Unico nuovo - Unison Research

Unico50
DualMono DualPower
Valve-BJTs
Integrated Amplifier
Not yet another Unico. Even if I can hear someone complain about “too many
Unico, so much that you cannot really call it Unico [only one, unique] any
more”. This can be true for a common piece of electronic but it can't be applied
to a high class product. This is why we're proud to introduce this new born
Unison Research amplifier.
Every new article entering the market (not only the Hi-Fi market) is presented
as a revolutionary novelty, every designer or manufacturer claims it's last
product to be the breaking point. Unico50 is a revolutionary breaking point in
the Unico series. And this is not rhetoric.
In designing the Unico50 the Unison Research technical staff has done
much more than designing a new amplifier. They set the starting point of a
completely new course.
Let's start from the more evident features and keep the best for later.
The Unico50 is a powerful stereo integrated amplifier fitted in a compact
chassis. Perfectly integrated in the last generation of higher level Unico line,
it matches the dimensions of UnicoCDE or UnicoPRE showing a well
proportioned looking and easy to integrate appeal.
Not scared by the challenge of combining aesthetic needs and technical
requirement, the design staff took the cumbersome oversized heatsinks and
turned them into a distinctive and representative trait of the Unico50: black
anodized custom designed side panels perfectly integrated in the whole
structure as a sign of strength and sturdiness.
The impression of concentrated power and reliability perceived at the first
glance will be confirmed at the first touch by the weight of the Unico50
(nearly the same of the Unico100) and by the feeling of the control interface

designed around a pair of solid aluminium knobs driving a couple of heavy duty
rotary encoders by ALPS especially selected for their high reliability and precise
and firm operation.
But a look inside the Unico50 won't be less satisfactory than the physical
contact, since it's in the circuit design that the breaking point has been set.
When removing the top cover a well engineered amplifier is disclosed to the
observer eyes but there's much more to know about the details of the design.
The input stage employs a refined version of the digitally controlled volume
control deigned firstly in Unico100; thanks to new integrated circuits the
allowed input signal swing is increased up to around 27V peak-to-peak and
fully protected from over voltage spikes. As in the previous design every input
is treated as a balanced signal preventing any possible ground loop and noise
generated by the cable connections.
The Unico50 is a hybrid amplifier, as per Unison Research tradition; the
tubes used are the well known ECC82/12AU7, pure class A biased, with
precisely regulated heater and high anodic voltage. But the in this new project
the preamp stage is an independent circuit working as a stand alone tube
preamplifier. There's no feedback from the power output to the input stage,
thus leading to a zero global feedback design! There's no feedback from the
output of the preamp stage even! The couple of triodes in the tube are
arranged respectively as a common cathode gain stage followed by a cathode
follower low impedance output stage.
The following driver stage derives directly from a well known and long time
tested topology designed by Unison Research. However, never tired of going
further, the technical staff refined the design in order to increase the inner
input impedance thus offering a better load to the preamp stage. In this
configuration the interface parameters are the same you can find when
matching a standalone preamplifier and a power amp.
Another revolutionary feature involves the power stage design: no more power
MOSFETs but power BJTs.
The bias control is the usual one, a proprietary design tested a refined with

years of experience, driving a couple of medium power MOSFETs in order to
offer the best input impedance to the driver stage ensuring high bandwidth
and great dynamic. These are followed by a couple of medium power BJTs
driving the power stage: four high current audio bipolar transistors arranged is
a mixed npn-pnp configuration.
The BJTs employed are especially designed for audio and exhibit high current
capability and great reliability; a thermally enhanced package in conjunction
with special thermal conductive insulation pads make them the perfect choice
for such a demanding design.
In order to reduce distortion introduced by inevitable dissymmetry of different
devices (even if measurement matched) we adopted a different approach
designing an uncommon topology that ensures perfect equality between the
positive and negative side of the power stage mixing npn and pnp devices.
Such a refined design can express its best only if supported by an adequate
power supply.
A no compromise design required a completely dual power layout; both left
and right channel are powered by they're own toroidal transformer (a 500VA
custom designed massive transformer) and an independent capacitors energy
storage of 40000uF placed as close as possible to the power devices.
As someone may notice in the Unico50 we use the same power transformers
and capacitors (respectively 1000VA and more than 80000uF) used in
Unico100. This ensures incredible current capability and thus fast, dynamic
and precise control of every loudspeaker.
Unico50 is a revolutionary breaking point in the Unico series.
A constructive revolution.
This new amplifier exhibits all the distinguishing features that leaded the
Unico series to the elite of the Hi-Fi devices but push the limit further
renewing the promise of an exciting listening experience.

Technical characteristics
Output power:
100W RMS on 8Ω
200W RMS on 4Ω
400W RMS on 2Ω
Pre stage:
Pure A Class
ECC82/12AU7
zero feedback
Power stage:
Dynamic A Class
POWER BJTs
Inputs:
4 line unbalanced
1 line balanced
Line Outputs:
1 tape
1 sub (volume controlled)
Outputs connectors:
4 + 4 for bi-wiring
Feedback factor:
zero
Power consumption:
1000W max
Dimensions:
17.1in x 5.1in x 17in
Net weight:
55lbs