Synthesis Roma 117DC/Roma 98DC preamp/mono power amp combination

Certain audio technologies seem to appeal to some nationalities more than others and Italy is clearly in the valve camp. Synthesis has been making valve based audio components in Morrovalle, Macerata near the Adriatic coast since 1992, but that was not the beginning. Founder Luigi Lorenzon’s father ran a transformer business called FASEL which started in 1961 and specialised in electronics for guitar amplifiers including the Vox AC30 (as used by the Beatles) and the Cry Baby Wah-Wah pedal so beloved by one Jimi Hendrix. A good grounding in transformer design would have provided a great springboard for the fledgeling Synthesis brand in the early days, giving it an advantage over other companies during the valve amp revival of the early 1990s.

Today, Synthesis makes a broad range of amplifiers in both pure valve and hybrid forms as well as two CD players and a DAC. The Roma models are distinguished by wooden facias with a lacquered finish. But not necessarily in red, that just seems to be the company’s preferred colour. In fact, there are a variety of finishes to choose from including anodised aluminium rather than wood.

The Roma 117DC is a line stage preamplifier with both balanced and single ended inputs that runs two pairs of 6922/ECC88 double triode valves in order to offer gain should it be required. It has a transformer on the output in order to offer an impedance match with connected power amplifiers. This is not essential on a valve preamplifier, but if you are a transformer specialist like Synthesis it makes sense. The large volume control knob is attached to a motorised pot and can be controlled with a rather attractive aluminium remote handset, this will also change inputs and control functions on other Synthesis components. The circuit has been laid out with switching near the input sockets to keep signal paths short and minimise crosstalk, and precision components are used alongside valves selected for low noise and resistance to microphonics.

Window

The power switch is designed to confuse the unwary by virtue of the fact that when it’s illuminated the preamp is off, which is fine when you know what’s going on. Many years ago I had a DNM preamp with a similar peccadillo, I returned late one evening to find that my wife had nearly thrown it out the window because she couldn’t get it to work on account of the power being off when the light was on. The orange circle of light is attractive though and when you depress the button for a couple of seconds a relay clicks in and the circle flashes for 45 seconds whilst the preamp warms up, when the light is off the fun can begin.

The Roma 98DC monoblock power amplifier is a chunky device that runs a pair of KT88 output valves and is specified to deliver 80 Watts. Its hefty 16kg mass indicates the presence of some serious iron in the output transformer, which is made by Synthesis in house; it claims that it delivers a wide response with low distortion. As output transformers are the most critical element in a valve amplifier, a company with so much expertise in the field inspires confidence no end. You can upgrade valves all you like but the bottleneck is often the output transformer.

I like the VU meters on the front of these monoblocks; they are backlit and twitch in response to demand from the signal. They can also be used to set the bias for the tubes which Synthesis encourage you to have done by a professional but also helpfully give instructions on how to do it yourself. Rear inputs extend to XLR and RCA sockets with two sets of speaker cable terminals for ease of bi-wiring. Unusually for a valve amp there are not alternative positive terminals for different impedance loads, presumably the output transformers have sufficient capacity not to require this. The power button illumination quandary also applies here but at least you can see the meter’s glowing when it’s on.

We need valves in our lives

Once the slightly crude nature of the volume buttons on the remote had been mastered I had an awful lot of fun with these amplifiers, once again prompting the question: why don’t I have a valve amp in my life at all times? These ones have the ability to reveal the heart and soul of the music and make listening to it that much more involving and enjoyable. Is this because they have great timing, an emphasis on the midrange or harmonic distortions that are different to those of transistor designs? It’s hard to say but very easy to hear. The Synthesis Roma pre/mono amp trio delivers the vitality and flair in all manner of musical styles and manage to bring out the good stuff in recordings that often sound crude when reproduced by more up to date tech.

Abdullah Ibrahim’s piano can sound hard and clanky but here his musical fluency takes centre stage and pushes the still slightly hard tonality out of the way, it’s less edgy but also more coherent, which means the melodies take centre stage and the music becomes truly enchanting. Steely Dan’s ‘Babylon Sisters’ is a staple of my reviewing playlist and one which in truth does not usually inspire much enthusiasm, it was chosen because it’s good but not a favourite. You don’t want to overplay the greats. Yet on the Roma powered system it came alive and induced something that, in the privacy of one’s own listening room, passes for singing. The mute trumpet is superb, Bernard Purdie’s shuffle drums irresistible and the horn section truly radiant, these amps put the joy back in this track in no uncertain fashion.

Sublime and substantial

If you stand back and stop playing music for a few minutes it becomes clear that there is some background hiss with these amps, this is not unusual with valve technology and in this case substituting a passive preamplifier indicated that the Roma 117DC preamp is the source. That said, once the music is playing it becomes irrelevant, drop Ryan Adams and the Cardinals playing ‘Hallelujah’ live and you are immersed in a sublime and substantial soundstage that draws the listener in. The balance is clearly on the warm side by transistor standards but this could also be interpreted as the cooler running technology producing a colder sound. The Roma 98DC amps are Class AB devices, hence their relatively high power, so there is muscle on tap when it’s required and their balance is in no way soft or wafty. You probably don’t get the transparency of Class A valves but most examples can’t control anything but the most sensitive loudspeakers, and there aren’t too many of those that will fit in the average metropolitan living room.

These amps are not shy when it comes to revealing the full glory of the music, this was apparent with all sorts of music but made itself obvious with Terry Callier’s ‘Lazarus Man’ (Timepeace), here the emotional power of the performance is enhanced by the Synthesis amplifiers to produce a degree of humanity that’s rarely achieved with recorded music. Valves are not tonally neutral but they have different harmonic distortion characteristics to solid state devices, and these favour what is arguably the most important thing about music, its ability to communicate emotion, and this Synthesis trio is effortless in this regard. You don’t get silent backgrounds or bone crunching bass, you get shivers up your spine and a warmth that makes the listening experience so rewarding. You also get clean, sweet treble and a degree of transparency that is hard to replicate.

The Synthesis Roma components don’t go overboard on features but provide those that are necessary to do the job well, I for one would always prefer to have a separate DAC and phono stage as those onboard preamplifiers are usually compromised when it comes to power supply. The quality of transformer shines through in both preamp and power amps, the latter providing sufficient grip but always putting musical flow at the fore. But if you really want to know why they work, put on a great piece of music and try not to react physically or emotionally. An engineer might be able to do it but not a true music lover.

Technical specifications

Synthesis Roma 117DC

• Type Valve-driven line-stage preamplifier with headphone output
• Valve complement Four 6922/6DJ8/ECC88
• Analogue inputs One pair of balanced inputs (via XLR connectors), four single-ended inputs (via RCA jacks)
• Analogue outputs One pair of balanced outputs (via XLR connectors), two pairs of single-ended outputs (via RCA jacks), one pair of single-ended tape outputs (via RCA jacks)
• Input impedance 100 kOhms (via XLR connectors), 47kΩ unbalanced (via RCA jacks)
• Output impedance 1kΩ balanced (via XLR connectors), 500Ω (via RCA jacks)
• Bandwidth Not specified
• Gain + 22.5 dB (via XLR connectors), + 16.5 dB (via RCA jacks)
• Distortion < 0.1% (20 Hz–20 kHz) 1VRMS
• Signal to Noise Ratio > 90 dB (Weighted A)
• Dimensions (H×W×D) 167 × 480 × 450mm
• Weight 10kg
• Price £4,249

Synthesis Roma 98DC

• Type Valve-driven monoblock power amplifier
• Valve complement Two KT88, one 12AY7, one 6CG7
• Analogue inputs One pair balanced (via XLR connectors), one pair single ended (via RCA jacks)
• Analogue outputs Two pairs of speaker taps (via 5-way binding posts)
• Power output 80Wpc RMS @ 6 Ohms
• Bandwidth Not specified
• Sensitivity 600mV for max power
• Distortion 0.07% at 1W/kHz, 1% at 80W
• Signal to Noise Ratio > 90dB A weighted
• Dimensions (H×W×D) 210 × 260 × 410mm
• Weight 16kg
• Price £3,249 each

Manufacturer

Synthesis

www.synthesis.co.it

UK distributor

Henley Audio

www.henleyaudio.co.uk

+44(0)1235 511 166

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