˻ PREMIERE ˼

⌈ BLADELIUS was founded in 1997 in Alingsås, Sweden, and is part of the Bladelius Design Group. Its founder is MICHAEL BLADELIUS, one of the most renowned designers in the world of audio. We are testing his latest integrated amplifier, the ODEN Class-A II. This is its WORLD PREMIERE. ⌋

IT HAS BEEN REPEATED LIKE A MANTRA in every Bladelius product review, but there is no way around it: Michael Bladelius is one of the most interesting figures in contemporary audio industry. As we wrote in our review of the first version of the Oden integrated amplifier (Mk I, more → HERE), he started at the age of thirteen, worked for Nelson Pass, then at THRESHOLD, graduated from college in California, where he also wrote his doctoral thesis, devoted to audio amplifiers, and in 1994 he started working on his own, designing devices for CLASSÉ AUDIO and ULTRA ANALOG. In 1997, he founded his own company – Bladelius.

Impressive, isn't it? Just like his latest amplifier – and amplifiers are what the company specializes in – the Oden Class-A II, which we would like to present to you. Its first version was introduced in 2020 and, as Mike wrote to us at the time, it was preceded by ten years of work. It would seem that such an experienced, efficient, and capable designer as he should be able to complete such a project in a year, or maybe two, if we take into account the need to conclude agreements with suppliers and subcontractors. And yet... Clearly, the aim was to create a reference device, a kind of summa scientia of a given time and of himself. Thus, model “II” took another five years of work.

▌ Oden II Class-A

BLADELIUS AMPLIFIERS are named after figures from Germanic mythology, known mainly from Scandinavian sources. Odin occupies an important place in it as one of the most prominent gods, king of Asgard. He is associated with wisdom, healing, death, the gallows, knowledge, war, battle, victory, magic, poetry, frenzy, and even the runic alphabet; he is depicted as the husband of the goddess Frigg. Mike Bladelius writes:

In the old Norse mythology ODEN was the King of all Gods, the wisest, most powerful and the creator of mankind by giving the gift of life to ASK and EMBLA. This Swedish made integrated amplifier represents all the accumulated experience that we at Bladelius have come to learn throughout the centuries. With its twin gigantic toroidal power transformers, it generates an impressive 150 Watts at 8 ohms in pure Class-A (...) symbolizing the uncompromising design and quality.

FEATURES • The device is a fully balanced design, which the manufacturer refers to as “True Balanced,” from input to output. It offers as many as seven XLR line inputs, two of which are designed for balanced sources, while the remaining five, when using adapters, can work with unbalanced signals. There is also a blank port used when a digital-to-analog converter and audio file player module (board) is added. The device also offers two pairs of XLR outputs – from the preamplifier section and a so-called “pass-through.” There are single speaker connectors on the rear panel as well.

Controlling the device is simple and enjoyable. The volume is adjusted using a silver knob with a rounded front, and the active input is selected using a small button; the second button turns the amplifier off. Information about the volume and the selected source is displayed on a clear, white OLED display. Although the amplifier operates in class A, which means it gets very hot and consumes a lot of energy, we do not always listen to music intently. In such cases, to minimize power consumption, we can change the operating class in the menu from full A to AB, with the first watts operating in class A.

The amplifier is controlled by a rather impractical plastic remote control. It resembles the unattractive remote controls from the 1990s. However, you can purchase a metal Bladelius remote control, which is attractive and fits comfortably in your hand. In my opinion, it should be sold together with the amplifier.

TECHNOLOGY • So, we already know that the Oden Class-A II (Oden II for short) is an integrated amplifier. Oden II is the second version of the device that we tested in the past. This device weighs 85 kilograms and measures 450 x 210 x 550 mm, making it extremely compact and “powerful.” It offers 150 W per channel at 8 Ω and 300 W at 4 Ω, all in class A.

One of the secrets behind such high output are two “giant” toroidal transformers, as emphasized in press materials, and a large capacitor bank’s capacity of 260,000 µF, which, according to Mike, ensures “dynamic, silky smooth sound with extraordinary transient response.” Instead of a few large capacitors, Mike used many smaller ones – an increasingly popular strategy promoted years ago by the German company ASR. The power supply is supposed to be a kind of “power plant”, from which the amplifier draws its power, and the small capacitors provide a faster impulse response. Fast diodes in discrete rectifier bridges are also supposed to help.

Mike Bladelius's designs are guided by the philosophy of “Simpler is Better.” Oden II therefore has a single stage of amplification at the input. Hand-selected, matched JFET transistors operate in a foldback cascade circuit. According to Mike, this improves the operational stability of the amplification, and both channels operate in an “identical manner.” And that's not all – all subsequent units of the amplifier are also supposed to be identical.

Combined with current feedback and a DC servo mechanism operating outside the signal path, this translates into “exceptional linearity and lightning-fast response,” according to the manufacturer. And further:

ODEN II provides a seldom found truly balanced design without ground as reference for highest possible performance, (...) which gives a very linear performance regardless of the level of playback.

The ODEN II housing is made of non-magnetic materials (mainly aluminum, including screws), which reduces electromagnetic interference. The unusual heat sinks are noteworthy. Instead of classic “fins,” there are massive modules with vertical openings, somewhat reminiscent of what D'Agostino proposed years ago, and which was adapted in Poland by the Krakow-based manufacturer Divaldi.

At first glance, the Oden II amplifier looks similar to the first version, but it is actually a different device. The chassis is now truly high-end, makes a good impression, and the connectors used are of high quality. The clear display, that makes information visible from a considerable distance, really helps with operation.

▌ SOUND

HOW WE LISTENED • The Bladelius Oden Class-A II amplifier was tested in the High Fidelity reference system, where it was compared to a split system consisting of an Ayon Audio Spheris Evo tube preamplifier and a Soulution 710 solid-state power amplifier. The device was placed on Acoustic Revive RST-38H platforms, which were placed on the floor – unfortunately, it did not fit on the rack. The amplifier drove Harbeth M.40.1 speakers, connected with Crystal Cable Da Vinci cables.

The analog signal source was an Ayon Audio CD-35 HF Edition SACD player and a Sforzato DSP-05 EX file player with a PMC-05 EX master clock. For connections, I used Acoustic Revive Triple-C balanced interconnects. The amplifier was powered using a Harmonix X-DC350M2R Improved-Version cable.

ALBUMS USED FOR THE TEST ⸜ a selection

⸜ NAT ‘KING’ COLE, The Nat King Cole Love Songs, Master Tape Audio Lab AAD-245A, Master Gold-CD ⸜ 2015.
⸜ BLUR, Blur, EMI Records 7243 8 55562 2 7, CD ⸜ 1997.
⸜ OSCARS MOTETTKÖR, Cantate Domino, Proprius/AudioNautes Recordings AN-2104-UHQ, UHQCD ⸜ 1976/2023.
⸜ MA on SA, M•A Recordings, SACD/CD ⸜ 2006.
⸜ SLAYER, Live Undead, Roadrunner Records/Metal Blade Records MBCY-9009, EP, SHM-CD ⸜ 1985/2009.
⸜ JAN JOHANSSON, Jazz På Svenska, Megafon/Heptagon Records HECD-030 E, CD ⸜ 1964/2005.
⸜ CHET BAKER QUARTET, Chet Baker Quartet, Berclay Disques/Universal Classics & Jazz UCGU-9074 ⸜ 1955/2024.

THERE ARE SEVERAL COMMON FEATURES shared by the best amplifiers currently offered by audio companies. These are: smoothness, resolution, rich tonal palette, and dynamics. We get all of this with the Oden II. But it is not these elements that catch our attention when we turn it on, but rather the absolute lack of mechanicality in its sound. This “non-mechanical” constant made itself felt from the very first notes of Nat King Cole's album The Nat King Cole Love Songs, released in 2015 by the Chinese company Master Tape Audio Lab on Master Gold-CD.

Let me remind you that this is a material copied onto a CD-R straight from the master tape – probably the production tape. Its sound is incredible in terms of smoothness and naturalness. The tested amplifier not only showed it off to great effect, in all its richness, even excessiveness of half-tones and color and dynamic nuances, but also gave an accurate insight into the different recordings. This is a compilation, recorded from various master tapes, containing tracks with different recording methods, masters, etc.

It's easy to „get carried away” with it, oh so easy! I've heard it many times with amplifiers that tried to do something at all costs and emphasized dynamics, selectivity, and finally the “presence” of sound. The Swedish device, with ease but also with absolute confidence, overcomes these trifles and presents us with a large, pastel-like but also saturated sound. This is yet another recent example of a solid-state amplifier playing with the lightness and subtlety of SET tube amplifiers, while also having a mass and scale that those designs are (physically) unable to provide with any speakers, as I see it.

As I’ve said, Oden II played Cole's album with confidence. There was delicate, nice, warm treble that lacked nothing, because it was also well-separated. There was also an excellent bass foundation. In this type of recording, where there are acoustic instruments, this is reflected in the scale of the recording – which is really large here. It is also the depth of the stage, which does not converge far “there” into a small point, but which has height and width across a large part of the depth of the stage. The foreground is the most important here, including the vocals, of course, but they are not taken out of context or imposed on the listener.

These advantages are always there and do not depend on the type of music we listen to. Because even Blur, the band's album released in 1997, sounded perfect. According to both musicologists and scientists specializing in recording techniques, this album is considered a breakthrough for the band. What is important for us is that it was recorded on an OTARI computer system with 16-bit and 48 kHz parameters; more → HERE. Let me remind you that this was the first system of its kind to be treated by producers and sound engineers as “digital analog tape.” This is also how the albums recorded on it sound, including the one in question.

The tested amplifier played it perfectly smoothly, but also aggressively – a combination characteristic of the songs on the album. It's a bit in the spirit of The Beatles, as well as Lennon from the days of the Rock’n’Roll album. Oden II perfectly sensed this duality, i.e., the grit on top and the melody underneath, and translated it wonderfully into sound. It added a strong kick drum beat, as in ˻ 3 ˺ Country Sad Ballad Man, a crazy track with distorted vocals and loud but warm electric guitars.

For “Swede,” the transition between the patinated solo guitar and the clear, resonant acoustic guitar was easy, even natural. It's a great album and it was wonderful to listen to. It was a bit bright, but also warm – that's the kind of recording it is. The clarity of Damon Albarn's vocals was surprising, because it is, after all, a fairly warm, dark recording. And yet there were no problems with this, either in the powerful, dense tracks, such as ˻ 4 ˺ M.O.R., nor in the more upbeat ones, such as ˻ 5 ˺ On Your Own.

At this stage, I was already curious about how the amplifier actually interprets space. Both of the above-mentioned albums were recorded in a studio – in the case of Blur, in its entirety, and in the case of Nat ‘King’ Cole, partially, because the recordings took place with the entire band and the singer singing along with them (behind a “screen”). In any case, they gave me the feeling of being in another world. The device projected the sound in such a way that it permeated the air in the room and mixed with it imperceptibly, as if they were one.

It was exceptionally captivating because it was so imperceptible. But that's what Oden II is like – it eludes being “pinned down” with ordinary descriptions. That's probably why even the reference recordings of classical music allowed me to immerse myself in the presentation rather than just “listen” to it. And this is not hyperbole, I am not exaggerating, because that's how I felt with this amplifier throughout the entire listening session. With it, the space is enormous, expansive in all directions, but it is impossible to point out its “details.”

I am referring to the sound that flows and fills the room, with which the title track opening the album Cantate Domino builds up, demonstrating the excellent, balanced dynamics of the device. Both the organ, shown in a large perspective, and the choir were, on the one hand, vivid, warm, and fluid, and on the other, concrete and selective. But selective not in terms of sharp edges, but in terms of tonal differentiation. The version of this album released on UHQCD by Fabio Camorani is perfect in this respect, which the Swedish amplifier emphasized even more.

But even in the super-intimate, super-purist recordings of M•A Recordings, made with two microphones, I heard a lot of warmth and powerful dynamics. The opening track of the sampler MA on SA by Eduardo Egüez in ˻ 1 ˺ Prélude from Partita in E minor sounded sensational! There was the warmth of the handpan playing in the background, there was the penetrating quality of Egüez's singing, and all this in an incredibly focused, “compacted” space.

▌ Summary

I could sum it all up in one expression: super natural sound. I would add the words “unbelievable” and perhaps “wonderful,” and if I got carried away, even “miraculous.” This is an amplifier that allows you to listen to music comfortably without feeling that you are missing out on anything. The Accuphase E-800S, another device of this type and class, sounds a little more expressive, but that does not mean that the Oden II lacks detail. The amount of detail, nuances, half- and even quarter-shades of color is incredible with it.

And all this is served up with finesse and ease. It is remarkable to see how technologies blamed for “bad” sound, such as digital technology, and in this case transistor technology, have matured and bear fruit in the form of amplifiers such as the Oden II. This device performs the same way regardless of how loud we listen to it. Each album has its own SPL level at which it was mastered and at which it should be listened to, but the Swedish amplifier somehow bypasses this, and whether we listen quietly or loudly, nothing is missing from the sound.

That is why Bladelius Oden II is such an outstanding device – a device I could live with and listen not only to Cole, not only to classics or the wonderful CHET BAKER from the Chet Baker Quartet, but also to Blur, Oasis or Slayer. So let me say it already: the amplifier will receive the award for us, the Statement in HIGH FIDELITY in the Polish Edition 2025, awarded jointly by the magazines hifistatement.net (Germany) and “High Fidelity” (Poland); the award ceremony will take place in Warsaw during the Audio Video Show 2025 – congratulations! ●

▌ Technical specifications (according to the manufacturer)

Power output: 150 W / 8 Ω || 300 W /4 Ω
THD: <0.01%
S/N: >125 dB
Frequency response: 1 Hz-100 kHz (+0/-3 dB)
Inputs: 2 pairs of true balanced, 5 pairs of Balanced Inputs (may be used with unbalanced equipment via adapter)
Outputs: 1 pair of true balanced line out, 1 pair of true balanced pre-out, 2 pairs of heavy duty Loudspeaker Terminals
Dimensions (W x H x D): 450 x 210 x 550 mm
Weight: 85 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.

→ www.AIAP-online.org