unison research simply italy integrated...

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Ah 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 sub-stance to the external beauty or is it all just superficial vanity?

The equipmenTSimply 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 high-quality 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 (avail-able in a full timber finish or a combination

timber/aluminium finish) sports nicely-ma-chined 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 fully-motorised 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 but-tons 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-end-ed-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—impor-tantly because so much of a valve amplifier’s sonic ability depends, ultimately, on the quality of its output transformer.

Unison ReseaRch simply italy integRated

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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 even-lower 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 situa-tions create more problems than it can solve but 5dB could hardly be called excessive, and the Italian designers at Unison Research

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 hiSToryThe 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 ‘Sim-ply 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

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 well-established Simply Two, so it’s not surpris-ing the two amplifiers share many circuit topologies (both are single-ended ultra-linear 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 Re-search 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.)

performanceValve 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 mu-sicality to vocals as well as to the midrange in general. Yes, these qualities correspond to strengths associated with well-designed valve amplification—although not exclu-sively 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 audi-tioned 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 88dB-SPL), and both of whose impedances were not only fairly benign overall, but also did not drop below 5Ω at any point. Auditioned with these more-suitable loud-speakers, I found that the Simply Italy’s sonic ‘light’ shone very bright indeed.

Unison ReseaRch simply italy

Brand: Unison Researchmodel: Simply Italycategory: Integrated AmplifierRRp: $3,199Warranty: Two YearsDistributor: Radiance Audio Visualaddress: Unit 33. 5 Gladstone Street Castle Hill NSW 2154t: (02) 9659 1117e: [email protected]: www.radianceav.com.au

DesignSoundFit ‘n Finish

Needs reasonably efficient speakers

LAB REPORT: Turn to page 56Test results apply to review sample only.

Power Output: Single channel driven into 8-ohm and 4-ohm loads. [Unison Research Simply Italy]

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Power Output: Both channels driven into 8-ohm and 4-ohm loads. [Unison Research Simply Italy]

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On TEST Unison ReseaRch Simply iTaly inTEgraTEd amplifiEr

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Playing complex and dynamically chal-lenging 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 qual-ity 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 to-nality that immediately reveals the inherent nature of an instrument’s or vocal’s timbre.

The words ‘brightness’ or ‘brash-

ness’ will never be in the Simply Italy vernacular… and neither will the word ‘congested’ ever apply. This is one sweetly musical and engaging com-ponent. 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.

concluSionBe it with its impeccable build quality, its Italian design flair, or its superb sound qual-ity, 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. Highly recommended. Edgar Kramer

Power Output: Single and both channels driven into 8-ohm and 4-ohm loads. [SI]

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 BackgRoUnD

Delivers on its single-ended Class-A promise of ultimate musicality...

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laB rEpOrT Unison ReseaRch Simply iTaly inTEgraTEd amplifiEr

laboraTory TeST reSulTSMany experts claim that at least one of the reasons valve amplifiers sound so com-pletely 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 out-put 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 distor-tion 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 signifi-cant 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 com-ponent 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 dif-ference (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 Sim-ply Italy is being pushed hard, and you can see that the second-order harmonic is get-ting 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 con-siderable distance across the spectrogram. You can see that these outputs were meas-

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 cir-cuitry 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 har-monic 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 – test ResultsTest Measured Result Units/Comment

Frequency Response @ 1 watt o/p 7Hz – 90kHz –1dB

Frequency Response @ 1 watt o/p 6Hz – 105kHz –3dB

Channel Separation (dB) 40dB / 64dB / 47dB (20Hz / 1kHz / 20kHz)

Channel Balance 0.13 dB @ 1kHz

Interchannel Phase –4.3 / 0 / 0.59 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 dB referred to rated output

Input Sensitivity (CD Input) 50mV / 156mV (1-watt / rated output)

Output Impedance 1.5Ω OC = 2.9898V

Damping Factor 5.5 @1kHz

Power Consumption N/A / 112 watts (Standby / On)

Power Consumption 113 / 116 watts at 1-watt / at rated output

Mains Voltage Variation during Test 244 – 251 Minimum – Maximum

Unison Research simply italy amplifier – power outputChannel Load (Ω) 20Hz

(watts)20Hz

(dBW)1kHz

(watts)1kHz

(dBW)20kHz

(watts)20kHz (dBW)

1 8 Ω 4.5 6.5 9.2 9.6 4.5 4.5

2 8 Ω 4.5 6.5 8.8 9.4 4.5 4.5

1 4 Ω 3.6 5.5 6.2 7.9 3.6 3.6

2 4 Ω 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.

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Graph 2: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into a 4-ohmnon-inductive load, referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]

Newport Test Labs

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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]

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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]

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Graph 3: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohm non-inductive load, referenced to 0dB for both feedback settings. [Unison Research Simply Italy]

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Graph 6: Frequency response of line input at an output of 1-watt into an 8-ohm non-inductive 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.

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Graph 1: Total harmonic distortion (THD) at 1kHz at an output of 1-watt into an 8-ohmnon-inductive load, referenced to 0dB. [Unison Research Simply Italy Integrated Amplifier]

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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

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 feed-back 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 frequen-cies, 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

and 47dB at 20kHz, which is low but more than sufficient for proper channel separa-tion 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 set-tings, 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

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 aver-age 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,

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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 say-ing 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 imped-ance 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 dis-cover 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 lead-ing 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 band-width 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’ loudspeaker loads. Steve Holding

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