SoulNote P-3 Special Edition Line Preamplifier

SoulNote is a Japanese company, founded in 2004 by the ex-director of Marantz Nippon, an engineer, Mr. Norinaga Nakazawa. It specializes in the construction of solid-state amplifiers, phono preamplifiers and digital sources from the middle and upper price range. We are testing its P-3 Special Edition linestage.

Mr. Norinaga Nakazawa, co-founder of the SoulNote brand, is one of Japan's best-known engineers. In 1982, while working for Marantz Japan, he perfected the design of a high-end cassette deck and oversaw the design of the company's iconic CD player, the CD63. By establishing CSR (Corporate + Social + Responsibility), together with other former Marantz engineers, he focused on a younger generation of designers.

The first device that was introduced, the Compact Disc da1.0 player with an output stage and a power supply without feedback, was developed with their participation, including Mr. Hideki Kato.

After graduating from Tottori University, he joined NEC where he worked in the Audio Engineering department, and when NEC retired from the audio industry, he joined Nippon Marantz. There he was the head of the team designing non-feedback amplifiers and the LHH series for the Philips brand. In 2005, he was recruited by Mr. Nakazawa and joined the CRS. He worked, as he writes in his Facebook posts, on the development of such devices as: dc1.0, da1.0, sa1.0, sc1.0, SA710, SC710 etc.

A turning point in his career came in 2016 when he became Chief Engineer for SoulNote, and since then he has been overseeing everything from production planning to design to "sound quality studies" and promotion. As he recalls, his patron commissioned him to do only one thing: he had to make SoulNote the best audio brand on the market. As he writes in one of the posts on Facebook:

Well, it seemed like an exorbitant request, but I had an idea of how this could be implemented. All you had to do was solve the biggest puzzle in the audio world - the discrepancy between specification and sound quality—and then use it to achieve unprecedented sound quality using methods that other manufacturers did not reach for (or could not reach for) and present them to the world. Today it seems to me that I know most of the reasons for the discrepancy between the specification and sound quality. And this is the basis of the current SoulNote design philosophy.

A strong statement. When following the development of the brand, it is impossible not to notice that it is not unfounded. At some point in 2018, the tests of the new generation SoulNote devices, developed under the supervision of Mr. Kato, began to appear in the Japanese magazine Stereo Sound, and to Europe, and thus to Poland, they first arrived at the end of 2019. As it turned out, the delay was caused by a long procedure of obtaining approval of new products and their reconciliation with European regulations. Since 2016, the following devices have been introduced within its framework:

2016 ⸜ A-1, C-1, E-1, A-0
2017 ⸜ D-1, A-2, E-2
2018 ⸜ D-2, D-1N
2019 ⸜ S-3
2020 ⸜ S-3 ver. 2, P-3
2021 ⸜ ZEUS (D-3, Z-3, X-3, RCC-1), S-3 Ref.

Let me remind you that so far we have tested the A-2 SE integrated amplifier (test HERE; HF № 189 | January 1, 2019), and exactly two years later an excellent player of optical audio discs, the S-3 v2 (review HERE; HF № 189 | January 1, 2021). In May 2021, we looked at the D-2 E digital-to-analog converter (review HERE; HF № 205 | May 16, 2021 | PL). Looking at all these devices, it would probably not be an exaggeration to say that the P-3 Special Edition line preamplifier is the "jewel in the Mr. Kato's crown."

P-3 SPECIAL EDITION

The tested preamplifier belongs to the flagship SoulNote series, marked with the letter "3." It also includes the S-3 v2 SACD player, file transport, DAC and clock, which form the benchmark file player called ZEUS, as well as powerful monoblocks, shown at this year's audio show in Tokyo.

The P-3 SE seems to be thought out from start to finish, not only from the point of view of the electrical system, but also the mechanical one. This is a line preamp. Period. There is no DAC, streamer, headphone amplifier, phono stage, and no Bluetooth connectivity. It has only one task: to prepare an analog signal from a signal source before feeding it to a power amplifier. So it switches inputs, attenuates the signal, buffers it and amplifies it, then sends it out. As it turns out, this is an extremely difficult task.

MEASUREMENTS vs LISTENING

It is rare for Japanese companies, but Mr. Hideo Kato decided to publish elaborate texts on his projects. Reading them, I have the impression that it is a kind of an essay that is also a meditation, intended for both the readers and the writer himself; is a type of writing that is highly valued in Japan.

Among the seven chapters published so far, the Discrepancy between specs and sound quality particularly caught my attention, which is devoted to the discrepancy between measurement results and sound quality. Let me remind you that it is written by a classically educated engineer with many years of experience in corporate world.

There is a strong statement at the outset: "In the audio industry, everyone realizes that sound quality cannot be judged solely through the prism of specifications, more precisely—static specifications." Outside of the audiophile industry, this may seem strange and it's hard to believe that in times of "scientific universalism" people are able to hear changes that are not measured. Nevertheless, Mr. Kato believes that there is an important place in audio for measurements, only that not in the traditional approach.

As an example, he gives a typical situation where an engineer makes a correction to a layout and gets better measurements and thus changes the sound. He/she almost always assumes that it means a "better sound." For this reason, bosses and sales departments of large companies will not allow the production of a device that has worse measurement results than the previous one, no matter how good it sounds. This is the reason why the progress in terms of sound quality in audio has not been constant.

To support this claim, he cites a story from his own life. As a student, just like most college students, he didn't have much money. He loved music, so as a hobby he built amplifiers and loudspeakers for himself. At first he didn't have any measuring devices, but he didn't care, because if he liked the sound, nothing else mattered much. In addition, he says, his amplifiers sounded much better than his friend's high-end devices.

One day, a distortion measuring device fell into his hands. What he measured was terrible. So he tried to improve the design of the amplifier so that it fared well in the measurements. Thanks to various improvements and improvements in measurable values, he achieved excellent results. But… but when he listened to the music, he was completely bored with it. So he began to wonder why it happened, and he spent the 40 years thinking about it. Only then did he come to an absolutely iconoclastic conclusion: what if the measurements do not really translate into sound quality? Today, he adds, he can finally explain it. And the best explanation, I think, are the devices from the "2" and "3" series, including the tested preamplifier.

P-3 Special Edition is a large, very solid, well-made device weighing 25 kg (!) and measuring 454 x 174 x 430 mm. It is a balanced dual mono design working in class A, without feedback. It offers four balanced XLR inputs and four unbalanced RCAs. The signal can be sent out via three XLR balanced outputs and one RCA unbalanced one. Inputs no. 4, both XLR and RCA, can be converted to home theater inputs, i.e. without volume control. On the back panel there are also sockets for communication between devices of this company.

The volume control is executed with a convenient knob above which a multi-section display featuring LED modules is placed. The display can be turned off, which the manufacturer recommends. The information will then appear for a while after you change the volume or input. The knob is coupled to an encoder, and the latter controls a discrete attenuator, consisting of unique relays and resistors. The RSR-2-12D relays closed in metal housings bear the SoulNote logo, because they are custom-made for this company.

The selected input is signaled by red LEDs. Interestingly, one selects the XLR and RCA inputs separately. There is one more LED under the power switch, which glows blue if the power cord is properly connected. If this is the case, it means that the signal ground of the left and right channels (they are led separately) is disconnected from the device's chassis. This is the most desirable situation. You can change it with a switch on the back panel, then the ground is common and the LED changes color to amber.

After this short introduction, you can already see that we are dealing with a highly original device. Or just take a look at it and you will realize the same. Its chassis is made of aluminum. It has a well-thought-out design, in which the goal was to dissipate vibrations as quickly as possible from the transformer to the surface on which the device is placed. Therefore, the spike visible from the front is screwed not to the bottom part of the housing, but to the platform on which the transformer stands

The device stands on the wooden platform that comes with it, and the top cover is "floating" because it is not screwed to anything. All of this helps to control, channel away and dampen vibrations. The same is achieved by heavy, stiff aluminum plates, where the sockets connectors are screwed to—all of them, including the power socket. The set includes a metal remote control, it is solid, heavy and it looks good. We can use it to control not only the preamplifier, but also the SACD player from this company, so there are a lot of buttons on it.

Finally, let's come back for a moment to the matter of measurements. The clash of practice and theory, as well as Mr. Kato's unique experience, resulted in extraordinary results. Everything he said above about measurements is the basis of his actions. Therefore, its devices work in class A and with no feedback. Nevertheless, he managed to obtain incredible measurable results: an extremely wide, rare seen frequency response between 2 Hz and 1 MHz (!), very low total harmonic distortion (THD) of 0.0015% and extremely low noise, at the level of 13 μV (20 kHz).

SOUND

HOW WE LISTENED

The SoulNote preamplifier was placed on the top, carbon shelf of the Finite Elemente Master Reference Pagode Edition MkII rack. It stood on spikes, which were put on the wooden platform that was delivered together with the device. I have to admit it looked great. It was connected with the Ayon Audio CD-35 HF Edition SACD player using the Siltech Triple Crown interconnect, and with the Soulution 710 power amplifier with the Acrolink 8N-A2080III EVO interconnect.

The device was compared to the Ayon Audio Spheris III active tube preamplifier and the TVC-05 Special Edition passive transformer preamplifier from the Polish company VINIUS AUDIO, in A/B/A listening sessions, with A and B known.

Recordings used for the test | a selection

Dominic Miller & Neil Stacey, New Dawn, Naim naimcd066, CD (2002).
Patricia Barber, Companion, Premonition Records/Mobile Fidelity Sound Lab UDSACD 2023, SACD/CD (1999/2003); more HERE.
Billie Holiday Body and Soul, PolyGram/Mobile Fidelity UDCD 658, gold-CD (1957/1996).
Ella Fitzgerald & Louis Armstrong, Ella and Louis, Verve/Lasting Impression Music LIM UHD 045, UltraHD CD (1956/2010).
John Coltrane & Johnny Hartman, John Coltrane & Johnny Hartman, Blue Note/Esoteric ESSB-90138, SACD/CD (1963/2015) w: Impulse! 6 Great Jazz, "MasterSound Works", Blue Note/Esoteric ESSB-90133/8, 6 x SACD/CD (2015).
Frank Sinatra, Sinatra at the Sands, Reprise/Stereo Sound Reference Record SSVS-011/014, "Stereo Sound Reference Record", SACD + CD (1966/2019).
Music For A While. Improvisations on Purcell, perf. by Christina Pluhar, L'Arpeggiata, Erato 4636203, CD + DVD (2014).
Claudio Monteverdi, Ottavo Libro Dei Madrigali, perf. by Concerto Italiano, Rinaldo Alessandrini, Opus111 OPS 30-187, CD (1997).
Mike Oldfield, Tubular Bells, Mercury Records/Universal Music LLC (Japan) UICY-40016, Platinum SHM-CD (1973/2013).
The Rolling Stones, Exile on Main St., Atlantic/Universal Music Company (Japan) UICY-40001, Platinum SHM-CD (1972/2013).

A thing that, as it seems to me, will hit you from the start of listening to the P-3 SE preamplifier will be how "non-mechanic" the sound is with it. When I say 'mechanic' I mean something that causes us to pay attention to the imperfections of the sound recording equipment, to the non-musical elements so much that they interfere with listening to the music itself. This is not the case with the tested preamplifier.

I would even say that thanks to the applied solutions, both systemic and mechanical, Mr. Kato and his team have brought the presentation to the point where the presentation is so silky, so smooth that we perceive it without any obstacles, without thinking about the sound as such. Even if we are very much focused on this element of artistic creation, which is the recording process and its reproduction, we are more focused than others.

And I don't mean rounding the sound or smoothing it. The silkiness and smoothness that I am talking about result from, it seems to me, not taking something away—and rounding and smoothing are just subtractions—but from filling the sound with micro-information that enrich it. It is thanks to this filling that the P-3 SE sounds so smooth. It sounds so silky thanks to, let's say it, the high resolution.

It's not that details and subtleties are missing. Because the fact that Patricia Barber in the opening sequence of Black Magic Woman from the Companion holds her voice as long as you can also hear the double bass played with a bow, is clear, hand moving along the fingerboard of a guitar in Rush Hours from the New Dawn by Dominic Miller and Neil Stacey, is similarly obvious. Normally you can't hear it that much, but the producers apparently wanted us to hear it, wanted it to be an element of the presentation, enriching and completing it.

Recorded in the same year, 1956, for the Verve label and produced by Norman Grantz, the Billie Holiday's Body and Soul and Ella and Louis by Ella Fitzgerald and Louis Armstrong sound completely different. Lady D.'s disc is brighter, the vocal has less reverb, so it is closer and a bit more insistent. On the other hand, the duo's album is deep, dense, with much more emphasis on the lower midrange.

The Japanese preamplifier showed these differences very well, because—as I have already mentioned—it is a very resolving device. But it also showed them in his own way. This is something that I emphasize during each test of the company's products, and which did not start with new designs in 2016, because it was present before. It is about what could be called "showing the better side of the recordings." I am intentionally not talking about "beautification," because that is not what it is about, it is a preamplifier that is very transparent in terms of sound. Rather, I think about extracting what is most important in music and conveying it in such a way that we do not lose sight of it.

It seems that apart from resolution, equally important in creating this presentation is the harmonics saturation in such a good way that the sound does not seem artificial, but natural. This is why the vocals of Fitzgerald and Holiday, and then Johnny Hartman's from the John Coltrane & Johnny Hartman and Frank Sinatra's from the live album Sinatra at the Sands, had so much charm. Contrary to appearances, these are not technically perfect recordings, but they are excellent in capturing the emotions, dynamics of the event, that is, the things that build the "image" of the event in our head.

It is also helped by focusing our attention on the midrange. This is the most important range of our audible spectrum to which we are evolutionarily sensitized. Each distortion of its part of the band triggers a subconscious fear in us. We'll never get to that point with SoulNote. Not only is this sound pure, i.e. uncolored, but also natural, meaning one that nothing has been taken away from.

In addition, the way of building the band's edges also helps in achieving it. They are, in short, less energetic than the midrange. I am not saying that they are withdrawn, because they are not. Both the double bass from the Barber's album and the guitars from the Miller & Stacey duo's album were strong, full and dense. It was similar with the treble. But it was also noticeable that they have a different role to play than in such designs as the Octave Jubilee, Vinius audio TC-05 Special Edition, or the Ayon Audio Spheris III.

Each of these preamplifiers sounds different, although they all sound great. The P-3 Special Edition SoulNote goes in yet another direction. On the one hand, it opens the sound more than the reference preamplifier, and on the other hand it promotes the main sound sources. Both with the Music For A While. Improvisations on Purcell, with Christina Pluhar as the soloist, and with male voices on Claudio Monteverdi's Ottavo Libro Dei Madrigali performed by Concerto Italiano, the reverbs had less weight than the vocals.

In the reference system, both albums sound more distant from the listener, with a lower and darker sound. The P-3 SE opened the upper midrange more forcefully, but at the same time smoothed everything out and pushed it towards me. This is its own feature, and the procedure is carried out efficiently and with proper sensitivity. There will be less selectivity and depth in this sound, and more "presence" and vividness, despite the fact that the whole thing seems quite warm.

This is a feature that will be present with every recording, which tells us that this is a proprietary feature of the preamplifier. So all albums will be sparkling and ultra-smooth. Not only classical music and jazz, but also rock. Because the large instruments from Mike Oldfield's Tubular Bells and powerful performance from The Rolling Stones' Exile on Main St. had exactly the same features.

In both cases it was also clear that at the very bottom of the band the sound was slightly emphasized and did not have such precise edges as with other top solid state preamplifiers. So it is not the energetic bass that I know from Mark Levinson or Naim devices. In this respect, it was closer to the Octave Jubilee preamplifier. So one may say, it belongs to devices where the contour is not as important as filling of the sounds, and the precision of the drawing has a smaller role to play than the precision in rendering harmonics.

SUMMARY

The longer I listed to the SoulNote preamplifier, the more sure I was that the P-3 SE sounded like a pure tube preamp. It had all the features of a smooth, fluid, color-rich tube. Its space was excellent, but it did not lead the sound far into the stage, but rather widened and stretched it around me. The dynamics was fantastic and gave the taste of being close to live instruments.

The Japanese preamplifier is specific in this presentation, which means it will be easy to identify its features and decide if this is what we are looking for. If I tried to compare it to CDs, I would say that it sounds like remasters on Platinum SHM-CDs. Which is deep and incredibly addictive. The reference preamplifier would, in turn, be closer to XRCD and SACD discs.

After all, the P-3 Special Edition is a top preamplifier belonging to a group of few devices of this type that really are the "heart" of the system and feel good about it. It does not cover anything, it is resolving, but also has beautiful colors, reminiscent of the colors of the best tube preamplifiers. Its design is unusual in the pursuit of "perfecting" every detail, and its appearance is really very cool. This is a high-end device at a great price.

DESIGN

The P-3 Special Edition is one of the best-built audio devices I know, both in terms of mechanics and electronics. Its chassis has been constructed in such a way as to control vibrations as much as possible. It is made of stiff, aluminum elements fastened with thick beams. The sides are double-layered and the bottom is made of thinner sheet metal. On the other hand, the top cover is also double-layered and it is not bolted on, but rests on three cones. And there are also spikes on the bottom, with the middle one supporting the aluminum structure directly, with one of the transformers bolted to it.

The signal is accepted via balanced Neutrik XLR inputs or the unbalanced RCA ones. There it is switched in the hermetic RSR-2-12D relays in a metal housing, custom-made for SoulNote. The sockets are screwed not directly to the back panel, but to a metal plate, and only the latter, through ceramic—as the manufacturer says: very expensive—washers, to rear the panel. This is a solution reducing vibrations. The IEC power inlet is mounted in a yet different way, because it is placed on a metal plate using pins—it is slight "loose," it is not tightened. Let me add, that it is an excellent Jodelica socket, the ETP-600CU model.

The input section features separate power supplies for relays only. Each of them seems to be supplied separately.

Attenuator

After an input is selected, the signal is attenuated in a unique custom circuit. This is a discrete "L" type attenuator, different from the classic R-2R. It requires more components, but according to Mr. Kato, it is better. Instead of a dozen or so, as many as 156 resistors had to be used. And not just any resistors. These are absolutely unique ones without housing, the so-called "naked resistors." They are to cost up to 200 times more than high-class, classic elements of this type. The attenuator works in 0.5 dB increments and we have 143 of those at our disposal, down to -71.5 dB. Systems of this class are used in telecommunications satellites, and the resistors come from such a design.

As you can see this is a system with an attenuator in the input. It is followed with the gain and buffering circuits. They are based on class A bipolar transistors—also here we can find the above mentioned resistors. The company calls this circuit the Type-R, where the "R" stands for "Reference." This is a revised type of a circuit used in the A-2 amplifier. SoulNote believes that its operation is better than that of an electron tube and it is very simple too—there are only four transistors and eight resistors per channel (in a balanced circuit).

This circuit has a separate power supply, with a huge, 260 watt transformer—there are two of them, one per channel and a third for logic circuits. They are accompanied by large banks of capacitors. There are really many of them and they have a relatively small unit capacity. Mr. Kato believes that each circuit works best with a specific capacity value. Needless to say, it is selected during listening sessions. The power supply in the P-3 SE is larger and more advanced than most integrated amplifiers I've ever seen.

The preamplifier is big, heavy and looks really good. Its design includes solutions which, due to high costs, are used very rarely or not at all in audio. Some are original SoulNote developments. The entire preamplifier is a model of engineering, but aware of its limitations. Way to go!

Technical specifications (according to the manufacturer)