the park is full of cherry blossom. According to the guidebooks, whole families can be seen strolling through the public orchards and nature reserves along the Tsurumi River. The Toin Gakuen Symphony Hall, on the other hand, hosts classical concerts, and izakaya pubs and yakiniku barbecue restaurants operate in the area, which is surrounded by numerous factories and university campuses. What a place to live in...

▌ E-4000

MANUFACTURER writes about his new amplifier as follows:

The E-4000 integrated amplifier has emerged from separate amplifier technologies. The preamplifier section features AAVA using ANCC to allow for volume adjustments that maintain high levels of vibrancy. The power amp section employs balanced transmission utilizing the instrumentation amplifier principle to drive noise suppression to its limit. The E-4000 is equipped with a four-fold parallel push-pull configuration of power transistors driven in Class AB in the output stage to extract every last ounce of potential from the speakers and create soundscapes filled with subtlety.

⸜ 180W/ch integrated stereo amplifier E-4000, → www.ACCUPHASE.com, accessed: 8.01.2025.

I asked MARK MASAOMI SUZUKI, Accuphase’s CEO, for details of this project.

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⸜ A few simple words…

鈴木雅臣 MARK MASAOMI SUZUKI
General Manager

⸜ Engineers involved in the design of the E-00, (from left) Miyajima-san, Nakamura-san and Itoh-san • photo: Accuphase

» KAZUO SHIMADA • mechanical design
Mr. Shimada has been a veteran engineer at Accuphase for 40 years and has designed the E-406V, E-407, E-450, C-2800, A-60, A-48, and other models. He recently took a DENON DP-51F record player out of storage, which he bought as a student, and is now enjoying the collection of 80's Japanese pop records he amassed during that time.

» TAKAYUKI MIYAJIMA • Electrical design: Pre-amplifier, Power-amplifier, and Sound quality design
Mr. Miyajima is a 39-year-old engineer who is currently in the prime of his life. His past works include E-700, DC-1000, AD-60, DAC-60, and others. He recently switched from a 2006 Nissan Lafesta to a 2007 Citroen C6 and is pleased with the ride quality provided by the C6's Hydractive 3-plus suspension.

» TAKEHIKO NAKAMURA • Electrical design: Microprocessor Assembly, Software programming, and More
Mr. Nakamura has been with Accuphase for 32 years and currently supervises the electronic circuit design department as general manager. His past works include E-460, E-560, E-700, C-2850, P-7500, and others. Recently, his daughter lives away from his home. As a father, he is happy to see his daughter growing up but also feels lonely. ●

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DEVICES BY THIS COMPANY PRESENT THEMSELVES as a point of arrival in the development of this particular art project. As always, the color is the most important thing - the gold front, made of anodized aluminum. The second distinguishing feature is the large power indicators, here in the form of VU meters, placed under the tempered glass, along with LEDs indicating the status of individual sections. And then there are all those knobs and buttons hidden under a hinged flap. Accuphase offers some of the most functional devices on the market, and at the same time does not want to show off with this feature wealth.

FEATURES • The device offers as many as eight line inputs, two of which are balanced (XLR); one of the inputs is a recording loop with an unbalanced line output. We can also feed the power amplifier directly with a balanced signal. As usual, the user can later (or from the start) equip the E-4000 with one or two optional cards. One of them is a digital-to-analog converter. It can be one of three models – DAC-60 / 50 / 40. Vinyl fans can get an MM/M phono preamplifier card (AD-50 / 30 / 20).

The volume control and input selection can be adjusted using the large, comfortable knobs, which have a resistance that gives the impression of operating a serious industrial product. There are additional manipulators under the flap. These include tonal control, loudness, phase, mono, adjusting balance between channels, switching on individual speaker outputs, as well as selecting the way the recording loop works. There is also a headphone jack on the front panel - it hides a full-fledged headphone amplifier. The speaker outputs are doubled and are really convenient to use.

TECHNOLOGY • From a technical point of view, we find most of what we find in the more expensive models of this company, although in a less complex form.

The preamplifier is based on the AAVA (Accuphase Analog Vari-gain Amplifier) circuit, developed by this manufacturer in-house. It is a circuit that regulates the signal level and replaces the classic potentiometer. Since the music signal does not have to pass through resistance in it, changes in impedance at its output are eliminated, regardless of the position of the volume knob. This results in a high signal-to-noise ratio and low THD. In this circuit, the voltage signal is converted into a current signal, regulated as in professional mixers, and then converted back into a voltage signal. The E-4000 uses an unbalanced version of this circuit.

The power amplifier, on the other hand, is balanced and uses a so-called Instrumentation Amplifier, a circuit design that allows for a high common-mode rejection ratio (CMRR) and thus high amplification precision. This is one of the manufacturer's core technologies. The power amplifier uses four pairs of MOSFET transistors in a push-pull configuration, operating in AB Class.

And there is also a power supply featuring a large toroidal transformer and two equally large filter capacitors. The preamplifier, power amplifier and logic circuits utilize separate power supplies. The transformer is encapsulated in a vibration-damping material and shielded.

The remote control is a classic one for this manufacturer, it is reminiscent of the 1970s. The casing is cut out of an aluminum profile and is – obviously – champagne-colored. The buttons are rigid and have a clear point of operation, which is refreshing after the cheap units that come with many, often expensive, devices.

▌ SOUND

HOW WE LISTENED • The Accuphase E-4000 integrated amplifier was tested in the “High Fidelity” reference system. It was compared to a two-box reference amplifier, namely the Ayon Audio Spheris III preamplifier and the Soulution 710 solid-state power amplifier. During the test, the device stood on its feet on the upper carbon shelf of the Finite Elemente Pagode Edition Mk II rack.

During the test, I used the Ayon Audio CD-35 HF Edition SACD player and the Lumin T3 file player as sources. The signal between the SACD player and the amplifier was transmitted via an RCA Crystal Cable Absolute Dream interconnect, and from the file player it was sent via a Siltech Master Crown cable; both interconnects were unbalanced. The amplifier was powered by a Harmonix X-DC350M2R Improved-Version cable, and the signal to the speakers was delivered by a Crystal Cable Da Vinci speaker cable. The Accuphase amplifier drove my Harbeth M40.1 speakers.

» RECORDINGS USED FOR THE TEST ⸜a selection

⸜ TSUYOSHI YAMAMOTO TRIO, What a Wonderful Trio!, Lasting Impression Music LIM DXD 079, Silver-CD (2006).
⸜ KENICHI TSUNODA BIG BAND,Big Band Supreme, Mixer’s Lab/Warner Music Japan WPCL-13559, SACD/CD (2024).
⸜ JOSH JOHNSON, Marvis, Nothern Sly Records/Tidal, FLAC 24/44,1 (2024).
⸜ POPPY JEAN CRAWFORD Glamorous, Somethingcosmic/ Jagjaguwar/ Tidal, FLAC 24/44,1 (2024).
⸜ FLOOR CRY, Happy Together, Floor Cry/Tidal, FLAC 16/44,1 (2018).
⸜ MARLEY BLEU, PHARRELL WILLIAMS, Good Mornin’, Doodles/Tidal, FLAC 24/44,1 (2024).
⸜ HAYATO SUMINO, Human Universe, Sony Classical/Sony Music Labels SICC 30898, BSCD2 (2024).
⸜ SUZANNE VEGIA, Nine Objects of Desire, A&M Records 540 583 2, CD (1996).
⸜ TAMINO, Babylon, Communion Group/Tidal, FLAC 24/44,1 (2024).
⸜ RAPLH KAMIŃSKI, SMOLIK, Cheri Cheri Lady, Universal Music Publishing/Tidal, FLAC 24/48 (2024).

» HIGH FIDELITY playlist: Accuphase E-4000 is available on TIDAL → HERE

I DON'T KNOW WHY, but Accuphase amplifiers “get along” very well with Harbeth speakers. Even though they are mainly designed with Bowers & Wilkins speakers. The closeness I am talking about was evident from the very first bars of ˻ 1 ˺ Another Day, the opening track on the TSUYOSHI YAMAMOTO TRIO album titled What a Wonderful Trio!.

As we read in the accompanying booklet, it was a particularly important release for Mr. Winston Ma, the owner of First Impression Music. Because his hero, the pianist from the label he had admired since the 1970s, when he distributed his music in Hong Kong, not only recorded an album for him, but also wrote three songs especially for it.

The recordings took place in Tokyo's Onkio Hous in the way practiced by TBM, that is, with the musicians playing together in one studio, with the microphones used on most of the albums of this jazz label. The result was brilliant. As Mr. Ma writes, he recorded the sound simultaneously in three ways, analog and two digital: on analog tape, in PCM 24/192 and DXD. In his opinion, the DXD version (24/352.8) was the clear winner and made it onto the album.

With the Accuphase amplifier, it was easy to say why. The device perfectly showed beautiful colors, neither cold nor warm, but wonderfully varied. It also handled dynamics with ease. And it was incredibly spacious. The latter aspect will give E-4000 owners particular joy. Because the amplifier, taking advantage of how well it performs in terms of resolution, color and dynamics, shows the “represented world” in a very, very free way.

The sound sources are clear but not over-emphasized with it. Even with Yamamoto's specific way of playing the piano, which is characterized by strong beats and a sharpened contour, reminiscent of the way Ivo Pogorelić has been playing in recent years. This also helps to show the differences between the recordings. Because when I heard the first drum beats from the album Big Band Supreme by KENICHI TSUNODA BIG BAND, which has just been released by Warner Music Japan, the opus operandi of its producers was immediately apparent.

And in this case, it is about showing an as dynamic presentation as possible, but also a presentation based on a strong mid-bass and lower midrange. Yes, it is a bit of a “bass-heavy” album, as Accuphase immediately showed. But the boost in the 200-400 Hz range was intended to increase the scale, to “slam” listeners with power. It's a big band, for crying out loud, isn't it?! And that's what it sounds like. The fourth album in this series by the band led by Kenichi Tsunoda was digitally recorded in PCM 32-bit, 96 kHz, but the mix was analog and on analog ½” tape. And it is this tape that can be heard well. This is due to its strong saturation.

The tested amplifier had no problems with showing these details. On the one hand, this device is very transparent to the signal, perhaps even more so than the A-700 model, which costs about the same but works in class A. On the other hand, however, it is very consistent in what it does. Perhaps even more so than its “A-class” counterpart. That is to say, transparency and fidelity to the input signal is not an “absolute” that ruins the sound of lesser quality recordings.

I listened to more than a dozen tracks from my list on Tidal using the Lumin T3 player. The difference in quality between SACD played on a much more expensive source and the files was obvious. But it was not unpleasant. I would even say that Accuphase allowed the latter to develop, bringing out the best in them. And all this with a resolving and transparent sound (!).

But also the dark, “studio” recording of JOSH JOHNSON's 2 Marvis, the dirty sounds of POPPY JEAN CRAWFORD's 1 Glamorous or the minimalist, very early 1980s-style cover of the song Happy Together by FLOOR CRY, they all sounded cool, well, I knew why I had included them in my list. But I also realized more clearly that the amplifier, with all its neutrality, has its own agenda.

I think it's about adding weight to the sound. Not at the very bottom, not in the upper bass contours, but in a fairly wide range of the mid-bass. MARLEY BLEU's track Good Mornin', co-written with PHARRELL WILLIAMS, sounded thick and low, with an almost “piling up” lower range. It was open playing, without blurring the contours, selective and clear, and yet “boosted”.

This is probably not what Accuphase's engineers had in mind when improving measurable dynamics, reducing noise, etc., but this is what the results were. The high damping factor helps with this, because the amplifier controlled the Harbeth speakers used in the test very well. It was not a muffled sound, which can also happen in this type of design, but a sound that can clearly be described as controlled. Strong, compact and dense, and at other times, as with the wonderful HAYATO SUMINO’s album Human Universe, delicate, almost sentimental.

WHILE LISTENING TO THE HAYATO SUMINO ALBUM, it struck me that the E-4000 is a bit like a chameleon. It adapts. And it adapts to both the music and the listener. On the one hand, it will surprise many a die-hard technocrat and those who seek technical perfection in sound, because that's how it sounds. But it will also be a prime example of how to achieve a natural sound without using “supports” such as coloration. Yes, there is a boosted mid-bass here, I'll add a slightly rounded high-frequency punch and careful use of the upper midrange. But it's still a very neutral sound.

And yet, when needed, like with ˻ 3 ˺ Caramel, a track from SUZANNE VEGA's Nine Objects of Desire, it sounds warm, even “syrupy”. And yet it is still extremely spacious. The placement of the phantom images on the stage in front of us is perfectly balanced, but it is not stifled for the sake of accuracy either. The wide panorama on Vega's album was shown even wider, and the deep reverberations on the album Human Universe were even deeper.

HEADPHONES • And that bass... I know, I know - it's a deviation from the imagined neutrality, but a deviation that is not so much justified as desirable. The bass is a bit soft, a bit flowing, and yet perfectly controlled. Interestingly, the headphone amplifier sounds very similar. Accuphase equips its integrated amplifiers with dedicated headphone amplifiers that use the sophisticated input circuits of these devices, which offers very good results.

So we get the same big, dense, but also well-differentiated sound, helped by the slight addition of bass and the reduction of treble if we use very transparent headphones. I would even say that the differentiation is even greater in this case, because the transition from Babylon by TAMINO to Cheri Cheri Lady, a cover of a Modern Talking song sung by RAPLH KAMIŃSKI and prepared together with SMOLIK, was very big. The first one was warm, with the vocals right in front of us, the second one was bright, with a lot of reverb. The E-4000 did them justice, and yet they still sounded very cool, even captivating.

▌ Summary

THIS IS HOW I WOULD DESIGN THIS DEVICE: as an extremely versatile amplifier “for everyone”. It's really difficult to achieve, but Accuphase did it. The device is extremely dynamic and spatial. It showed big band pieces with class and panache. But even intimate music, such as the aforementioned Tamino or Suzanne Vega, was very well balanced and saturated.

E-4000 offers a very natural tonality. However, it has its own “something”. It consists of a medium bass boost and gentle treatment of the upper midrange and treble attack. So we get both, precision and something like “protection” against excessive exposure of bright treble. However, if the treble is really strong, like in the aforementioned song by Kamiński, it will come through. E-4000 is not a “cure” for a bright system. It needs balanced elements around it to produce what I am talking about. If we provide it with these, then it will be a blast.

▌ DESIGN

WE'VE ALREADY MENTIONED IT, we talk about it with every Accuphase amplifier, but it can't hurt to repeat it: The E-4000 is a large and heavy integrated amplifier. It works in AB class in push-pull mode. The descriptions of the mechanical and electrical construction and functionality has also be repeated.

ON THE OUTSIDE • Structurally, it is an extremely solid device. Rigidity and damping are achieved by using a thick aluminum front panel and rigid sheet metal forming the other walls. The sides are double-layered, with aluminum elements bolted to the main body. Accuphase has been using its own feet for its devices for years. They are made of high-carbon steel, which is supposed to provide better damping.

All manipulators are made of aluminum, and the transparent plate is not acrylic, but glass – tempered glass. The moving parts are made in such a way that they provide solid support and give the user the impression of using an expensive product. Then there are the colors: orange for the display and the VU meters, red for the LEDs, and green for the logo. It is put together in such a way that it looks both discreet and functional. The display is not large, yet it is perfectly legible from a distance of three meters.

INSIDE • As in the E-700 and most of the other integrated amplifiers from this company, the interior of the E-4000 is divided into three sections by screens: input, power amplifier with power supply, and AAVA and logic circuits. There are also separate boards for XLR and RCA inputs, because the latter have integrated circuits for signal balancing. This is switched in hermetic Omron relays. The XLR sockets are gold-plated, but only the ground of the RCAs is gold-plated and they are soldered, not screwed. This is an element that I think could be improved in the future.

After selecting the input, the signal goes to the front panel, to the signal level control system. As we said, it is the Accuphase Analog Vari-gain Amplifier (AAVA) system. In this case, the circuit works in an unbalanced mode, which is why the E-4000 should be considered an unbalanced amplifier. The signal after the XLR inputs is unbalanced and in this form it is routed through the rest of the system.

And finally, we come to the power amplifier boards. These are screwed directly onto large heat sinks, which do get hot, but much less than in the E-700. This circuit is completely discrete, that is, it is made of transistors. Some components are surface-mounted, but most of them are classic through-hole resistors and capacitors. The latter look very good and are made by companies such as Rubycon and Elna. As they have a higher thermal load capacity, they are designed to work for a long time without drying out (this is the most common reason for the deterioration of sound in old devices).

In the current section, there are four pairs of MOSFET transistors: Toshiba A1944N + C5200N. They are manufactured by the renowned company Vishay. Behind the transistors, there is an output circuit with a Zener diode and large coils that stabilize the operation of this section. They have a square cross-section and are made of high-purity copper. The protection is provided by MOSFET transistors instead of relays, which reduces the output impedance. This part features a separate PCB to which the speaker terminals are screwed - gold-plated, solid, and easy to operate.

The transformer is shielded and screwed to an additional plate, rather than directly to the bottom of the chassis. The screen is extruded, and this is the element that distinguishes the E-4000 from the manufacturer's most expensive amplifiers, which have cast aluminum screens. It is accompanied by two capacitors with the Accuphase logo, each with a capacity of 40,000 μF, produced for the company by Nichicon.

As usual – a perfectly clean construction, well-thought-out topology, and the system uses high quality components, although they are within the “industrial” standard. ●

▌ Technical specifications (according to the manufacturer)

• Maximum output (RMS): 180 W / 8 Ω, 260 W / 4 Ω
• Frequency range:
Line inputs: 20-20 000 Hz (+0 / -0,5 dB),
Power IN: 20-20 000 Hz (+0 / -0,2 dB) @ full power,
Power IN: 3-150 000 Hz (+0 / -3 dB) @ 1 W
• S/N (A-weighted):
line input RCA: 102 dB, XLR: 109 dB
• THD: 0.05%
• Intermodulation distortion: 0.01%
• Damping factor: 800 (8 Ω / 50 Hz)
• Attenuation: -20 dB
• Tone controls:
BASS: 300 Hz/± 10 dB (50 Hz),
TREBLE: 3 kHz/± 10 dB (20 kHz)
• Loudness: +6 dB (100 Hz)
• Headphone output compatible impedance: 8 Ω or more
• Power consumption: 0.3 W (standby), 54 W (idle), 248 W (IEC 60065)
• Dimensions (W x H x D): 465 × 181 × 428 mm
• Weight: 24.9 kg

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THIS TEST HAS BEEN DESIGNED ACCORDING TO THE GUIDELINES adopted by the Association of International Audiophile Publications, an international audio press association concerned with ethical and professional standards in our industry, of which HIGH FIDELITY is a founding member. More about the association and its constituent titles → HERE.

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