Unison Research Unico 150 Hybrid Integrated Amplifier Review
Unison Research Unico 150 Hybrid Integrated Amplifier Review website

Tubes and Solid State all in one package

Unison Research are an Italian HiFi manufacturer who have been making components for nearly 30 years and they are famous for their valve amplifiers. Over the years they have released my audiophile classic designs such as the Absolute 845.

The Unico range presents something a little different, it includes 3 CD players and a range of integrated, pre and power amplifiers. What makes the Unico integrated amplifier range unique is their hybrid design combining a tube based pre amplification stage with a solid state power amplification stage. Will this be an amplifier with all the benefits of both technologies with none of the drawbacks, I was very excited to find out.

I would like to thank Henley Audio and Richer Sounds Manchester for arranging and loaning me this sample for review

Unico 150 Unison Research most powerful amplifier

The Unico 150 with its 150 watts per channel @ 8 ohms is Unison Research most powerful amplifier and that is for good reason. Building an amplifier with higher power can mean adding more stages to the circuit to increase the gain. With the Unico range the amplifiers are either a 2 or 3 stage circuit, with the Unico 150 being the latter. The company have designed the amplifiers with as few stages as possible, a less is more philosophy. The first two circuit stages are valves used to give the amplifier its “character” with Unison Research choosing specific pure class A Tridoes based on certain key performance factors.

The dual mono, zero feedback solid state amplification stage is a class A/B design that can provide 220 watts per channel into a 4 ohm load. It is supported by two large torodial transformers that are capable of 400VA + 400VA continuously. Unison Research have chosen to use Mosfets in the Unico 150 that are capable of handling 1200w and 50amps so they are always working well under capacity.

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More good than just tubes in the preamplifier

The tube preamplification stage is a hightlight feature of the Unico 150 but its far from all that is good about it . It has an armoured ALPs Potentiometer, the inputs are connected only one at a time with armoured mechanical relays separating them and deflecting any potential RF noise other connected cables could introduce as potential antennae.

​For the balanced inputs transformers are used for a truly balanced transmission creating a theoretical infinite ground reference. Unison Research have chosen Mundorf capacitors for critical circuit positions, using them in parallel to reduce the effects of parasitic capacitance and to ensure low inductance. These design inclusions were made after vigorous listening tests to ensure the right performance, despite their extra cost.

Looks could split opinion

There is a lot going on under the hood of the Unico 150 with a lot of attentions to detail paid to it’s circuit design and power supplies. Lets not forget the asking price is only £4499 at the time of writing. I say only because we get a lot here for our money and I think in order to achieve that there has been a little bit sacrificed with the visual appeal of the amplifier.

It’s a nice looking amplifier and at 25kg its reasonably heavy but there are not any lavish touches to talk about. The volume and selector knobs have a unique interaction to them and I a little disappointed with the use of plain white LED’s for front indicators. Unison Research are far from alone in missing an opportunity to use the LED lighting to create nice visuals instead of just using a basic bright white light. Luxman and Musical Fidelity are good examples of LED’s done right. I am also a little disappointed with the top plate on the Unico 150, it feels too thin and will rattle with just a little tap.

There are plenty of connections on the rear including two balanced inputs and importantly a home cinema bypass. The connections used are of a good quality and feel very secure when you interact with them.

Sounds good very quickly

The Unico 150 has a short warm up cycle before you can use it, the left and right channel power indicator LED’s flash during this cycle. The manual states a 10 minute warm up period but in reality I think the Unico 150 sounds good straight away, it’s not an amplifier you will need to turn on an hour before you want to listen to it.

It does get fairly hot in use but thanks to the huge heat sinks and the well ventilated top the heat is limited to above the heat sinks rather than the whole amplifier becoming part of the heat sink as it does in a lot of cases. I would still suggest good ventilation as being important here.

Gutsy and Sweet

During my time with the Unico 150 its been working hard to win me over and for the most part it has and I can fully appreciate what Unison Research have created here. This is an amplifier designed for audiophiles to really enjoy listening to their music and enjoy their whole music collection. The amplifier remains totally composed for the very most part, with big and dynamic swings being handled extremely well even at very loud volumes. It presents music with a nice combination of sweetness and smoothness and marries this with excellent insight and micro detail retrieval keeping things interesting.

Impossible to Dislike

Unison Research claim to have built many prototypes and conducted many hours of listening tests until things were just right and interestingly their hard work has resulted in a product you can easily listen to for hour upon hour. Music is presented with an organic tonal quality, some could call warm others would call musical with the later referring to a presentation that is engaging on an emotional level. I listened to all manner of music styles through the Unico 150 from Classical to Dr Dre, from Pink Floyd to Boz Scaggs and there is a consistency to how all these music styles are presented, all being very easy to listen to and quite often thrilling. The amplifier has very good timing with good soundstage width and depth. You can push the amplifier hard and it still refuses to “harden up” despite having a volume ceiling in our review system past which the clarity starts to reduce.

Achilles Heel – but that’s missing the point

If I was to put my critical hat on and dissect the presentation I could critique the Unico 150 for being a little heavy handed in its presentation and favouring an overall warm tonal presentation in favour of leading edge clarity and sound stage space. I do feel this criticism would be missing the point of the Unico 150, its not designed as an audio analysis tool but a music maker to put a smile on your face and keep it there. The smile will keep getting bigger the more time you spend listening, it makes the old fashioned act of pressing play on an album and letting it play through a joy and not a chore because it doesn’t punish music that’s not produced perfectly. It gives all music styles good drive and purpose and there is an abundant amount of energy and toe tapping rhythm.

The other Achilles heel with the Unico 150 is with its deep bass control and presence. For the majority of music this will go by without ever being noticed because the amplifier’s presentation doesn’t need a full bass to balance it. The Unico 150 does do big bass, I don’t want to mislead with my previous comment play a track like Biggy Smalls Nasty Girl from Greatest Hits The Notorious B.I.G. and its bass quality is just as sweet sounding as the gruff vocal.

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Going back, sometimes there is no going back

I have often suggested the best way to asses the performance of a hifi component is to remove it from the system and see how much you miss it. Going forwards is not always as obvious as going backwards which is always very obvious. I spent a lot of my review time with the Unico 150 unsure of how its performance was compared to using the Chord DAVE as a DAC and Preamplifier into the Luxman M700 Ultimate Power Amplifier. I thought there was a lot of similarities with the later pairing being better for overall transient clarity and sound stage space. I was only partially right and actually quite wrong at the same time.

At the end of the review I installed the Luxman M700U and set the DAVE back to DAC and preamplifier duties and listened to the same tracks I had been using to test the Unico 150. There was definitely a cleaner leading edge and more sound stage space but that is because there was something missing - music. The Chord DAVE and Luxman combo sounded lean, dry and analytical by comparison, dear I say it even mechanical. A few hours later when the Luxman had warmed up the gap closed a bit but there was still some missing from the presentation. This came as a real shock to me and I still cant believe it now.

I am in personal deliberation over this situation - audiophiles often say tubes don't measure good but they sound good, they say tubes have a distortion that's pleasing to the ear. In this situation and comparison am I preferring a "nice" distortion to the clean and accurate truth?

​Final Thoughts

I started the review full of hope that a Hybrid Integrated Amplifier could have all the positives of both tubes and solid state technologies without any of their drawbacks. Does the Unico 150 hit a home run and achieve this near impossible task, not quite but it does make a very good justification for the hybrid amplifier because there is definitely something in it.

More importantly it has exceeded my expectations for an integrated amplifier at this price point. The Unico 150's qualities were very obvious to me during the review period but it's overall quality wasn't made apparent until I took it out and realised how much I missed it. A musical presentation that is full of life, energy and most impressively soul.

Spending time with the Unico 150 and enjoying its many performance strengths justifies audiophiles decisions to use a tube preamplifer with solid state amplification in separates form. The combination works at creating a very engaging, lively, sweet and easy to listen to musical experience that can hold your attention and keep you in the listening seat for many hours without fatigue or worse boredom.

The Unico 150 strikes a nice balance, it makes you aware of a recordings strengths and weaknesses without ever punishing them to the point of being un-listenable, even at loud volumes.

The big thing here is the price, the Unico 150 is £4499 at the time of writing and I think presents fantastic value for money for what it delivers. I would prefer a few changes to the visuals and construction and would happily pay a few hundred pounds premium for them but in reality these are far from deal breakers. Its not a perfect amplifier but I do feel it could be pretty much most things to a lot of audiophiles who favour musical involvement.

The Unison Research Unico 150 deserves our Special Performer Award, it has impressed me no end and has me intrigued to explore the audio world of valves. If you are shopping at around this price level you should hear it for yourself.

Special Performer Award Website Background

A Special Performer Award is Pursuit Perfect Systems highest accolade and is in recognition of exceptional product performance regardless of price