Unison Research Unico 150 integrated by David Abramson

Unison unico150_1.jpg




The solid-state/tube hybrid Unison Research Unico 150 is the most challenging amplifier I’ve ever reviewed. I’m talking 
physically. I work out, eat right, follow celebrity Tiktok advice for the best collagen powder protein shake and all, but it’s damnably heavy; feels like 60 pounds! Talk about functional fitness. I hurt my back (mildly) every single time I moved it, even if I bent at the knees. And fitting it in my two-seater car for shipping?! Man. Don’t go there. My recommendation is once you find a spot for it, leave it there. Don’t be a hero.

My Unico 150 arrived silver-clad, and an interesting soft silver it was, like something Benjamin Moore would name ‘Soft Wolf Silver’ or ‘Clouds’ Lining.’ Sporting a Hexfet output stage, a couple of ECC83’s in the input stage, and a pair of 6H30 tubes in the driver stage, this big boy beef-eating hybrid tube/solid-state amp also comes in boss black. The new distributor Boris at JB Distributors informed me my Unico 150 was a brand-new unit and, as such, might require a bit of break-in.  Now despite what some corners of the YouTubes may say, 30 plus years of audio experience with all manner of gear (and more than 150 pairs of speakers and counting) has shown me that while the period of time varies widely (due to listening volume preferences, etc.), it’s a rare item that doesn’t benefit from at least some break-in period sonically and the Unico 150 was no exception. 







To go off on a bit of a rant here, it’s certainly not a ‘marketing trick’ or ‘your ears breaking in’ when say a speaker goes from sounding like it has zero bass and muted highs to having solid bass and extended highs, as was the case with my Xavian Perla Esclusiva monitors after 40 or 50 hours or with my B&W 606 S2 Anniversary’s (initially) rough highs and muddy bass. It’s just mechanical suspensions loosening a bit, as would be expected from repeated flexing of anything that hadn’t been flexed much (or at all) before. No voodoo. No magic. Just do biceps curls with your 30lb fitness band for a year, then tell me if it still measures exactly the same as when you got it from Bezos. With amps, it may be capacitors charging and discharging/things coming up to operating temperatures enough times, etc.  


So speaker and amp designers and purveyors like John Devore and Peter Qvortrup (Audio Note) aren’t all lying and recommending break-in so they can sell you crap! They know things change a bit sonically from new and, in some cases, drastically so. Such changes are, in fact, a known quantity that expert designers like Devore account for and work with when designing. (Email and ask him!) Rant over. Fortunately, the Unico 150 sounded pretty friggin’ good from the get-go but the highs did smooth out a bit, and detail became more apparent after maybe 100-150 hours of continuous play (I just streamed Tidal at low levels and left it on overnight for a few nights, re-listening each day). 



The (mighty) Sound and the (considerable) Fury



Let’s get something out of the way right off: this amplifier has a sound. Every time an amp comes in for review, I panic a little beforehand, thinking, ‘what if it sounds exactly same as any other amplifier?’ ‘What if I can’t tell the difference!?’ What if Julian Hirsch and Stereo Review magazine (and now ASR) were right all those years ago, and everything sounds exactly the same because it measures almost the same except for THD or some such thing?!! 


Well, with the Unico 150, such fears were unfounded. This tube hybrid is (drum roll) slightly, invitingly warm. That much was apparent from the offing (the ‘on’-ing?), and to boot, it doesn’t take long to warm up each day; maybe ten or fifteen minutes, and you’re off to the races. Of note, the Unico is much quicker to come on song than, say, a typical KT88 thermionic rival or my old Pass F6, which took like 30-40 minutes to get up to snuff. This matters in daily usage. Sometimes you wanna hear music NOW and not wait an hour for things to ‘gel.’ Mechanically, the hybrid Unico 150 gets pleasingly warm to the touch, but for egg frying, you’ll still have to grab your Costco Hexclad skillet.


Speaking of warmth, the Pass amps I’ve owned (F6 and Aleph 3) were similarly (to varying degrees) invitingly tonally warm. The Crofts, the Audio Art Diavolo, the Audio Note P2SE, the Bel Cantos, the… you get the picture. All mildly, beguilingly warm. And while they certainly all shared that single sonic characteristic, they didn’t (necessarily) share much else. So to my original hybrid 70-watt Unico (now aka Unico Primo), the one I owned when I first started reviewing for 6moons years ago, was invitingly warm, and I loved it! I used it for several years with a litany of speakers from the Proac Response 1.5’s to the Totem Arro to Devore Gibbon 8 and Harbeth Compact 7ES. In fact, of all the amps I’ve ever owned, I think my original Unico just may have been the most versatile and my favorite. Especially with speakers like my Proac 1.5’s and Audio Physic Virgos and later and especially with those Arros, it just had a way with music. Ballsy, involving, pacey, electrically quiet, and slightly warm tonally, I should never have sold it. We all know we only think warm n’ fuzzy nostalgic thoughts like that about gear we’ve sold off very occasionally. 


At the time, as I recall, Unico was on the rise in the amplification world, and that wave maybe crested in, say, the early to mid-2000s, and then, for several years, there wasn’t much Unico to be found. Apparently, Unison Research, the company, was bandied about between several distributors including at one point Cardas Audio, and then seems largely to have disappeared from view. Pity. Until that is, Boris of JB Distributors, who has some history of involvement with warranty repairs for the brand, picked up the Italian rugby ball and begun running with it. We should all be grateful for that! In my experience, Unison Research does not make any products that don’t make great music, and it’s a line that deserves, more than many of the sacred cows, to be given its due. 


Unico(rn) Rides

Franzmozart.jpg“This is the most authoritative and biggest I’ve ever heard the diminutive Dali Oberon 5’s appear. Watts is watts. Big watts grabs a speaker by the short and curlies and says, “you’re comin’ with me, punk!!” These were among the first listening notes I took during this review. During Kholodenko’s Tchaikovsky playing via Quobuz, I followed up with “super quiet…big macro dynamic punch…. superb image density and timing that keeps pace with my Naim XS 3 and Lejonklou Boazu…” “Spacious and airy,” I continued. Sometime in the first few days, I added, “there is a very slight and charming bit of warmth and mid-bass fullness with no loss of definition. You get big piano purrrr without tubey muddiness; just big-time heft and weight. Man, I sound impressed! And I was


With Andriy Dragan playing the Franz Xaver Mozart variations (such a great piano recording!) via Quobuz, there was again that bit of beguiling warmth wedded to mid-bass power and superb depth. You can see the piano in front of you out there on the stage. Close your eyes, and you really can imagine you’re at a concert where no one’s coughing or talking or playing with their phone; in other words, a concert on Richard Branson’s Necker island or in Fantasy Land (whichever one you’ve earned enough points to visit). Speaking of fantasia, on the second track, Fantasy on a Russian Folk Song, the way the 150 lets Dragan’s glimmering top notes light up the hall air and die into it is just beautiful. Notes are struck, melt into one another and die away into that thick hall ambiance in reasonable enough facsimile to life that suspension of disbelief occurs. Ah, we audiophiles live for such moments! 



All the rapid-fire ‘low down’ left-hand work in Variation on a theme of Don Giovani’ is starkly apparent with no muddying or obfuscation. In sum, for all the world, we very might have tickets to the Dragan concert this night and be their mid-hall with dinner plans after; our significant other leaning into us warmly mid-concert as we hold hands in the red velvet seats at Grand Hall in Any City, Anywhere. Hey – I know we’re not at the place and time where we have a virtually perfect copy of live music in the home, but with unamplified acoustic music at least, a truly great and powerful amp like the Unico 150 can at times get you really close perceptually to being there. That’s what the original Unico did for me years ago with a pair of Totem Arros and an Audio Note DAC 2.1 Signature in a smaller room; took me to the venue with a smaller-scale acoustic fare. 


Imagine a great Thai green curry dish. Now imagine a bit of extra coconut milk for creaminess. That’s what I get with the 150, a slightly richer broth than the Naim or the Chef’s signature Lejonklou stew. It’s a warmth like Audio Note (I’ve owned the P2SE amp and the 2.1 Signature DAC) and the Pass amps (I’ve had both the Aleph 3 and the F6). It’s a warmth that’s there- but it’s consonant and welcome, never cloying or overdone. Come to think of it, even with my Simaudio solid-state pre; the Pass F6 was a bit tonally warm for my tastes. The Unico is never any such thing. 


Ask anyone what they think of the Pass Labs integrated; they’ll tell you ‘slightly warm but fantastic tone’ At least, that’s what one of my favorite blogger’s camera guy Steve Huff of stevehuffphoto.com says about his, and the 150 is the same story. In fact, I’d love to hear the Pass Int 25 or 60 next to this Unico. I’ll just bet they’d be brothers from another mother, except, of course, the Unico 150 isn’t the runt of the litter!


jeffhamilton.jpgNow here is the Unico’s neat trick; zero blur or slowing. Catch me if you Can, the title track from the album of the same name featuring the Jeff Hamilton Trio, swings and bounces along as quickly as it does on my smaller speed-demon amps. Absolutely no sluggishness. Not even as compared with my memory of the PRaT of the original Unico (which was one of the reasons it so endeared itself to me). I’m tapping my feet and getting into the proceedings just the same as with my smaller integrateds, both of which are known far and wide across the ‘tune dem/flat earth’ interwebs for their way with musical timingAnd the cymbals on this album shimmer and sheen just as they do with the Boazu and the XS 3, indicating no significant truncation to my ear of high-end extension or detail. In sum, something added; a bit of thickening and warmth, but nothing lost. On track four, ‘The Pond,’ the pianist holds cords while the ensemble plays over then, and the overtones on the sustain from those cords go on and on, fading into the other instrumental lines and lighting up the air of the recording venue. Glorious. The sparse drum solo on bijou was about as live a drum sound as I’ve ever had in any of my home systems; powerful, punctuated, and precise. 


And the depth of field and sheer scale the 150 conjures here are notable. In fact, the scale the 150 can create is among the best I’ve ever heard. My fave 32″ high Oberons sound at times 64″ tall when the Unico powers them. Really it’s incongruous. And this scale is allied to certainly the most potent macro-dynamics I’ve heard from any of my amps. You can listen to well-recorded original instruments such as those collected together under the baton of violinist/conductor Julien Chauvin playing Haydn’s Symphony no. 84 (La Discrete) till your heart’s content without any hint of listener fatigue from bowed catgut. The 150 never tires you out. 


chole.jpgAnd I can’t forget the Unico’s gorgeous vocal portrayal; vocals like those on Chloe Foy’s Evangeline from her album “Where Shall we Begin” followed by excellent lateral staging throughout the next track, ‘Asylum.’ Switching to the 110-watts-less-powerful Lejonklou Boazu integrated with Chloe Foy immediately shaves away some of the pleasing tube warmth/mid-bass warmth and improves instrumental separation and overall clarity whilst of course doing that jet-black-background-at-night-developed-in-a-cloud-of-blackness thing the Lejonklou does. There is more apparent jangle to metal strings and tambourine. Voices and instruments at the edges of the soundscape are more separable and apparent. Boazu stages a bit wider as well. Buuuut… keep in mind Boazu is a 40-watt reindeer that majors on clarity and cleanliness.  

In short, the Boazu is a completely different artist and aesthetic; it is all clarity and purity and blackness and transparency, and the Unico is warmth and power and punch with perhaps a more projected midrange. (Of note, my Naim XS 3 sort of lands in between the two of them tonally). Boazu is an utterly open window, and Unico is a clean window with a light tint to keep the harmful rays of the sun out. Very welcome on a too-bright day! 



Requiem for a Heavyweight


In sum and lots of substance, the Unico 150 sounds exactly how you’d imagine a well-designed tube hybrid would; like a big powerful, sleek modern solid-state amp with a splash of classic tube warmth and color, but faster than a classic tube amp (and many a modern one) and less humid. 


Vinshine 250x250.jpgCriticisms? Ok; like my Naim XS 3, which also uses an Alps Blue Velvet volume pot, channel balance at very low volumes (below listening level with speakers of average sensitivity) is slightly skewed to one side, and I noticed a very slight transformer hum only audible with your ear a few inches above the unit. Impressive lack of self-noise actually for an amp of this size and power. Operationally there were zero glitches or issues over the few months I lived with it. Slightly warm, possessed of fantastic tone, massive punch, and scale, with depth and space for days, but managing to sound unfailingly pacey and involving, I found the Unico 150 to be just as pacey and musically engaging as my rather pacey and involving Naim and Lejonklou amps. Carrying all that weight around and still keeping up stride for stride with the fastest kids on the block? That’s no mean feat! 


In sum and (substantial) substance then, the heavyweight Unico 150 is largely the same as its little brother ever was; fantástico! But bigger and more potent. The 150 does little to dim my Unico fires of old. Unless maybe you’re got super warm-sounding speakers or a clinical accuracy uber alles fetish, I can’t imagine a music lover not musically loving this amp. Quiet, refined, powerful, dynamic, and tonally beautiful, the Unico 150 is easily among the very best and most versatile amplifiers I’ve ever had in my home.  

I bid you peace.


David Abramson  

Main System:


Source:  Lumin U1 mini streaming Tidal and Quobuz; Holo Audio KTE May DAC

Amplification:  Lejonklou Boazu integrated amplifier; Naim XS 3 integrated amplifier

Loudspeakers: Dali Oberon 5; Xavian Perla Esclusiva; Spendor 3/1 Classic 

Cables: Linn K20 and K400 speaker cable; Skywire Audio 1400SE interconnects; Mogami 3080 AES/EBU digital cable or Audioquest Carbon USB cable

Accessories: Symposium Acoustics Svelte Plus shelf; Symposium Acoustics Rollerblock Juniors (all utilized under the DAC)



Unico 150 Specifications:

Price: 6500.00

  • Output power:     150+150 W RMS at 8Ω / 220+220 W RMS at 4Ω
  • Frequency response: -1dB @ 12Hz & 45kHz, -3 dB @ 6Hz & 80 kHz
  • Input impedance:    24kΩ // 100pF
  • Input sensitivity:    860mV RMS
  • Input stage:     Pure A class, double triode totem pole ECC83
  • Driver stage    Pure A class, double triode totem pole 6H30
  • Output stage:     Class AB thermostable, complementary Hexfet (4 pairs for channel)
  • Input:    6 line (3 unbalanced, 2 balanced, 1 “bypass” unbalanced)
  • Line Outputs:    1 tape, 1 sub  (volume controlled)
  • Output connectors:    4 + 4  bi-wiring
  • Global Feedback factor:    0 dB
  • Local Feedback factor:    16 dB
  • THD:    < 0.15% @ 1kHz, 1 W
        < 0.25% @ 1kHz, 10 W
        < 0.35% @ 1kHz, 100 W
        < 0.9% da 20 a 20000 Hz, 150 W
  • Output resistance:    
  • Power Consumption:     550 W (at max power on 8 ohm)
  • Dimensions:    43.5 cm x 18 cm x 44 cm
  • Net weight:    25 kg

US distributor Website: jbd-usa.com


A.R.I.A. Advanced Research in Audio

via Barone, 4

31030 Dosson di Casier (Treviso)


Ph. +39 0422 633547

Fax +39 0422 633550




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