For a digital source I used my MacBook computer to stream Jazz 24 via my DIY Art of Tone 22GA tinned-copper pushback wire USB interconnect to an Mhdt Lab Havana USB DAC.
The Havana was connected to the Acoustic Revive RPT-6 Absolute NCF Power Distributor with an Acoustic Revive Power Reference TripleC NCF AC power cable, and connected to the Oto Phono SE Signature with the superb new Duelund plastic-free RCA DCA16GA tinned-copper interconnects.
For an analog source I used my Classic Turntable Company hot-rodded Garrard 301 turntable in an Artisan Fidelity plinth (photo below), with a SPEC AP-UD1 Analog Disc Sheet turntable mat, a Peter Riggle Audio Engineering Woody SPU tonearm equipped with—what else—an Ortofon SPU Classic GM MkII stereo phono cartridge, stepped-up with an Intact Audio SUT that compliments the Ortofon SPU Classic GM MkII, and a Thomas Schick tonearm equipped with a Soundsmith Zephyr Mk III phono cartridge.
These days I've been doing 99% of my listening with Schick & Zephyr Mk III combination, and all of the vinyl listening impressions presented are with that combination.
The CTC Garrard 301 is plugged into the Acoustic Revive RPT-6 Absolute NCF Power Distributor via the combination of an Acoustic Revive RAS-14-TripleC NCF Power Stabilizer and a Furutech G-320Ag-18 power cable.
Other accessories included two Acoustic Revive RWL-3 Acoustic Conditioners for room treatment, Acoustic Revive RR-77 and RR-888 Schumann Ultra Low-Frequency Pulse Generators, and Acoustic Revive Quartz Under-Boards under the Intact Audio SUTs and the Acoustic Revive RPT-6 Absolute NCF Power Distributor.
Listening Impressions
Micky Seaton told me to give the Oto Phono SE Signature integrated amplifier about 150 hours of run-in time before any serious listening.
My usual method for accumulating run-in time on a component is to place it into my vintage Altec 832A Corona loudspeakers-based music system in my master bedroom, and then let it play the stream from the excellent Jazz24 station in Seattle until it sounds like things are settling in appropriately.
Cold out of the box the Oto Phono SE Signature integrated amplifier sounded a little brash and forward powering my vintage Altec 832A Corona loudspeakers (above), but then it settled down and smoothed out quite a lot around the 150-hour mark, just like Micky said it would.
I then moved the Oto Phono SE Signature integrated amplifier into my main music listening system in my living room with my Duelund-ized vintage "Stokowski" Altec's (below).
I then listened to the Oto Phono SE Signature integrated amplifier with a mix of vinyl and the Jazz24 stream.
The Oto continued to noticeably improve until it was north of 400 hours, after which I experienced one of those "Oh my god!" listening sessions, and decided it had pretty much stabilized in terms of run-in time (although the Oto has continued to subtly improve since then).
I found that if I let the Oto Phono SE Signature integrated amplifier warm up for an hour or so while playing music in the background, before doing any focused listening, it brought the best out of it.
First, allow me to provide you some general impressions of what I heard from the Oto Phono SE Signature, then I'll drill down with some specific examples.
The Oto Phono SE Signature really opened up after the 400-hour mark, with its musical and sonic flavors developing fully, and expressing themselves in impressive ways.
When streaming Jazz24, listening sessions were full of life and light, with the music taking on the vivid sense of live music being played right in front of me, what my friend Yazaki-san would call "real sound."
The Oto's sound was very transparent, natural in tonality, full of rich timbral nuance, with live-like dynamics, and impressive levels of resolution on display.
The Oto's 10 watts can easily drive the sensitive "Stokowski" Altec's to live-like SPL levels with headroom to spare, and I never even got close to using all of the Oto's available power.
The Oto Phono SE Signature always provided me an engaging sense of tempos, beat, melodies, and harmonies that were truly impressive.
By the way, the Oto's phono stage is superb (above), and it is something special. I probably should have brought this up earlier during Andy Grove's description of his design of the Oto, but even though I'm a little tardy in my timing, let me elaborate a little more about it now.
Way back over a decade ago, when I wrote up my review of the Leben RS-30EQ phono stage for Positive Feedback, Hyodo-san told me that he divides classic valve phono stages into two basic design genres: those like the Marantz Model 7 that use negative feedback (NFB) to achieve RIAA phono equalization; and those like the Harman Kardon Citation IV that use no NFB, and use capacitors and resistors (CR) to achieve RIAA equalization.
So, by analogy, if the Marantz Model 7 phono stage was a push-pull amplifier using negative feedback in its design, then the Harman Kardon Citation IV phono stage would be a single ended triode amplifier with no negative feedback.
That's the sort of design difference we're talking about in these phono stage circuits, and why Hyodo-san considers the Harman Kardon Citation IV to be "a masterpiece" of phono preamplifier design, and I wouldn't disagree after listening to a nicely restored one that belonged to my friend Ron Barbee in my own home (below).
Of course, the Harman Kardon Citation IV phono stage is what Hyodo-san modeled his Leben RS-30EQ phono stage after, and I still cherish my Leben RS-30EQ phono stage's musical & sonic performance after more than a decade of listening to music with it.
Well, guess what? If you guessed that the phono stage in the Oto Phono SE Signature is a zero-feedback design with a CR passive RIAA EQ network that is in that same spirit as the classic Harman Kardon Citation IV phono stage or the Leben RS-30EQ phono stage, you would be exactly right.
In other words, the phono stage in the Oto Phono SE Signature is also "a masterpiece" of phono stage design, and I love the fact that it is incorporated into the chassis of the Oto in a truly integrated design.
The phono stage in the Oto is well shielded and dead-quiet, there aren't extra sets of RCAs or interconnects mucking up its performance, it's just pure hot-rod analogue performance direct-injected into the Oto's engine room.
Even with no music playing, and the volume control cranked up to what would be live-like levels with music playing, the phono stage of the Oto Phono SE Signature was preternaturally quiet even on my very sensitive "Stokowski" Altec loudspeakers. That's impressive.
Ok, so what do all those general aural observations of mine about the Oto Phono SE Signature add up to?
Here's the deal, simply put, the level of emotional engagement and musical involvement the Oto Phono SE Signature integrated amplifier provides in combination with my Duelund-ized "Stokowski" Altec's—whether from analog or digital - is unparalleled in my over six decades of listening to music. The Oto is amazing, just like legendary mastering engineer, Steve Hoffman, told me.
The Audio Note (UK) Oto Phono SE Signature integrated amplifier in combination with my Duelund-ized "Stokowski" Altec's has become the "desert island" system of my dreams that I just can't get enough of when listening to music.
This review represents one of those happy situations where a component – the Audio Note (UK) Oto Phono Signature integrated amplifier—is an ideal match to my personal tastes, my overall system setup, excels in both the presentation of musicality and audiophile-style "sonics," not to mention providing superb emotional engagement with the music.
If I were to stop fooling around with audio right now, I could be totally happy listening to this system for the rest of my life. The Audio Note (UK) Oto Phono Signature integrated amplifier pushes all my musicality & sonics performance buttons, appeals to my sense of value and practicality, and makes me feel happy while listening to music with it.
Well, I guess I've enthused enough about my general impressions, so let's drill down into some specific music examples with my usual analysis of the Oto Phono SE Signature's performance in terms of musicality, visuospatial performance, and emotional connection to the music.
First up for a listen was the new two LP set The Complete Plantation Recordings of Muddy Waters that was recently released by Analogue Productions.
If you are at all interested in these recordings, there's a really nice write-up with complementary videos about the album at the link above on the Acoustic Sounds website.
These recordings were made by musicologist John Wesley Work III and folklorist Alan Lomax at the Library of Congress in 1941. They recorded the music using a Presto Model ‘T' Recorder portable disc-cutting lathe onto aluminum and glass-based lacquers on a trip to Stovall Plantation.
These recordings were first released on 78rpm records as part of a five-disc set from the Library of Congress album titled Folk Music of The United States, Album IV: Afro-American Blues and Games Songs.
For the Analogue Productions album, Chad Kassem utilized the original metal disc recordings created by Lomax, which were transferred to 192kHz digital files, which were then used by Ryan K. Smith at Sterling Sound to master the two-LP set of The Complete Plantation Recordings of Muddy Waters for Analogue Productions.
My primary interest in listening to the two-LP set of The Complete Plantation Recordings of Muddy Waters from Analogue Productions was to see how well they compared to the 78rpm recording transfers to CD that were made by Peter's late friend, Anatoly Markovich Likhnitsky, which I described earlier in this article.
The Complete Plantation Recordings of Muddy Waters from Analogue Productions sound really good, are natural sounding, and are surprisingly quiet considering their ancient aluminum and glass-based lacquer sources.
The Complete Plantation Recordings are not as transparent, detailed, and dynamic as the 78rpm recording transfers to CD by Anatoly Markovich Likhnitsky, through the Audio Note (UK) Oto Phono Signature integrated amplifier, but they are still extremely good, and I think most listeners will be impressed by their musicality, fidelity, and quiet playback.
The Audio Note (UK) Oto Phono Signature integrated amplifier easily turned The Complete Plantation Recordings into an enjoyable musical experience, directly connecting me to this seminal music of Muddy Waters in fine fashion.
The overall tone of The Complete Plantation Recordings through the Audio Note (UK) Oto Phono Signature integrated amplifier was rich, naturally warm, with good dynamics and presence, making it easy to engage with the emotional content of the music and get lost in the music playing.
Sonically, audiophile-style recording artifacts like imaging, soundstage, resolution, and transparency don't apply quite as much to mono 78rpm transfers like The Complete Plantation Recordings, but what is on these records was presented realistically and enjoyably as the medium allows through the Audio Note (UK) Oto Phono Signature integrated amplifier.
If you're considering The Complete Plantation Recordings to revel in the imaging, soundstaging, and resolution of the recordings, you are barking up the wrong tree.
However, if you want to enjoy some historically important and superb music-making from 1941 - 1942, I think you will be delighted at what you hear, and through the Audio Note (UK) Oto Phono Signature integrated amplifier I immensely enjoyed every minute of my listening.
If you are a fan of Muddy Waters' music The Complete Plantation Recordings are a must have.
I thought it would also be fun to listen to Muddy Waters' Folk Singer, released as a 45rpm LP set by Analogue Productions, and widely praised by audiophiles around the world for its great music and sound quality.
Chad Kassem had Folk Singer remastered from the original 1963 Chess master tapes, and it is superb both musically and sonically through the Audio Note (UK) Oto Phono Signature integrated amplifier.
Muddy Waters plays acoustic guitar, is backed by Willie Dixon on a string bass, with Clifton James on drums, and Buddy Guy on acoustic guitar.
Muddy's vocals are center stage and are very expressive, possessing a full spectrum of dynamic shadings. Muddy's vocals are explosive at times, and a good test of a hifi's dynamic prowess. At live-like blues club levels, the Audio Note (UK) Oto Phono Signature integrated amplifier had power to spare even on Muddy's most explosive vocal dynamic peaks.
From a musicality perspective, Folk Singer sounds timbrally truthful, with superb dynamics across the spectrum, natural levels of resolution containing plenty of musical nuance, and with a vivid live-like presence of instruments and vocals.
Buddy Guy's guitar playing is superb, with lots of energy and an "in-person" level of resolution (ditto for Muddy). On the tracks he played on, Clifton James' drums provided a nice strong beat to drive the music along, and Willie Dixon's bass sounded natural, articulate, and excellent pitch definition courtesy of the Audio Note (UK) Oto Phono Signature integrated amplifier.
Through the Audio Note (UK) Oto Phono Signature integrated amplifier all of the audiophile-style elements were displayed superbly, with vivid imaging that possessed an abundance of "living" presence, and through the "Stokowski" Altec's the acoustic "sense of space" of the studio recording filled my listening room.
The Audio Note (UK) Oto Phono Signature integrated amplifier did an impressive job of making it sound like I had live musicians playing in my living room, with gorgeous natural tone, live-like dynamics, and provided me an intimate connection to the emotive content of the music.
In fact, I've never enjoyed Folk Singer as much as I did during my listening session with the Audio Note (UK) Oto Phono Signature integrated amplifier supplying the juice for the "Stokowski" Altec's—what a combination!
I just picked up a copy of the two-LP set of the Grammy Award winning jazz album Beyond the Missouri Sky by bassist Charlie Haden and guitarist Pat Metheny.
This minimalist duo album sounds absolutely gorgeous through the Audio Note (UK) Oto Phono Signature integrated amplifier. Metheny's playing is flawless on the guitar and a treat to hear, as is Haden's playing on the bass.
Haden's bass playing is articulate and tuneful, and there's no "one-note" bass here, as pitch definition is superb through the Audio Note (UK) Oto Phono Signature integrated amplifier.
One of the things I love about jazz is its rich tone color, which is all those tones that make up major 7th, minor 7th, dominant 7th, half-diminished, diminished, etc., chords that jazz musicians love to use.
Occasionally you'll see me refer to "tone color resolution", and by that, I mean a component's ability to clearly portray the unique tone colors of the music that give it its characteristic "feel". Can I clearly hear that flat seventh note that makes a dominant seventh chord sound like it is supposed to? Or that major seventh note that makes a major seventh chord sound like it is supposed to?
The Audio Note (UK) Oto Phono Signature integrated amplifier is very resolving, but not in a analytical way, but rather in a musical way, that gives full insight into important aspects of music like tone color, or timbral nuance, for example.
Beyond the Missouri Sky, was a superbly recorded album, but I should mention that the Oto has an uncanny ability to make all my albums sound like enjoyable music regardless of the quality of the recording.
Poorer recordings are still full of life and musical enlightenment, and really good recordings sound like "the voice of god" and are simply stunning.
This sort of ability to bring the best out in any music I want to listen to is a trait that I greatly admire in an audio component, and the Oto has it in spades.
For example, take Lucinda Williams' excellent album World Without Tears. Superb musicianship, outstanding lyrics, and somewhat edgy sound.
I saw Lucinda live in Seattle some months back, and she was superb. Lucinda benefited from her poet father's influence, Miller Williams, and she knows how to write artful lyrics.
At the concert Lucinda shared a lot about her life, and those lyrics are real-life experiences of hers, not made up fairy tales like a lot of songs. She's the real deal in her lyrics, in her life, and in her musical expression, and it comes across in spades in World Without Tears.
The Audio Note (UK) Oto Phono Signature integrated amplifier turns that edgy sounding World Without Tears album into a musical session of emotional impact that is harrowing, darkly beautiful, and a "real-life at the edge" experience to listen to.
You know me, I could go on and on about the Oto, describing what it does for the albums I love, but I think it's time to tie it off here.
Summary & Conclusions
The Manufacturer's Suggested Retail Price for the Oto Phono SE Signature is $6330 USD, which I think is a very fair price considering all of its features, its superbly hand-crafted nature, its uber quality of materials, and impressive musical and sonic performance.
I was telling Peter Qvortrup how well the Oto aligns with my own musical tastes, and Peter reminded me that the Oto is one of their "entry level" products, and their products' performance goes up commensurate with price.
Regardless of its position in the Audio Note (UK) product lines, the Oto Phono Signature integrated amplifier is one of the finest performing audio products I've ever had in my home at any price.
The Oto unfailingly delivers the music in an engaging fashion that I just can't seem to get enough of.
Whether I am listening to vinyl through the Oto's phono stage, or listening to digital through its line stages, the Oto never disappoints, and always delivers the maximum dosage of music to my soul.
If you want to find out why I went nuts over the Audio Note (UK) Oto Phono Signature integrated amplifier's performance, or why mastering engineer Steve Hoffman commented to me, "I use an Audio Note (UK) Oto Phono SE Signature in my studio. It's amazing, especially for the money, a really nice EL-84 unit that does it all." And "the Oto has everything I need in the studio, phono section, tape/EQ loop, everything." I suggest you give it a listen for yourself.
I think like Steve and myself, you too will be impressed by what you hear. Very, very, highly recommend to music lovers and audiophiles everywhere!
Oh, by the way, Peter sent me the Audio Note (UK) CD 2.1x/II Red Book CD player ($3874 USD) a short time ago to listen to.
The Audio Note (UK) CD 2.1x/II Red Book CD player is a natural pairing to the Oto Phono Signature integrated amplifier.
You will be reading more about this combination at Jeff's Place as I get more experience with the CD 2.1x/II Red Book CD player in my system, and of course in its future feature review at Positive Feedback.
Even at this early point in my listening the Audio Note (UK) CD 2.1x/II Red Book CD player is sounding superb, and I am immensely enjoying revisiting my large Red Book CD collection that I haven't listened to much over the last decade.
I would like to thank Peter Qvortrup for the opportunity to visit with him at his home and at Audio Note (UK), as well as for the opportunity to write about the Audio Note (UK) Oto Phono Signature integrated amplifier for you at Jeff's Place, and here at Positive Feedback.
I would also like to thank all of Peter's family and his Audio Note (UK) staff for their gracious hospitality towards me during my visit, you are all awesome!
As always, thanks for stopping by Positive Feedback to read my articles, dear readers, and may the tone be with you!
Audio Note (UK)
