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Amp/Preamp Asylum: REVIEW: Audio Note OTO Phono SE Integrated Amplifier (Tube) by RGA

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REVIEW: Audio Note OTO Phono SE Integrated Amplifier (Tube)

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Model: OTO Phono SE
Category: Integrated Amplifier (Tube)
Suggested Retail Price: $3,100.00
Description: 10 watt Single Ended Pentode
Manufacturer URL: Audio Note
Manufacturer URL: Audio Note

Review by RGA ( A ) on July 17, 2005 at 13:19:14
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for the OTO Phono SE

Audio Note OTO PHONO SE (Class A - 10 Watts per channel into 4 or 8 ohms)

The Audio Note World:

There’s not a lot I can say about Audio Note that I have not already said over the years. I make no secrets of a heavy personal bias towards this company’s products and their reproduction of music which is, and has been, a revelation for me over the 15 years of listening to music and gear. Peter Qvortrup and his design team have managed to eliminate the separation of the music and the gear better than any other system I have heard and let the music, all kinds of music, simply be.

When I first came to this company they were unknown to me. The dealer I went to, Soundhounds in Victoria B.C. (www.soundhounds.com), which was also unknown to me, carried one of the more impressive selections of gear of any dealer I had come across over the years. I have grown up in the Solid State era and my first foray into tubes was with my Antique Sound labs MG Head DT Headphone Amplifier.

Reading, as I did, so many magazines and internet forums I had a pretty good idea that valves had lots of noise, distortion, and lacked power, resulting in, I was told, no real credible bass and no treble extension. They were also a pain to operate and expensive, or could be, to replace the tubes. My ASL is very quiet and I even ran it as a preamplifier so I began to wonder if the pundits were reading textbooks or if they actually bothered to listen. So it was quite a surprise to me to hear the AN E/SEC Silver loudspeakers being driven by a MASSIVE Silver amplifier with the Japanese name Meishu on the front, being fed by a big silver tube CD player that such internet blather could be so far from the truth as to drop my jaw.

At this time I did not know the system was tube based because the amplifier was covered and just looked like one of those big 300 watt Massive SS amps from Krell. What struck me was wow that is one smooth Solid State amplifier. Huge scale! Horns that really had a dynamic front to back sensation – when the horns come in you WILL pay them notice. The timing was extremely tight and nimble on anything with any kind of string. Indeed, what was striking to me most of all was the sheer nimbleness of the entire presentation. Open, fast, and with big scale but always remaining nimble on the subtleties of double bass, guitar etc. The timing was to a level that I had never heard to this degree before. And this timing from a big old “That’s Seventy Show” rectangular plain box with a goofball looking woofer with huge foam surrounds dwarfed by wood, lots of wood! Where’s the sub? I asked. There is none! So I thought, well it must have a 15 inch woofer in back then with all that wood after all it had more bass than the B&W N801 which has a 15 inch woofer so it made sense to me after all plenty of speaker have rear firing or side firing drivers. Visual inspected revealed no such third driver?

I set that curiosity aside and began to listen after all that’s what mattered. Piano and acoustic music is usually what I put on first simply to get a proper bearing. What struck me next was decay. Decay of a magnitude that was and is downright spooky. I am not surprised on subsequent visits that people, blocked off by a partition, peaked their head around and did a double to take to see where the musicians were and seeing none were in disbelief.

This was when I began asking about the amplifier because the system sounded so much better than I had heard that maybe it was the big power amp giving me this bass depth and organic sound to which it was revealed to me that it had a whole 8 watts on tap. It was what is called a Single Ended Triode. That’s right those funny little amps that get sneered at because the distortion is through the roof had no bass etc. Something was wrong then because indeed it was the BIG SS amps that sounded like they had no bass, and had an etched harsh quality to the treble (grainy). I don’t get it.

This was not what I was expecting, firstly this was powerful, full range, crystal clear to a goose-bump level, not distorted, could play loud… basically the experience had me doubting the drivel I had been reading for years on audio forums and in magazines. I didn’t get it. This completely mundane looking system perplexed me and my readings of the press which touted what was and is the virtual antithesis of this no name Audio Note set-up. I began to think maybe 30 wrongs make a right. Maybe the designers fluked, maybe it was the room, maybe there was a sealed subwoofer inside the E, maybe the salespeople send out happy gas to trick you? Or maybe it was something else. Maybe these guys were right.

This company had me doubting the press with their speaker boxes – square with no rounded edges? But slim boxes and treated front cabinets are better off axis have better clarity – but this speaker was far better vocally and the sound was more open. The speaker should be boxy sounding – but not so. Instruments had a visceral feel like thy do in life not the typical reproduced wall of banality and there was no grain. The drivers were too far apart so you should hear a significant step from drivers – again the reverse was true – The cohesiveness was utterly startling. The list of wrong things the speakers and amps and later the CD player were doing could not possibly be sounding this real.

The list of wrong things kept mounting up. Paper woofers, foam surrounds. I mean FOAM c’mon this was replaced decades ago for heaven sakes wasn't it? Just a two way! All things that immediately made me think “ they can’t be any good at all” Especially MIXING and cumulatively adding all of these totally obsolete wrong designs together – was I being tricked into liking these in some way? After all, SET is warm, bloomy, euphonic, overly sweet, and heavily veiled with copious amounts of distortion. After all everyone told me so.

The problem was that that simply was not what I was hearing. The sound was incredibly open, tight, and fast – warm and polite I heard from other British makers using SS gear interestingly enough. The leading edges were crisp and vibrant as I had heard from any of the other best designs I had heard. I heard no singer’s voice sound wobbly in loud crescendos and distortion should DISTORT the voice and any other instrument and it simply didn’t and does not happen.

No! Indeed, some of the speakers I have enjoyed have always been higher efficiency even some horn loaded, which were rarely described as warm. Discussing the mundane aspects of bass and treble seemed not to be relevant after that experience, because I was no longer focused on the bass or treble, Audio Note has no worries with their speakers on either end, what mattered to me is that everything sounded cohesive as one event in space, liquid, organic, fluid, and REAL

A Whole OTO Love!

The OTO Phono SE was the amplifier I had been listening to on virtually all my subsequent visits along with the Meishu. Listening to an amp like the accomplished underrated Rotel RA-2 switching to the OTO or Meishu really was a revelation. A stage appeared, the 2D wall fell away there was space front to back which was now realized and strangely a lack of noise (not added noise which SHOULD supposedly happen with tube amps. Silence was created in all its glory and I don’t know how to explain it, but there is something about silence which seems to add a level of contrast to the backdrop of reproduction that cannot and has not been there with my SS auditions…even my stint with the Bryston 3B ST, which has a phenomenal low noise floor, according the spec sheet, the envy of most in the industry. These Audio Notes were something different and special.

There is finish now to instruments and the background has not been lost. There is resolution. Piano works have all the extension, but now without that artificial pinging reverb that I thought was a plague on the CD format. No more of that edgy artificial grain or ringing which makes piano sound hard even strident and ultimately off-putting. Granted the Audio Note CD player will go a very long way here all by itself no doubt.
One of the reasons I gravitated to Sugden was that they seemed to smooth over some of the irritation and ultimately I would prefer an amp that veiled a little of the proceedings for one that sounded harsh.

The OTO gets rid of the Sugden veil without introducing the grain. It’s interesting that Sugden is one of the few SS makers that had the sense, in retrospect, to believe that SE and class A were, and are, worthy goals and that with all their attempts and leaps into class A/B the only amplifier in their line that has classic status is the A21a and it still remains musically superior to every other SS amplifier I have auditioned for anything around that price. Note the word musically – I have heard many that pyrotechnically best it. Personally, Pyrotechnics can be had cheaper in a big boom car if that’s your thing shop at Best Buy.

Reviewing the AN J/Spe was an ordeal because I wanted to avoid the usual list of praise one can find in every magazine about every speaker. The OTO Phono SE with its 10 watts per channel into either 4 or 8 ohms will seem to need a different approach. People who talk about Tube amps talk about organic sound, musical sound, and all the powdery feel good adjectives associated to tube amplifiers. Those who criticize tube amplifiers claim that we like it because it’s euphonic, not accurate (like they’d know). Lord knows music should never be Euphonic (pleasing or good). Heaven forbid music sounding good or pleasing on an audio reproduction system! Somewhere along the way everything has got all screwed up.

You Don’t Need to Win the LOTTO to Own the OTO.

Audio Note has some stupefying prices on some of their upscale equipment so it’s nice to see that they don’t forget the little guy. The OTO is by no means an inexpensive amplifier, but is in the reach of most audiophiles looking to get a real taste of the organic musicality of the single ended experience. A glorious combination of leading edge attack and full bodied decay with astonishing bass depth and grain free treble reproduction is the foray into the Audio Note world. It is interesting to note that this is amplifier to me sounds better than any solid state amplifier I have tried at any price. And just the entry level SE amp the company makes no less.

Bold words indeed! There is a caveat, however. One needs a good speaker match for the OTO. Audio Note designs systems not just isolated products. So matching the OTO to a 1 ohm 82db speaker is probably not going to yield even remotely good results. My comments are attributed to the amplifier matched up with Audio Note speakers or, likely, higher efficiency, flatter impedance speakers. Folks the OTO gets it oh so right and should be enough, with well matched speakers, to not have you return to Solid State amplification ever again. Something most SET lovers already claim. The vocal band is expressive and instrument overtones are presented with palpable realism.

Detailing the OTO

The OTO comes in a less costly push pull version and in a less costly Line only version, but basically the OTO PHONO SE is Audio Note’s entry level Single Ended Pentode amplifier(SEP). The amp has a tube PHONO stage for moving magnet cartridges. The amplifier is 140 mm high, 440mm wide and 410mm deep in a big black unassuming case. Five brass knobs on the front panel are for volume control, input selection (CD, Aux, PHONO and tuner), power on and off, source tape, and a balance control.
The amp uses 8 and 4 ohm taps with silver binding posts and connectors. The amplifier uses 10 tubes, 4 EL84, 3 ECC83, 2 ECC82, and 1 ECC88. Audio Note claims tubes should last roughly 8000 hours of use and performs best after an initial 200 hours of bedding in. They also recommend a 30-45 minute warm up period for each use for the amp for optimum performances. I have found that true but it sounds very good on initial (1 minute) start up as well. The amplifier, being class-A, gets very warm so good ventilation is required. (You can add an external power amp as well).

The amp is well packaged – double boxed in fact and comes with a photocopied 6 page manual with a staple in the top left corner. The amplifier has very impressive build quality with a metal body and thick front black gloss faceplate and the interior looks very nice. The amp comes with a 1 year warranty and 3 months on the tubes.


That is the question. And the question that follows is not whether this 10 watt amp will work well with your speakers, but whether your speakers will work with this amp.

From the Rock oomph of AC/DC and Aerosmith to Sarah Mclachlan’s or Kathleen Battle’s glorious sensual vocals to Beethoven’s full on 9th, the OTO is respectively a powerhouse of slam and a nimbly tuneful amp ready to take what you throw at it all in stride without a hint of gassing out. Chameleon like is the order of the day here. The price of entry into the Audio Note Single Ended world, for the rewards you will get from a set-up like this offers, it is a veritable steal. Audio Note is a company dedicated to music reproduction and while they may not look like much against some of the ritzy glitzy competition, they sound like bliss.

There are weaknesses to be careful of as stated below.

Product Weakness: 1) Runs hot so needs lots of space above the amplifier (no small racks)
2) No Remote Control
3) Sensitive to speaker matching (tough speakers may produce frequency extreme softening - not with my speakers however)
4) Not a lot of inputs
5) Needs warm up time to sound its best
6) Not the sexiest looking amp in this price range
7) Control labels underneath the knobs - a little difficult to see.
8) You very well may not want to listen to Solid State anymore.
Product Strengths: Music reproduction the lets the musical intent through. See review.

Associated Equipment for this Review:
Amplifier: Audio Note OTO Phono SE
Preamplifier (or None if Integrated): none
Sources (CDP/Turntable): NAD 533/Shure M97Xe cart (with Skylan Turntable Base). Cambridge Audio CD 6 and auditioned the Audio Note CD3.1
Speakers: Audio Note J/Spe corner positioned with matching filled stands
Cables/Interconnects: Yes
Music Used (Genre/Selections): Sarah Mclachlan, Sade, Loreena McKennit, Patricia Barber, Dianna Krall, Kathleen Battle, Renata Tebaldi, Maria Callas, Emma Shapplin, Gloria Estefan, Madonna, Linda Rondstadt, Dido, Allison Kraus and Union Station, Jewel, Ella Fitzgerald, Nina Simone, Judy Garland, Billie Holiday, Amanda Marshal, Shania Twain, Celine Dion, Lucinda Williams, Aimee Mann, Avril Lavigne, Cher, Whitney Houston, Jackson Browne, Phil Collins, Elton John, Don Henley, Tom Petty, King Crimson, Ray Charles, Chris Isaak, The White Stripes, Roxette, The Outfield, Delerium, Miles Davis, John Coltrane, Brian Blade, Donald Byrd, Motley Crue, Aerosmith, AC/DC, The Goo Goo Dolls, Spyro Gyra, Chet Baker, Lynard Skynard, Bob Seger, Tina Turner, Suzanne Vega, Billy Joel, Santana, Acoustic Alchemy, Leahy, Enya, David Sanborn, Norah Jones, Mike Oldfield, Jean Michale Jarre, The YellowJackets, Simply Red, Pet Shop Boys, Leonard Cohen, The Beatles, Classical music with all sorts of CDs and LPs from Ravel, Mozart, Albinoni, Corelli, Vivaldi (my favorite), Beethoven, Barber, Liszt, Dvorak, Chopin --- This was off the top of my head missing a great many no doubt.
Room Size (LxWxH): 15 x 12 x 8
Room Comments/Treatments: Acoustic panels on side walls and behind speakers on wall behind listening postion. The room is well damped with carpeting heavy drapes and room is filled with "stuff"
Time Period/Length of Audition: ~4 months
Type of Audition/Review: Product Owner

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Topic - REVIEW: Audio Note OTO Phono SE Integrated Amplifier (Tube) - RGA 13:19:14 07/17/05 ( 14)