The Unico 150 isn’t flawless, but it is immensely likeable. For some the size may be an issue, other may want a more transparent and precise performer, but we’re charmed by its big-hearted presentation.
What Hi-Fi?

The Unico 150 amplifier has been designed to suit both high-end audiophile and highly scientific criteria. This dual-approach to development has led to the creation of a product that is different to anything Unison Research – or any other manufacturer – have developed before: a powerful, great-sounding amplifier with only three stages (two tube stages and one power MOSFET stage).

  • 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: <0.4Ω, resistive on all audio frequencies
  • Power Consumption: 550 W (at max power on 8 ohm)
  • Dimensions: 43.5 cm x 18 cm x 44 cm
  • Net weight: 25 kg

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.

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.

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.

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 comboination 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 $6495 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 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.