unison research simply italy integrated amplifier - Ultra High

on test
Unison Research
Simply Italy
Integrated
Amplifier
A
h yes, the Latin flair. Be it cars,
clothes, furniture or hi-fi, the
Italians can certainly slap together
some gorgeous designs. Take a look at
Simply Italy, a diminutive new integrated
amplifier from Unison Research, and you’ll
marvel at the exquisite aesthetics blended
with simple functionality. But is there substance to the external beauty or is it all just
superficial vanity?
The Equipment
Simply may be in its name but this little
Unison Research integrated amplifier has all
you’ll need for it to be the heart of a highquality stereo hi-fi system. For starters, the
quality of all the materials used is first rate,
and the quality of the assembly is also first
rate. The smoothly-rounded fascia (available in a full timber finish or a combination
52
timber/aluminium finish) sports nicely-machined knobs—featuring adorning circular
wood inserts—for input selection (on the
left of the faceplate) and for volume control
(on the right of the faceplate). The volume
control knob is the visible end of a fullymotorised potentiometer made by Alps. A
simple on/off toggle switch (again with an
attractive circular wood insert) is located
dead centre of the faceplate while a small
window located immediately below it serves
to receive commands from the supplied
infra-red remote control.
While we’re on the subject of remote
controls, the Simply Italy features a very
comprehensive unit—which obviously can
serve to operate other of Unison Research’s
components—with all-too-similar small buttons and gorgeously finished in timber and
aluminium.
The rear panel houses the RCA inputs
and outputs (three line inputs, one Tape in
and a Tape out), insulated speaker posts
and a fused IEC 240V mains socket.
The Simply Italy’s valve amplification is
based on a Class-A ultra-linear single-ended-triode circuit using a pair of the classic
EL34 output valves (unusually since they’re
pentode designs) to provide a claimed
12-watts ‘approximately’ power output per
channel while the input stage uses a 12AU7
per channel. A chrome-plated cage prevents
curious little fingers from being scalded, but
as far as I’m concerned, the Simply Italy is
far prettier without it.
Importantly, Unison Research claims to
build its own output transformers—importantly because so much of a valve amplifier’s
sonic ability depends, ultimately, on the
quality of its output transformer.
Newport Test Labs
The Simply Italy’s input impedance is 37kΩ,
making its source compatibility just about
universal, while its output impedance is
rated at 6Ω,
which offers reasonably wide speaker
suitability (though best results will still be
gained in situations where the connected
speakers’ impedance does not dip too low
and their efficiency is reasonably high).
Further speaker matching can be
achieved via the Simply Italy’s feedback
adjustability. Negative feedback can be
switched between a low 5dB to an evenlower 1.8dB. Unison Research says that the
higher feedback setting will subtly extend
the frequency response, particularly in the
bass. Excessive feedback can in some situations create more problems than it can solve
but 5dB could hardly be called excessive,
and the Italian designers at Unison Research
Power Output: Single channel driven into 8-ohm
and 4-ohm loads. [Unison Research Simply Italy]
Newport Test Labs
On TEST
Power Output: Both channels driven into 8-ohm
and 4-ohm loads. [Unison Research Simply Italy]
by the pope and a variety of monarchs, as
well as Austria, which ruled the regions of
Lombardy and Venetia.) Rather than start
the design from scratch, Unison Research’s
designers based the Simply Italy on the wellestablished Simply Two, so it’s not surprising the two amplifiers share many circuit
topologies (both are single-ended ultralinear Class-A designs, and both use EL34
valves in the output stage and ECC82 valves
in the preamp and driver stages. However,
whereas the Simply Two is a true dual mono
design, the Simply Italy is what Unison Research calls a ‘Quasi-Dual-Mono’, where the
power transformer and first filter stage the
power supply are doubled to separate the
preamp stages. (The Simply Two also has an
8Ω output tap, whereas that on the Simply
Italy is a 6Ω tap.)
Performance
have tailoring the feedback system in such a
way that it can reap real rewards within the
context of some systems.
With nothing in our photograph to
indicate scale, you may be surprised when
you see a Simply Italy ‘in the flesh’ so to
speak, because it’s not as big as you might
imagine a valve amplifier to be, measuring
just 260×350cm×190mm. It weighs 15kg.
Simply Italy History
The Simply Italy came about by virtue of
Unison Research wishing to release a new,
small integrated valve amplifier to celebrate
the 150th anniversary of Italian unification
on 17 March, 2011… hence the name ‘Simply Italy’. (If you’re not familiar with Italian
history, you might not know that prior to
1861, what we now call ‘Italy’ was simply
a grouping of city-states and regions ruled
Valve amplification is, sometimes justifiably
but most often wrongly, associated with a
sweet and syrupy sound compounded by
ill-defined bass. In the case of the Simply
Italy, I found that both statements were far
from accurate, although there is an element
of truth within…
Certainly my listening impressions were
that the Simply Italy presents a beautifully
detailed and resolute midrange… but I also
heard a good dollop of sweetness and musicality to vocals as well as to the midrange
in general. Yes, these qualities correspond
to strengths associated with well-designed
valve amplification—although not exclusively so.
I thought that in the low bass the little
12-watter did struggle somewhat when it
came to absolute control and bass power,
but then my reference speakers are notori-
ously difficult to drive and also cost more
than ten times the price Unison Research is
asking for its Simply Italy, so they’d be an
unlikely match on many counts. Cognisant
of this, I also auditioned the Simply
Italy with two other
pairs of speakers that
I deemed far more
sensible matches,
both having relatively
high efficiency (both
had been measured
as having sensitivity
of more than 88dBSPL), and both of
whose impedances
were not only fairly
benign overall, but
also did not drop
below 5Ω at any
point. Auditioned
with these moresuitable loudspeakers, I found
that the Simply
Italy’s sonic
‘light’ shone
very bright
indeed.
Unison Research
Simply Italy
Brand: Unison Research
Model: Simply Italy
Category: Integrated Amplifier
RRP: $3,199
Warranty: Two Years
Distributor: Radiance Audio Visual
Address: Unit 33. 5 Gladstone Street
Castle Hill NSW 2154
T: (02) 9659 1117
E: [email protected]
W: www.radianceav.com.au
Design
Sound
Fit ‘n Finish
Needs reasonably efficient
speakers
LAB REPORT: Turn to page 56
Test results apply to review sample only.
53
ON TEST
Unison Research Simply Italy Integrated Amplifier
Conclusion
Be it with its impeccable build quality, its
Italian design flair, or its superb sound quality, Unison Research’s Simply Italy will not
fail to impress. It delivers on its single-ended
Class-A promise of accurate tonality and
ultimate musicality whilst at the same time
surprising with excellent dynamics, exacting
resolution and generous bass registers.
Edgar Kramer
Highly recommended.
Unison Research Background
Power Output: Single and both channels
driven into 8-ohm and 4-ohm loads. [SI]
Playing complex and dynamically challenging material did not perturb the musical
proceedings one bit; no recording was too
dense for this amplifier. The Simply Italy just
opened up and resolved absolutely every
musical genre I could throw at it, so I don’t
have to qualify my praise for its sound quality with such phrases as “this is a great amp
for rock” or “suitable only for orchestral”.
No, I found that Unison Research’s Simply
Italy was equally adept at presenting music
no matter what its genre… and it did so
with seemingly-effortless sound in terms
of detail, separation, and perceived power.
There’s a sense of ‘rightness’ in terms of tonality that immediately reveals the inherent
nature of an instrument’s or vocal’s timbre.
The words ‘brightness’ or ‘brash-
Delivers on its
single-ended
Class-A
promise of
ultimate
musicality...
ness’ will never be in the Simply
Italy vernacular… and neither
will the word ‘congested’
ever apply. This is one sweetly
musical and engaging component. And with appropriate
speakers the little 12-watter
sounds big and bold, with large
dynamic contrasts throughout
the frequency range and a very
satisfying bass register in terms
of depth, pace and power.
54
Unison Research was founded in
1987 by a small group of audiophile
enthusiasts led by Giovanni Maria
Sacchetti. Sacchetti had begun
experimenting with valve amplifiers
as a child (he was born in 1945, prior
to the advent of transistors!) and
after completing a degree course
in electronics he dedicated himself
to teaching for 25 years, whilst at the
same time developing and designing
all the products for Unison Research.
Among the first products to wear
the Unison Research badge were
the ‘Glowy’, a preamplifier using five
twin-triodes in an all-valve circuit,
and the solid-state ‘Ruler’ amplifier.
These were followed by the ‘Nibly’,
an all-valve power amplifier that
used KT88s in push-pull which was
switchable between triode and
pentode operation. Unison Research’s
first integrated amplifier was the
Triode 20, which used two pairs of
push-pull EL34s in Class-AB. Its second
integrated was the Simply Two
which became a best-seller for the
company, selling more than 10,000
units within the space of four years
and opening up important Asian
export markets including Japan. In
1998, in order to give new impetus
and direction to Unison Research, a
change in the company structure
took place with A.R.I.A. (Advanced
Research In Audio Srl) being formed
to act as a parent company for
the Unison Research brand. Three
new partners joined the new
board, but the new product design
and overall direction of company
remained in the hands of Sacchetti.
In 2000 Giovanni Nasta became
the Managing Director of Unison
Research and appointed Professor
Leopoldo Rossetto, a lecturer at the
prestigious University of Padua, to
help Sachetti design a new range
of hybrid valve/solid-state amplifiers,
of which the ‘Unico’ series is now the
best-known. A.R.I.A., which is located
around 30km north of Venice, also
owns Opera, the famous Italian
loudspeaker manufacturer.
Unison Research Simply Italy Integrated Amplifier
LAB REPORT
Laboratory Test Results
Many experts claim that at least one of the
reasons valve amplifiers sound so completely different from solid-state amplifiers
is because valve amplifiers add high-level,
low-order distortion to the signals passing
through them. True or not, it was certainly
the case that the Unison Research Simply
Italy added such distortions to the signals
used to test it. Look at Graph 1, which
shows the output of the amplifier at an output of 1-watt into an 8Ω test load and you
can see at the far left the actual 1kHz test
signal, which reaches up and touches the
top of the graph, at 0dB. Immediately to
the right is a second-order harmonic distortion component (at 2kHz) that’s just 43dB
down, equivalent to 0.707% THD. Further
to the right is a third-order component at
–61dB (0.089%). These are the only significant components, because although fourth,
fifth and sixth-order components are visible
on the graph, they’re all around 90dB or
more below the 1kHz signal and thus would
be completely inaudible. To the left of the
1kHz test signal you can see the noise floor
is up around –70dB, but across most of the
audio band you can see that noise is more
than 100dB down. Tested into a 4Ω load
(Graph 2) you can see that output distortion
increased, with the second-order component coming in at –38dB (1.25%), the
third-order at –55dB (0.177%), fourth and
fifth-order at –78dB (0.012%) with 6th, 7th
and 8th-order components visible, but all
more than 90dB down (0.003%) and thus
inaudible.
As noted in the main review, it’s possible
to adjust the feedback levels of the Unison
Research Simply Italy, so Graph 3 shows the
effect of the two feedback settings on THD.
As you can see, there’s almost no real difference (though this is not true of its effect
on frequency response, as you’ll read in a
moment).
Graphs 4 and 5 show the distortion in
the output when the Unison Research Simply Italy is being pushed hard, and you can
see that the second-order harmonic is getting up towards being only 30dB below the
fundamental, which represents a distortion
level of around 3.16%. The second-order
component is around –43dB (0.707%) and
the third around –60dB (0.1%). In both
cases higher-order harmonics stretch a considerable distance across the spectrogram.
You can see that these outputs were meas-
56
ured at a level of 8-watts (into the 8Ω load)
and 6-watts (into the 4Ω load). Since the
Unison Research Simply Italy’s output circuitry is optimised for 6Ω loads this means
a slight mismatch in both cases, but since
only one or two speakers available in the
world will represent a true 6Ω load, the test
is valid. Despite the fairly high levels of harmonic distortion visible in the spectrograms,
the overall THD+N results for the Unison
Research Simply Italy were quite low at an
output level of one-watt, with Newport Test
Labs measuring just 0.7% THD+N. Referred
to an output of 12-watts per channel, the
distortion increased to 2.1% THD+N.
The frequency response of the Unison
Research Simply Italy across the audio band
(and beyond) is shown in Graph 6.
Unison Research Simply Italy Amplifier – Power Output
Channel
Load (Ω)
20Hz
(watts)
20Hz
(dBW)
1kHz
(watts)
1kHz
(dBW)
20kHz
(watts)
20kHz
(dBW)
1
8Ω
4.5
6.5
9.2
9.6
4.5
4.5
2
8Ω
4.5
6.5
8.8
9.4
4.5
4.5
1
4Ω
3.6
5.5
6.2
7.9
3.6
3.6
2
4Ω
3.6
5.5
6.0
7.7
3.6
3.6
Note: Figures in the dBW column represent output level in decibels referred to one watt output.
Unison Research Simply Italy Amplifier – Test Results
Test
Frequency Response @ 1 watt o/p
Frequency Response @ 1 watt o/p
Channel Separation (dB)
Channel Balance
Interchannel Phase
Measured Result
7Hz – 90kHz
6Hz – 105kHz
40dB / 64dB / 47dB
0.13
–4.3 / 0 / 0.59
Units/Comment
–1dB
–3dB
(20Hz / 1kHz / 20kHz)
dB @ 1kHz
degrees ( 20Hz / 1kHz / 20kHz)
THD+N
0.7% / 2.1%
@ 1-watt / @ rated output
Signal-to-Noise (unwghted/wghted)
62dB / 75dB
dB referred to 1-watt output
Signal-to-Noise (unwghted/wghted)
68dB / 81dB
Input Sensitivity (CD Input)
Output Impedance
Damping Factor
Power Consumption
50mV / 156mV
1.5Ω
5.5
N/A / 112
dB referred to rated output
(1-watt / rated output)
OC = 2.9898V
@1kHz
watts (Standby / On)
Power Consumption
113 / 116
watts at 1-watt / at rated output
Mains Voltage Variation during Test
244 – 251
Minimum – Maximum
on test
As you can see, there are four traces on the
graph. The black and red traces show the
Simply Italy’s performance when driving a
standard 8Ω non-inductive laboratory load,
for the two different settings of the feedback control (1.8dB and 5.0dB). You can
see that if you choose the lower of the two
settings, you’ll get around 0.5dB of extra
‘boost’ in the response at very low frequencies, but that otherwise the traces virtually
overlay each other. The blue and green
traces show the frequency response of
the Unison Research Simply Italy when it’s
driving a simulated loudspeaker load, again
for both settings of the feedback control.
You can see that whereas the frequency
responses into a non-inductive load are very
flat (essentially 20Hz to 20kHz ±0.25dB),
those into the simulated loudspeaker load
are not nearly so, varying by ±0.75dB over
the audio band. Although not quite so flat,
this is still an excellent frequency response,
with the differences undetectable by the
human ear. Further testing (the results of
which are shown in the tabulated chart)
showed that the Simply Italy’s frequency
response extended from 7Hz to 90kHz –1dB
and from 6Hz to 105kHz –3dB. This puts
the ‘normalised’ frequency response at 7Hz
to 90kHz ±0.5dB, which is an excellent
result. Channel separation was measured at
64dB at 1kHz, but dropped below 50dB at
the frequency extremes, to be 40dB at 20Hz
dBFS
0.00
Newport Test Labs
and 47dB at 20kHz, which is low but more
than sufficient for proper channel separation and stereo imaging.
Graph 7 shows that it will be almost
impossible to detect the effect of the two
different levels of feedback on the audio
signal by means of simplistic listening tests
using just a single amplifier and switching
back and forth between the two settings, because switching from one level
to the other results in difference in output
volume of 1.7dB. This difference in levels
is significant enough to ‘swamp’ all other
more subtle effects caused by feedback
level differences because when presented
with two similar signals, the human ear
will always perceive the louder of the two
as sounding superior to the one that’s not
as loud. This means that in the case of the
Simply Italy, the high feedback position will
always sound ‘better’ than the low setting
simply by virtue of it being louder. It’s true
dBFS
0.00
Newport Test Labs
-20.00
-40.00
-60.00
-80.00
-100.00
-120.00
-140.00
0.00 Hz
4000.00
8000.00
12000.00
16000.00
20000.00
Graph 1: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm
non-inductive load, referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]
dBFS
0.00
Newport Test Labs
that the result would also be influenced by
the additional bass boost that’s inherent in
the low-feedback position, but I think the
overall lift in volume will still swamp the
effects of the additional bass boost for most
program material. (Though I’d be the first
to admit that the difference might not be so
clear-cut if particularly bass-heavy musical
selections were used for the comparison.)
Signal-to-noise ratios were about average for a valve amplifier, with the Unison
Research Simply Italy returning figures of
62dB unweighted and 75dB A-weighted
referred to an output of one-watt, and
68dB unweighted and 81dB A-weighted
referred to an output of 12-watts. One
factor affecting these tests is that Newport
Test Labs reported that the Simply Italy was
a particularly microphonic valve amplifier,
meaning that any noise in the room at the
time of testing would affect the result.
The fact that it’s difficult to measure
the power output of a valve amplifier is
reflected in Unison Research’s own power
output claim for the Simply Italy, namely
that its output is “approximately 12-watts
per channel.” You should note also that
this output was measured into the 6Ω load
recommended by Unison Research, whereas
when Newport Test Labs measured the
Simply Italy’s power output, it did so into
8Ω and 6Ω loads. As measured by Newport
Test Labs, into these ‘unapproved’ loads,
dBFS
0.00
-20.00
-20.00
-20.00
-40.00
-40.00
-40.00
-60.00
-60.00
-60.00
-80.00
-80.00
-80.00
-100.00
-100.00
-100.00
-120.00
-120.00
-120.00
-140.00
-140.00
0.00 Hz
4000.00
Lab Report
Unison Research Simply Italy Integrated Amplifier
8000.00
12000.00
16000.00
20000.00
dBFS
0.00
-140.00
0.00 Hz
Graph 2: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into a 4-ohm
non-inductive load, referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]
4000.00
8000.00
12000.00
16000.00
20000.00
0.00 Hz
Graph 3: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm noninductive load, referenced to 0dB for both feedback settings. [Unison Research Simply Italy]
Newport Test Labs
-20.00
-40.00
Newport Test Labs
dBr
3.00
4000.00
8000.00
12000.00
16000.00
20000.00
Graph 4: Total harmonic distortion (THD) at 1kHz at 8-watts into an 8-ohm non-inductive load,
referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]
Newport Test Labs
dBr
3.00
2.00
2.00
1.00
1.00
0.00
0.00
-1.00
-1.00
-2.00
-2.00
Newport Test Labs
-60.00
-80.00
-100.00
-120.00
-3.00
-3.00
10.00 Hz
-140.00
0.00 Hz
4000.00
8000.00
12000.00
16000.00
Graph 5: Total harmonic distortion (THD) at 1kHz at 6-watts into a 4-ohm non-inductive load,
referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]
58
20000.00
100.00
1000.00
10000.00
Graph 6: Frequency response of line input at an output of 1-watt into an 8-ohm noninductive load with high (black trace) and low (red trace) feedback settings and also into
a combination resistive/inductive/capacitive load representative of a typical two-way
loudspeaker system with high (blue trace) and low (green trace) feedback settings.
30000.00
10.00 Hz
100.00
1000.00
10000.00
30000.00
Graph 7: Frequency response of line input at an output of 1-watt output
into an 8-ohm non-inductive load for high feedback (upper trace) vs low
feedback (lower trace) showing gain. [Unison Research Simply Italy]
Unison Research Simply Italy Integrated Amplifier
the Simply Italy’s maximum output was just
shy of 10-watts, and this was when just a
single channel was driven into an 8Ω load.
Output at the frequency extremes dropped
to 4.5-watts per channel. Note, however,
that this was the amplifier’s maximum
undistorted output, with distortion being
viewed on an oscilloscope. If some visible
waveform distortion were allowed during
the measurement, power output figures
would have been higher than shown in
the tabulated figures. And looking at these
tabulated figures, I’d be comfortable in saying that the Simply Italy will deliver a power
output of at least 10-watts per channel in
a typical home hi-fi system. This is a low
power output, and means that you will
have to choose your speakers very carefully,
not only in terms of ensuring their impedance modulus is as close to possible to 6Ω
right across their bandwidth, but also that
their sensitivity is very high—preferably
90dBSPL or higher—even if you listen at
relatively low volume levels.
As with all valve amplifiers, the Unison
Research Simply Italy will consume quite a
bit of mains power from your 240V socket,
even when it’s idling, or switched on and
not playing music at all. However, it draws
only around 100-watts, or the same as a
couple of low-voltage halogen down-lights.
However, in the interests of extending the
life of the valves in the Simply Italy, I would
recommend always turning the amplifier
off whenever you are not using it. And,
when you do need to use it, you’ll discover that it warms up quite quickly, so
no real ‘pre-conditioning’ will be required
in order to obtain best sound.
The Unison Research Simply Italy’s
performance reproducing square waves
was very good for a valve amplifier. The
100Hz waveform shows the tilt I’d expect
given the amplifier’s low-frequency 3dB
down-point of 6Hz, and no evidence
of phase shift, but you can see there’s
some h.f. overshoot visible on the leading edge. This overshoot becomes more
obvious on the 1kHz waveform but apart
from this the rise-time of the square
wave is very quick and the top of the
wave is flat after the ringing. At 10kHz
the ringing extends right across the
waveform, as I’d expect, but the rise-time
is still very fast, indicative of the bandwidth I’d expect from an amplifier whose
frequency response extends beyond
100kHz. Tested into a highly reactive
load that simulates an electrostatic
speaker, the Simply Italy’s response was
essentially the same as when driving a
standard 8Ω non-inductive load, albeit
with a very slight increase in ringing,
so the amplifier will be unconditionally
stable, even with the most ‘difficult’
Steve Holding
loudspeaker loads.
59
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