Synthesis

Roma 96DC+ Integrated Amplifier

£2,649

The Synthesis Roma 96DC+ is an entry-level, Italian-made Class A tube integrated amplifier that uses four EL-34 output valves to deliver 25W per channel. While the + model has a built-in DAC, the basic Roma 96DC has no DAC but adds an extra line input. It's not available in all countries but is currently on sale in the UK for £2,649. In addition to two 350mV sensitivity analogue line inputs, the 96DC+ has a phono stage for moving magnet cartridges. Overall, the amp is simple and basic – just a volume control and input selector, both of which can be operated via an infrared remote.

Valve amps can be large and heavy, but this amplifier remains compact (260x415x200mm) and reasonably light at 18kg. Most of this weight comes from two large iron-silicon output transformers. Power consumption is around 200W max, which is about average for a 25W Class A amp. Its chassis is made from steel, but the front plate is solid brushed aluminium, some 20mm thick. The standard finish for the front panel is black, but there's also the option of a wooden front panel in a selection of exotic finishes available to order.

This amplifier takes thirty seconds to start up from cold and is relay-protected during this period. Optimal sound quality is reached after thirty minutes or so, says the manufacturer, which is the time needed for everything to attain full operating temperature. It does get fairly hot, but not excessively so. After an hour or so, case temperature above the transformers reaches the 42 degree centigrade mark, so do ensure adequate ventilation. Still, for a tube amp, it doesn't produce excessive amounts of heat. Indeed, all things considered – size, weight, heat – it's a very practical design.

With energy prices having risen considerably of late, the amount of power drawn by an amplifier is something many buyers may now wish to consider. Being full Class A, the Synthesis draws more power from the mains than a typical Class AB transistor amp with similar output power and way more than a Class D amplifier. Class A means full power is constantly being drawn, even when there's no music playing. So be aware of this when leaving the amp switched on and idling. Still, it's not excessive – there are amplifiers that drink much more juice!

The remote handset is mounted in a svelte brushed aluminium housing. Unfortunately, it needs to be pointed directly at the 96DC+ for it to work reliably. Having the receptor on the far right of the recessed front panel narrows its operating angle considerably. To ensure consistent operation, I ended up turning the amp about forty degrees anti-clockwise, so the front panel faced my listening seat directly. Without doing this, the remote wouldn't work. The motorised volume control operates smoothly and doesn't move too fast.

My partnering loudspeakers have an efficiency figure of 102dB, which is exceptionally high by normal market standards. I found myself listening with the volume mostly set at about 11 o'clock. The Roma proved very quiet in terms of hum and noise. Synthesis quotes a signal-to-noise ratio of -90dB, which is excellent. Physically, the amp is very quiet in operation, with no transformer buzz. You hear a few quiet 'clinks' from the tubes when you first switch on, but these stop after a few seconds and are perfectly normal.

THE LISTENING

Many audiophiles are attracted to tube amps because they believe (or hope!) such designs will give a smoother, richer, warmer sound when compared to a typical solid-state amp. But not all tube amps conform to this generalisation, as some can actually sound surprisingly forward and immediate. The Synthesis, however, does fit the tube stereotype – and has a beautifully sweet, mellifluous sound that's relaxed and warm without being soft or ill-focused. First impressions were of a velvety-smooth, 'liquid' sort of presentation that was effortlessly clean and detailed.

Compared to the Musical Fidelity Nu-Vista 800 that I'd been using beforehand, the Roma 96DC+ sounded noticeably richer and slightly less toppy. The MF amp had a tad more presence and bite, which gave the sound greater brilliance, whereas the latter was smoother and fuller. This difference was very noticeable on female vocals, as the amp's sweet presentation gave less emphasis to sibilants. During mixing and/or mastering, pop vocals are often given a bit of added 'presence' or brightness to make the voice project better, but this can lead to harshness. Not here, though.

Despite the Roma 96DC+ having a smoother, less immediate sound than my regular MF amp, it seemed every bit as good in terms of detail and clarity. The musical presentation was very solid and quietly focused. It doesn't scream detail at you, yet every musical line is rendered clearly. I noticed this early on while playing a recording of Josef Suk's Epilogue – this is a dark and rather densely-scored work for soloists, chorus, and orchestra. This amp was able to clarify passages that might have become clogged or muddy, yet did so while retaining a smooth, natural tonal balance.

Spinning West Side Story with The Oscar Peterson Trio on Verve, I was impressed by the incisive clarity, speed, and attack of the Roma 96DC+. There's some very fast 'machine-gun' like playing from Peterson and drummer Ed Thigpin, and the Synthesis reproduced this very crisply. It has a nice bass quality – quite full and round, but not lacking in speed or clarity. Overall, the presentation has a comfortable and alluring quality. It's clear and detailed, yet relaxed and easy to assimilate – like a pair of shoes that fit so perfectly you hardly know you're wearing them.

The rated output of 25W per channel is not massively powerful, but the Roma sounds gutsy and goes louder than its specifications suggest. It definitely punches above its weight. Increase the volume on dynamic material; it just gets louder without sounding compressed or congested. For example, I dug out an old (1983) jazz CD by the Warren Bernhardt Trio. It's on DMP – a record label launched at the start of the CD era to exploit the potential of silver disc. Some tracks like Four Part Improvisation offer explosive dynamics which really push your amp and speakers to their limits.

It sounded fine played with the volume control set around 11 o'clock, but really snapped into focus when I increased the level to 1 o'clock. It came over as very dynamic and clean, effortlessly stepping up an extra gear or two. Impressive stuff! While you'd be sensible to partner the amp with speakers having around 90dB (or more) sensitivity, the Roma gives the impression of having ample power reserves. It always sounds comfortable, and doesn't run out of steam unless pushed excessively hard.

The DAC has a USB input, plus coaxial (RCA) and optical inputs. It uses an Asahi Kasei AK4495SEQ chip with 32-bit resolution, usable up to 786kHz PCM, or 5.6MHz DSD. Windows users should go to www.synthesis.co.it and download a driver. Using coaxial or optical inputs, 24-bit resolution at a sampling rate of up to 192kHz is offered. Music played through the DAC from CD and USB sources sounded very good, though you need to increase volume levels by about 6dB compared to line sources.

The built-in MM phono stage proved excellent. It offers 40dB gain and is extremely quiet, with very low hiss and no hum. Of course, it would have been nice had MC sensitivity been included, but the lack of noise would make it perfectly usable with high output MC pickups. Having no MM cartridge to hand, I used a low output MC with a Music First Billington step-up transformer. The results were detailed and clean, though compared to my regular Sutherland PHD phono stage (which I use set to MM with the Billington transformer) the sound was a bit thinner. I couldn't fault the phono stage for clarity and focus, but the Sutherland/MF revealed extra depth and space that wasn't apparent using the Roma's phono stage. That said, the latter proved very enjoyable.

For me, the Roma 96DC+ is a tube amp having all the benefits of valves, but few of the drawbacks. In terms of sound, I liked its sheer unobtrusiveness very much. It's such a comfortable, transparent-sounding amplifier. It gives you the music without imparting its own spin on things. On CD it proved excellent, portraying a sense of depth and spaciousness. This would sometimes create three-dimensional holographic effects when least expected. Yet perhaps my overriding impression of the Roma 96DC+ was its discretion, as I generally hardly noticed it.

THE VERDICT

The Synthesis Roma 96DC+ never drew attention to itself and simply went about its job quietly and competently so that your attention was always focused on the music. As a result, it proved very easy – and rewarding – to listen to. If you've ever fancied the sonic benefits of tubes but were put off by things such as extreme heat and noise, excessive weight, large size, and so on, then do try it. Reasonably priced and well made, it offers everything you need and nothing you don't. What's not to like?

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