Manufacturer: Accuphase Laboratory, Inc.
The E-600 is the follower to Accuphase’s flagship integrated amplifier, the successful E-560. The manufacturer decided to change the name from E-five-hundred to ‘600’ to mark the amazing progress they managed to achieve. The new naming scheme is to symbolize a change that is something more than just releasing a new model.
hat much we learn from the company literature. It would be needless to repeat that the change of its flagship integrated is really SOMETHING for Accuphase. Usually it is the most expensive, most advanced products that “haul” the rest of high end manufacturer’s lineup around. The A-200 “anniversary” monoblocks reviewed by me some time ago, and before that the two-piece DP-900/DC-901 SACD player, confirmed Accuphase capabilities as a manufacturer, at the same time ushering in a new sonic direction (the review appeared in “Audio” magazine). That is at least how I understand it: a direction for sonic fullness and density. But let’s get back to the integrated amplifier. Apart from its flagship design, Accuphase has always devoted most of time and energy to its most expensive integrated amplifiers. Although they lack the advantages of two-piece designs, they promise something the latter can’t: they do not require extra cables or space. For many music lovers both of them are as important as the sound itself.
To understand what you get with the E-600, you need to know what was “under the hood” of both its predecessors as well as to know the context of these changes. When I opened up the E-560, my first thought was about “streamlining” of the starting design. The E-560 turned out to be assembled almost entirely in surface mount technology, while previously it was predominantly traditional through hole assembly. For many manufacturers, the transition from the latter to the former reflects a technological leap. It is not always positively associated in the audio world, due to the higher noise and distortion of SMD components as well as their inferior thermal properties. The way I see it, Accuphase simply had to take a firm step in either direction. The arrival of the E-560 coincided with a sharp drop in Japan’s exports and was actually forced by it. The high cost of raw materials, which the country is largely importing, combined with the Yen’s high exchange rate hurting overseas sales resulted in such increase of the production cost of electronic devices, including E-550, that you needed to think really hard in order not to run a business at a loss, and forget about making a profit. In this situation, the only good option seemed to be an escape forward to newer models, featuring an improved design and significantly higher price. This is how the E-560 came to be.
The E-600 is a completely different story. Do you remember the comparison of the Accuphase E-250 and E-260 integrated amplifiers in the last year’s February issue of "High Fidelity" (No. 106, February 2013, see HERE)? If the E-550 were the starting point, the E-600 would be one more step further from it than the E-260 was from the E-250.
Changes from the E-560
The most visible is the change of power output meters referred to earlier. In my opinion, it is for the worse, but I talked to a few people who had previously owned the E-550 and E-560 and found this forgivable and even desirable. On the plus side is an alphanumeric LED display indicating volume level and significantly improving unit’s ease of control. The amplifier is visibly higher, slightly deeper and heavier.
Albums auditioned during this review
Class A amplifiers are the jewel in Accuphase’s crown. They constitute the core of its lineup, even if the models operating in the more efficient Class AB are simply more numerous. This way Accuphase implements the commendable objectives set before the designers of this type of amplifiers: to operate in the most linear portion of the characteristic curve and to avoid the problem of crossover distortion resulting from the signal crossing over the zero point. Crossover distortion can be alleviated to some degree, as demonstrated by Cambridge Audio in the so-called “Class XD”, featuring crossover displacement where the usual crossover point no longer occurs at zero volume but at a significant output level. Even in this case, however, it is still Class AB, with certain characteristics corrected.
If you have read my review of the Iridium 20 amplifier from Tellurium Q, you know my view on the usual stereotype associated with Class A. In my opinion, it is so confusing that its evaluative value disappears. It seems that closer to the truth is what is represented by the Accuphase A-60 and A-65 monoblocks. It’s a very fast and clean sound with powerful dynamics. This would find confirmation in auditions of the best tube amplifier I know, Jarek Waszczyszyn’s Silver Grand Mono monoblocks.
With 30 Watts per channel under the hood there is not much ground to expect stratospheric volume levels. This is basic physics and there is no way around it for now. However, the fact that the output power doubles at half the impedance load and then doubles again down to 2 Ohm, and even 1-Ohm operation is possible (although the latter with music signal only, not a continuous sine wave), tells us that this is a powerful tool. Those who have heard the Soulution 710 power amp at my place and seen its massive body, usually remark casually that it’s probably 500, or even 1000 Watts. Actually, it is “only” 125 Watts per channel. Except that it doubles at a lower load impedance. I hear exactly the same thing with the E-600: its dynamics seem unlimited. Children of Sanchez, the track famous for its dynamic range, sounded exeptionally open, fast and agile. While on the E-560 the price for it was a shallower midrange, its successor sounded the same across the whole range. Its sound was full and selective at the same time, no matter if it played quiet or loud.
It was only when I pushed it really hard with Anja Garbarek and Massive Attack tracks that I heard the limits of what it’s capable of. It’s about the depth of bass. The amplifier had a low, full sound with great control over the whole range and without even a moment’s hesitation. However, there was a point when the lowest bass became slightly withdrawn. It might have perhaps extended even deeper yet there wouldn’t be – so I imagine – the kind of smoothness and coherence it offered now. Once I knew what to look for, I was also able to pinpoint the moment when Haden’s double bass started to sound slightly lighter on the E-600. That was stretching it, though, and would be difficult to confirm without this kind of push. Vangelis on Blade Runner, which has rather substantial “weight”, did not betray any specific departure from what I heard on the reference system.
With all the other albums, even on such large speakers as the Harbeth M40.1 it will be hard to say that the E-600 does NOT show something. Not because it’s a perfect sound but because it is so well “made”. It is possible to enumerate its characteristic features and point out which are shared with the E-600 predecessors. It’s just that everything here is combined in a new way. A strong midrange and treble attack now shows as fast rise transients without any blurring, followed by full sound of considerable weight. A contoured bass now translates into full control over the speakers.
The included DAC does not look as attractive at first glance. The number of “gears” in the MDS++ circuit is limited and the D/A converter is an older design, not the recent ESS Sabre chip. The whole board is actually rather small. It would be a mistake, however, to treat the DAC as a whim or less significant addition intended for BD players and digital TV tuners. A comparison with the reference player showed the lower resolution, saturation and smaller soundstage of the DAC-40. But I was prepared for it. What was new for me was how long it took to compare the two against each other, to know exactly what's going on. The tonality of the optional Accuphase DAC was slightly darker than that of my Lektor AIR, lacking some treble of the latter. But that’s probably intentional. With all its velvety and rich sound, the E-600 does not fully “accept”, if I may say so, poorer produced tracks. If treble is slightly overly-contoured and vocals are audibly compressed, as on the latest (really beautiful) album by Martyna Jakubowicz with covers of Joni Mitchell songs, the result is the hardening of top end attack. The DAC-40 smoothes out and darkens this exact sonic component. Hence, the E-600 + DAC-40 combo offers an even smoother and more pleasant sound. In my opinion, its quality matches that of the DP-410 player from the same manufacturer, given, of course, that we pair the latter with a top notch CD transport. And that means that we’re talking here about an outstanding “option” that allows to save a lot of money. While more expensive components will provide a wider soundstage and better sense of intimacy with the “body”, the DAC-40 does that with such grace that I can easily imagine people who will sacrifice that for convenience and in order to save money. Attention: the USB input sounds just as good! The sound may lack some of the precise image outlining of the CD, but is saturated and smooth.
While the DAC-40 is more than a mere “add-on”, the headphone output should be treated that way. I'm sure that Accuphase engineers were extremely serious about the included headphone amplifier. However, they weren’t able to come up with something that would be a match for dedicated headphone amplifiers from one of the specialist manufacturers. Resolution, selectivity and smoothness – they are all here. What’ lacking, though, is a full-bodied sound that can be heard through the speakers, and the bass is quite light. If all you want is to use your headphones only occasionally – and the Accuphase headphone output will be just great for that – you will be better off with those that have a saturated bass, such as something from AKG or Beyerdynamik. Sennheisers and HiFiMANs were not anchored enough in the bottom end.
Two-piece audio systems have a solid engineering basis. Separating preamplifier and power amplifier power supplies, and their mechanical separation bring certain benefits. Naturally, the downside is the need for additional cables, which is quite expensive – I assume here that we care about the best possible sound, and not a simple coupling of the two components. The problem of such systems is, however, the preamplifier, which is almost always the weakest link. If I were to set up such a system consisting of products from of any manufacturer, I would spend twice as much on the preamp as on the power amp. That is reality, unfortunately.
Accuphase has been very slow to change its amplifiers’ enclosure design. Many of the design solutions introduced in the early models can also be found in the latest units. The distinguishing feature of this manufacturer is the front panel made of golden anodized aluminum. Although in its history there have been silver and even black units, it is gold finish that has survived the test of time and is associated with Accuphase.
The interior of the components from this Japanese manufacturer has not changed for years: it features metal screens that reinforce the entire enclosure and separate the individual modules from each other. I've seen the solution copied dozens of times by Chinese manufacturers. However, each time I was sure that what I saw was just a copy, a fake that may have been a tribute to the original but would never be even close to it. The differences were usually in details like the type of finish, the inferior components used and assembly arrangement, and the overall lack harmony. However, they were the reason not to treat it as a development but only as an attempt, not always successful, to copy the original.
The preamplifier is mounted on three PCBs, separate for RCA inputs, XLR inputs and volume control assembly. The latter is the newest version of the Accuphase proprietary AAVA circuit, originally developed for the flagship C-3800 preamplifier. The AAVA volume control includes V/I converter, CPU volume attenuator and I/V converter. It is fully analog (AAVA stands for Accuphase Analog Vari-gain Amplifier) and has been developed by the manufacturer for several years. All preamplifier sections are built on integrated circuits.
The DAC-40 is an option board to be inserted in one of the two available slots on the rear panel that are identified in the input selector as OP 1 and OP 2. It is housed on a single PCB. The S/PDIF inputs sport the AKM AK4118 digital receiver, and the USB input is built on the Tenor TE8802L USB receiver and converter – a great chip, used for example in the earlier SACD players from Marantz. From the currently selected input the signal goes to two Burr-Brown PCM1796 DACs, operating in dual-mono. I/U conversion and analog filtering and amplification is handled by the JRC4580 op amps. The signal is processed in two parallel paths (per channel), to implement Accuphase proprietary MDS++ technology. All active components and resistors and some capacitors are assembled in surface mount technology. Only the capacitors in the signal path are polypropylene and electrolytic through hole units. The back of the board is fully shielded with a steel plate that also stiffens it. A solid piece of work.
Technical Specifications (according to the manufacturer)
- Turntable: AVID HIFI Acutus SP [Custom Version]
- Cartridges: Miyajima Laboratory KANSUI, review HERE | Miyajima Laboratory SHILABE, review HERE | Miyajima Laboratory ZERO (mono) | Denon DL-103SA, review HERE
- Phono stage: RCM Audio Sensor Prelude IC, review HERE
- Compact Disc Player: Ancient Audio AIR V-edition, review HERE
- Multiformat Player: Cambridge Audio Azur 752BD
- Line Preamplifier: Polaris III [Custom Version] + AC Regenerator, regular version review (in Polish) HERE
- Power amplifier: Soulution 710
- Integrated Amplifier: Leben CS300XS Custom Version, review HERE
- Stand mount Loudspeakers: Harbeth M40.1 Domestic, review HERE
- Stands for Harbeths: Acoustic Revive Custom Series Loudspeaker Stands
- Real-Sound Processor: SPEC RSP-101/GL
- Integrated Amplifier/Headphone amplifier: Leben CS300XS Custom Version, review HERE
- Headphones: HIFIMAN HE-6, review HERE | HIFIMAN HE-500, review HERE | HIFIMAN HE-300, review HERE | Sennheiser HD800 | AKG K701, review (in Polish) HERE | Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, version 600 - reviews (in Polish): HERE, HERE, HERE
- Headphone Stands: Klutz Design CanCans (x 3), review (in Polish) HERE
- Headphone Cables: Entreq Konstantin 2010/Sennheiser HD800/HIFIMAN HE-500, review HERE
- Interconnects: Acrolink Mexcel 7N-DA6300, review HERE | preamplifier-power amplifier: Acrolink 8N-A2080III Evo, review HERE
- Loudspeaker Cables: Tara Labs Omega Onyx, review (in Polish) HERE
- Interconnects: Acoustic Revive RCA-1.0PA | XLR-1.0PA II
- Loudspeaker Cables: Acoustic Revive SPC-PA
- Power Cables: Acrolink Mexcel 7N-PC9300, all system, review HERE
- Power Distributor: Acoustic Revive RTP-4eu Ultimate, review HERE
- Power Line: fuse – power cable Oyaide Tunami Nigo (6m) – wall sockets 3 x Furutech FT-SWS (R)
- Power Cables: Harmonix X-DC350M2R Improved-Version, review (in Polish) HERE | Oyaide GPX-R (x 4 ), review HERE
- Power Distributor: Oyaide MTS-4e, review HERE
- Portable Player: HIFIMAN HM-801
- USB Cables: Acoustic Revive USB-1.0SP (1 m) | Acoustic Revive USB-5.0PL (5 m), review HERE
- LAN Cables: Acoustic Revive LAN-1.0 PA (kable ) | RLI-1 (filtry), review HERE
- Router: Liksys WAG320N
- NAS: Synology DS410j/8 TB
- Stolik: SolidBase IV Custom, read HERE/all system
- Anti-vibration Platforms: Acoustic Revive RAF-48H, review HERE/digital sources | Pro Audio Bono [Custom Version]/headphone amplifier/integrated amplifier, review HERE | Acoustic Revive RST-38H/loudspeakers under review/stands for loudspeakers under review
- Anti-vibration Feets: Franc Audio Accessories Ceramic Disc/ CD Player/Ayon Polaris II Power Supply /products under review, review HERE | Finite Elemente CeraPuc/ products under review, review HERE | Audio Replas OPT-30HG-SC/PL HR Quartz, review HERE
- Anti-vibration accsories: Audio Replas CNS-7000SZ/power cable, review HERE
- Quartz Isolators: Acoustic Revive RIQ-5010/CP-4
- FM Radio: Tivoli Audio Model One