Meeting #49



Accuphase, the company was born in 1973, and initiated its business (in August 1973) with a system consisting of a P-300 power amplifier, C-200 preamplifier and T-100 tuner. Those were times, when the main, and actually the only, high quality pre-recorded carrier, was the vinyl LP (reel to reel decs were used mainly to record from radio or LP). Everything changed with the CD format, that became the first, and probably the last, digital system based on a moving carrier. And although the year 1982 is give as the year the standard was born, Accuphase thinks differently, and states that the year the standard was actually accepted was 1986. This can be due to the fact, that in that year Accuphase presented their first CD player. A reference one.

As I wrote many times before, I am a big fan of Japanese aesthetics in art and technique. Hence my esteem for the magazine Stereo Sound, that being issued in Japanese gets translated by the tested companies very quickly. But already the layout of the magazine is quite admirable. Now back to the main topic: this magazine, being issued for forty years now, in 1978 started to award extremely prestigious yearly awards. There are not many of those, and are treated like movie Oscars. All Accuphase reference players earned those awards. All of them.

1986: Components Of The Year (COTY) – DP80+DC81
1988: Components Of The Year (COTY) – DP80L+DC81L
1992: Components Of The Year (COTY) – DP90+DC91
2000: Components Of The Year (COTY); Golden Sound – DP100+DC101
2006: Grand Prix 2006 – DP800+DC801

Almost 100% of the tests are listening sessions of devices being currently in production. This is dictated by iron logic, that suggest to deal only with products available in retail, having a set price and available service. That is the reason I think that the comparison we are going to make is unique. Courtesy of the Polish distributor of Accuphse, Mr. Robert Szklarz from the company Nautilus Hi-End, who provided us with the DP-100+DC-101 and DP800+DC801 systems for our listening sessions. Frankly speaking, he has shown quite some courage, as the main idea of HFOL and also the Krakow Sonic Society is being uncompromisable. And while we stand down from describing mediocre devices in our magazine, in case of the meetings all the listened devices have to be described.

We have also provided a DP90+DC91 system. The latter came not from nowhere. It turned out, that in Krakow, in a short period of time, two such systems appeared, bought independently, and the decision was based on listening experience only. It seems, that the older devices from this brand are highly prized (this is also true for McIntosh, Mark Levinson or Marantz). This given set is especially willingly put against newer players from Accuphase, and this due to two facts: this is “clean” Compact Disc – with the afterthought “SACD is rubbish” – and because this was one of the last players employing multi bit converters. Now Delta-Sigma ICs are present everywhere, that are multi bit devices (eg. 5 bits), but those are operating based on different principles. And are much cheaper to manufacture.

Comparison of two players is uncommon, but listening to three subsequent generations of players is an absolutely unique experience. To add character to the session, the listening was conducted in surrounding of other Accuphase devices, including vintage ones. We have described the system earlier, while comparing those Japanese player with the Prime from Ancient Audio (coverage – HERE). Before we come to the listening session, we have to go through some technology – we are talking about evolution of digital technologies here. And I think it is worth it..

DP-80+DC-81/ DP-80L+DC-81L/ DP-90+DC-91/ DP-100+DC-101,
czyli trochę historii

DP-80 was named Compact Disc Player, although it could only output a digital signal – today this name is reserved for integrated devices. DC-80 was the Digital Processor – the company is true to this terminology even nowadays. The drive and servo system were controlled by an 8-bit microprocessor. The drive was seated on ceramic supports. The converter was really revolutionary, because its heart – the D/A converters were made from discrete components, or at least the company materials state it so, and this means no ICs were used. I am however not fully sure this was the case, as photographs of the insides show four ICs – separate for each channel and each branch of the balanced signal. In addition the digital section was separated from the analog by means of 34 optical couplers. Two times oversampling. And first time besides the 75Ω S/PDIF an optical interface was used (EIAJ – now called TOSLINK).

In November 1988 a modified drive and processor were presented, with “L” suffixes to the names. The main change was the drive, now able to read 3” singles, that was mounted on an additional aluminum frame (still a Sony device). Also two EIAJ optical outputs were added. The converter also received an increased amount of inputs, but the main change was the addition of 32kHz and 48kHz sampling frequencies used in DAT recorders. Similar to the basic converter also here the device is “discrete” (as stated by Accuphase), but complying to the global trends, the company used a 20-bit 8 times oversampling version, and because each bit is separately transferred to the analog section 42 optical couplers were used.

In December 1992 a new version of the player reached daylight, bearing the symbols DP-90+DC-91. The main change was the appearance of the devices, clearly coming in the 90-ties. The company literature states, that the real change was due to the creation of the MMB circuitry – Multiple Multi Bit, meaning that in each channel a few D/A converters, filters and analog devices were used, and their outputs were later summed. The advantage of such topology is, that the quantization errors are lowered (equalized), sound noise ration is higher and the distortion is lower. This is still a 20-bit device, but the input was adjusted to accept 24-bit signals. The preferred ling is still optical, but now with a proprietary transmission protocol HPC - “High Performance Connection” - and using glass connectors. The throughput of the link was 150Mb/s (compared to 10Mb/s in EIAJ). In parallel a balanced electrical connection was developed (wit XLR connectors) in the same standard. The drive was equipped with a “balanced circuitry for power supply and servo” (a patent used until today), and the 3mm motor axis was placed on sapphire bearings. The source the drive came from is still Sony. In March 1998 a slightly modified version of the processor was presented named DP-90B.

The SACD system was developed and marketed jointly by Philips and Sony. Introduced in 1998 became a hit only in Japan. Now, 9 years after being introduced, from the mass market point of view, SACD is a dead format. However something changed in the attitude towards it, as the Philips and Sony design was accepted by audiophile record companies and declared the best alternative for LPs. And probably such status will remain – audiophile niche. But this will allow it to be popular for a long, long time. Anyway, 2 years after Sony, in 2000 a new reference from Accuphase hits the store shelves, the DP-100+DC-101. It does not take much thinking to see, that this is an almost perfect copy of the top player from Sony, the SCD-1 (1998). A top-loader, with the drawer shifting sideways, it received a proprietary Accuphase solution, the DC-101 converter. Similar to the DC-91 many parallel D/A converters per channel were used, but the multi bit architecture was abandoned in favor of the Sigma-Delta. Although, from the perspective of the SACD 1bit converters, operating at sampling frequency of 2.8224MHz are ideal, then from the perspective of the CD this is not necessary a step in the right direction. Todays S-D converters with a few bit architecture are in general very good, but we have to remember, that 7 years of development in the digital world is equal to about 21 years of the analog (I am slightly generalizing here). Let us mention, that the ICs come from Analog Devices, those are the AD1853. The main link is the optical HS-Link, that transfers also the DSD signal from SACD discs.

For our entertainment, let us add, that from the first amplifier from 1973 much changed in the Accu engineers approach to the basic ideas of designing the devices. So we can read in the leaflet accompanying the system 300/200/100:

Basic Engeneering Policy

„Some followers of the ultra-wide frequency response claim, that the frequency response from DC to 10000kHz is the basis to achieve high quality sound. The truth is, that no source of sound can reproduce frequencies above 20kHz. In addition if we record a square wave (a wave with infinite amount of harmonics) with the best possible quality, on a tape with 15ips, above 7kHz only the basic sine wave can be recorded. Even at 7kHz, the basic wave, including the 3rd harmonic giving a result sine wave at 21kHz cannot be registered.[..] We believe, that a frequency response in the boundaries 20Hz – 20kHz is sufficient.”

As (reportedly) Heraclitus said: “Everything flows'...

And finally the new reference. Carrying the symbols DP-800+DC-801, it comes back on the predecessors 80/81. This time the changes touched the insides deeply. Because I tested those for the Audio , I'll repeat what I've written about their construction:
“And looking at the newest combination it cannot be seen directly what has been changed inside, as much as all the systems differed from each other inside, they were similar on the outside. One of the biggest decisions was the transfer from the CD to SACD taken between the 90 and 100 series. It is not a simple addition of the capability of playing back the SACDs, but a complete change of philosophy, it is a different reader (DVD), different error correction and its programming, clocks and finally converters. With the new times, starting with the 100 series, also the times of Delta-Sigma converters came, at first one bit, then few bit (up to 5) in place of the classic multi bit devices. The first ones are much cheaper in production and can be made much more precise, as the resistors inside can be cut with a laser. Unfortunately there is also a Dark Side of the Force – the Sigma-Delta converters do not excel at high levels of sound. Their most frequently called upon flaw (speaking in sonic terms) is the lack of sound depth and overemphasized smoothness. Listening to subsequent “beefed-up” digital sources, based mainly on those converters, I must say, that this is not the full truth, and much depends on their application.


Anyway, the system DP-100+DC-101 was not for long in Accuphase portfolio, because it stayed in production almost as long as the previous one, and fits in the general Accuphase model turnover timelines, but it seems, that it could have stayed longer in the offerings. Despite the early implementation of the SACD standard, the engineers of Accuphase managed to write the drive coding and construct the converter so well, that there was nothing to worry about. But as Accuphase was ahead of its time in terms of mastering the silicon chips, the spirit of the time caught it in terms of the drive, when Sony finished manufacturing of the high class SACD drives (Accu used the most expensive one, that could be found in the two earliest devices from Sony, the SACD top-loaders). This was a problem, and a grave one. Starting a few years ago, the Accuphase engineers started to create their own drive. Probably some kind of DVD was the basis for it, but not much remained of it in the end. The first visible change in the DP-800 is the fact, that it carries a classic drawer, and is not a top-loader any longer. The first idea, is that this is a step backwards. But when we look at the drive, the perspective will change. Accuphase went in the direction that Esoteric (TEAC) went earlier with the NEO-VRDS drive, that is a completely modified Sanyo drive. And so, the DP-800 drive has a very heavy, rigid bridge connecting the sides of the drive, and the clamp is located in an additional brass ring on top. The drive has a low center of gravity, as it is located on very heavy and solid plate from some alloy (top-secret). The servo, named “Traverse Mechanism” is floating, meaning it is separated from the main chassis by means of viscous dampers. When we press the “Open” button, the drawer will open silently, with grace and self confidence, just like an aristocrat, that can be recognized in the middle of the street by his flawless manners.

Except for this everything in the DP-800 reminds the latest incarnations of Accu devices – the servo is powered by a balanced power supply, meaning that both branches, plus and minus are active, we have two transformers – one for the section spinning the disc, and one for the servo. Also the rest of the power supply is quite worked out as we have six separate power supplies. This is important, as we can transfer the signal out not only by the traditional S/PDIF RCA (unfortunately the AES/EBU is missing), but also by the proprietary HS-Link *High Speed Link), characterized by very high bandwidth and high transfer speeds up to 1923Mbps. From the electrical side the link is quite ordinary, it is a typical CAT5. This kind of interface is used by Denon in its Denon-link and by the tested some time ago player from North Star Design (but in this case it uses a simpler I2S protocol). One can see that this drive is dedicated to the DP-801 converter, as the compatibility with older converters, where the HS-Link was optical or XLR, was not kept. There is much going on here, and this is just a drive, an element quite boring in its predictability... Let us only mention, that the PCB traces are gold plated (this will be also the case in the converter), and the whole device is supported by special feet made from highly carbonated steel (‘Advanced High Carbon’), that are to kill vibrations by turning them into heat. And one more thing – on the amber colored display CD-Text and SACD-Text can be recalled. The display is with good contrast and readable even from larger distances.


As we can say a lot about the drive, about the converter we can just point to the basic facts, the whole is namely very complex. And there is really a lot to talk about, because Accuphase DC-801 represents truly the second generation of devices processing the DSD signal, a generation that was not revealed in consumer products before Sony killed its brainchild. As it is known, the base for the SACD format is the DSD (Direct Stream Digital) stream with the parameters: 1bit and 2.8224MHz sampling. It was however developed as data archiving format, and adapted for audio purposes later, so it is very hard to process. First generations of studio equipment had convert the DSD signal to PCM of high density and on the output convert it back to DSD. This was regarded as pure nonsense, losing the advantages of the one bit signal on the way. So the second generation of the studio devices works with at least 2 times higher sampling rate (5.6448MHz) or even higher. This allows for more breathing room, and the engineers from Accuphase gives a powerful tool. In consumer devices, the system 2xDSD was introduced by the company Sharp in a series of devices with digital PDM amplifiers, but only here we have its creative implementation (and I don't mean creative accounting...)

In the Accuphase nomenclature this solution is called MDSD (Multiple Double Speed DSD). Because this is one of the most interesting practical solutions to the SACD disc signal, it is worth to devote some words to it. First of all the signal coming from the transport is decoded (the transfer is done in coded form), and then it is oversampled to 5.6448 MHz/1bit. Next step is the processing of the volume of the signal, and we go to world of the analog. This is not an easy way, because at the very beginning we have an IC, that multiplies the signal by factor seven and every signal is delayed by one cycle. A so prepared signal reaches eight identical D/A converters from Analog Devices, the AD1955 (four two-channel devices) and later to eight branches that do the I/V conversion and filtering. Only in the end the signals are summed, and due to the equalization of the decoding and conversion errors the output signal is much more precise. Also due to the parallel conduction of the analog branches the noise is minimized and and dynamics bettered. This solution is used by Accuphase for years and is called MDS++(Multi Delta Sigma of third generation), but here the delay was added. The case is about the fact, that in standard parallel designs, after summarizing a low-pass filter must be used. Here the inherent quality of MDSD is that it works as an 8th order filter, without any additional circuitry. So on the output a simple Butterworth filter can be used, with ideal phase response, and thus without any ringing in the signal at an impulse. We have an almost direct conversion of the DSD signal to the analog signal – a dream of the designers.

Looking at such excess, other elements, like a worked out PLL loop with the company name Ultra Jitter Free PLL++ does not impress as it should... And the DC-801 is not only a DSD converter, but a high class PCM (up to 24/96) converter too. The signal from the CD has a much shorter path – after decoding it goes directly to the converters, it is summed and goes to the output. A big problem for many balanced devices is that to the output two separate buffers and sockets are connected – one for the balanced signal and one for the unbalanced one. Accuphase claims, that measurements and listening test have confirmed, that this leads to compromise in the top end devices, and we do not want that, that's for sure. One of the advocates of standing down from combining XLR and RCA is Balanced Audio Technology, a company that in its top range devices uses only balanced connections. And to achieve maximum compatibility of their converter Accuphase employed fully separate analog branches (starting just behind the converters) for the RCA and XLR section.

Now a few words about the physical buildup of the converter. Similar to the transport it is enclosed in a large, incredibly rigid, because composed of many layers of overlapping aluminum sheets, flats and casts, chassis. Its front brings to mind devices from early 70-ties, because it lightens it from the Midas look of the 80' and 90', and still keeps the brand look. In the middle we find a big company logo (interestingly, the official Accu logo is red, and the one on the converter is green...), and to the side of it there are two amber alphanumeric displays, on the right one the input name is displayed – and we can choose from two optical TOSLINK (S/PDIF), three electrical RCA (S/PDIF ), electrical XLR (AES/EBU) and electrical CAT5 (HS-Link). Let us also mention that we have two digital outputs – TOSLINK and RCA (for PCM signal only) and a digital loop, eg. for the acoustics corrector DG-38, we tested some time ago in Audio. On the left side of the logo we have a volume indicator: Accuphase devices have a sophisticated, worked out digital volume control. Analog outputs are in both the balanced and unbalanced version. Everything looks perfect, so it is a pity the RCA sockets aren't gold plated...
The insides is split into three sections. Half of the enclosure is taken by the digital section, with two shielded transformers (classic EI) and power supplies for this section. The second half, separated by a thick shield, is occupied by two, also separated by a shield, converters, one for each channel, with their respective power supplies. Both PCBs are made from high quality Teflon base, the traces are made from double layer OFC copper (made according to military specs) and are gold plated. The signal is routed from the digital PCB by quite long shielded cables. It is quite surprising, but in their top offerings Accuphase is using quite “run of the mill” passive elements. The engineers asked about that, claim that the problem of common parts is in the spread of their parameters, and not in the absolute quality. It is better – according to them – to spent money on finding the ideal parameters and pair them (in this case eight identical elements must be found). That is the reason, why nothing on the PCBs draws our attention, besides ideal order and cleanness. Let us also mention, that the power supplies are extremely elaborated, with large capacities – but instead of large capacitors many smaller were used, what should minimize the impedance of the circuit and help in the overload speeds.”


And frankly speaking it is not by chance, that I cited such a long quote from the test, because I tried to show how much the way of thinking about the digital sources has changed, and underline, that only starting with such devices, besides the top offerings from EMM Labs and dCS (both tested by me for Audio some time ago) we can talk about SACD in the high-end class and combination of the top SACD and CD.

We started the listening session listening to some CDs one after another, starting from the oldest design. This took about 40 minutes. Even such short test showed clearly, that the 100/101 system was significantly worse than both other systems. The differences between 90/91 and 800/801 were clear and first opinions were constructed in our heads, but one thing was clear and beside the question the model 100/101 was significantly standing out. Its sound was a bit damped, compared to the other systems, and had a significantly lower resolution. Also the stage was shallower and had lower density. Maybe I am a bit unfair, because listening to it without reference, and taking into account the quite low price it reaches on the Internet fairs, I must say that the sound is perfectly acceptable and even pleasant. Let us add, that it plays SACD discs very nicely. But... It was clearly audible, that it is a step backwards. In the very beginning of our meeting we assumed, that nobody will issue his opinion before the end of our meeting, when we will have a covert vote. But the disproportion between the devices was so clear, that I stood up and proposed to narrow the rest of the comparison to the 90/91 and 800/801 sets. Because all attendees nodded their heads we devoted the rest of the test to compare the oldest and newest offerings. After an hour everybody received a piece of paper and was requested to write down his favorite. After reading the sheets it turned out that three voices were for the 90/91, three (including mine) for the 800/801, and two people could not decide for one of the offerings, seeing advantages and disadvantages in both of them.

The first thing that strikes in this result, is the fact, that a digital system from fifteen years ago can stand up and compete head to head with a modern system. Incredible! In general time for the digital world flows much faster and it could have been expected that the new reference would destroy the old one. And nothing like this happened here. Even better – everybody agreed, that although the differences in character are large, the quality understood as the “class” of the device, is actually the same. The preferences were put on paper, but those were not in terms of better-worse but a representation of our tastes and understanding of sound. Because there was a system in between, we can say that (at least for Accuphase, but I think this is true for a broader range of devices and we can generalize) the change of two constants made it necessary for time to pass to accommodate the changes. I am thinking about the change from multi bit converters to Sigma-Delta and the change of drives from CD to SACD (DVD). It is hard to imagine, how would audio look like, if those old techniques from the 90/91 system would be developed until today without glitches. Although the CD drives underwent some progress and the CD-Pro2m (now in the version CD-Pro2LF, RoHS compliant) is a very good unit, but this a kind of stand-alone anomaly, persistence of somebody in he Philips board, who thinks it is worth to make such devices. And though many companies, most of all Sony, stopped the production of drive units. TEAC designed the multiformat VRDS-NEO and I believe only C.E.C. with its belt drive is doing something in that area.
In case of the converters the situation is clear: now nobody is manufacturing any multi bit converters, in traditional terms, meaning 16, 20 or 24 bits ICs, only Delta-Sigma devices are available. Accused of little coherent, low resolved sound they have to go through a long way, to at least level-up with the old technique.

The differences between the two players can be brought to a different way in treating the musical matter, different interpretation of the happening. 90/91 is the master of resolution, both in the micro and the macro scale. It seems, that the 800/801 supplies the sound less separated. The older model plays with an incredibly open, direct sound, that is quite merciless for the recordings. One can also notice the incredible dynamic capability of the device – from the quiet murmurs of the piano up to the powerful tutti of an orchestra were reproduced without a trace of compression or softening if there was a sharp edge then it was shown as such. Frankly speaking one could talk about a magnifying glass put on the disc. In cheap devices such character ends in headache, because everything is shrill and annoying, but here we have incredible cleanness and the mentioned dynamics. Due to that combination of characteristics we got a sound, that in some way is emulated by the most expensive dCS system I tested some time ago. And regardless what anybody thinks or says, we have to salute the Accuphase, although having its years – esteem is here an involuntary reflex here.

Being true to the detail is not everything in the audio. Together with the passing time, after listening in my system to many top digital systems and correlating its sound with top vinyl systems I come to the conclusion, that privately I search for something else in the sound. For me the fluency and saturation, timbre, that is not only a precise drawing but also a continuum of harmonics is more important. I am not saying that the older system is worse, but I am just presenting my preference. It would seem, that with this level of refinement, with that money the differences should be smaller and good sound means just this: it is “natural”. The truth is that really – the higher we get, the differences seen as deviation from naturalism are smaller and smaller. But with refinement comes another layer of analysis, namely the character of the sound. Here is not one recipe, because every time it will be a mechanical reproduction of a recording (let us remember, that we are not talking about the reproduction of an event, but its registration), that is an approximation, a way of trying to get a similarity between the reproduced sound and the natural sound. Here, the goal of absolute sound (meaning some imagined value) can be reached in many ways. And it was so in this case. The new Accu system sounds in an incredibly fluent, organic way. We do not have as much information about details as from the older model, the dynamics is slightly less explosive, but, at least in my opinion, the newer model sounds more natural, maybe not as neutral as the 90/91, but for me it was closer to the spirit of music.


Audio is an art of compromises, regardless of the price of the devices. With the hi-end it is about different compromises than in lower price ranges. Here we have to decide what is our philosophy of the reproduced sound, what are we looking for in the music. This makes the differences in the votes for the 90/91 and the 800/801. Regardless of personal choice it must be said, that the older Accu is an incredible piece of engineering and for the price that is to pay for it, it is an absolute bargain. It is an example, that a brand is a value that should not be understated, and that solid companies, staying firmly on the ground, create kind of art pieces, things, that one will not have to be ashamed of for many, many years. And I am sure, that in the future, the 800/801 system will have a classic status, just as the 90/91 has now. And I did not mention one thing – this player is absolutely brilliant as a SACD. Only the split EMM Labs system plays such discs equally well.

System used for the listening tests:
  • Digital sources – Accuphase DP90+DC91; Accuphase DP100+DC101; Accuphase DP800+DC801
  • Preamplifier – Accuphase C-290V
  • Power amplifier –Accuphase A-50V x 2
  • Loudspeakers - B&W Matrix 801 v3
  • Cabling: Velum
  • Power: Accuphase PS-1200


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