Looking really good, the Synthesis Roma 96DC+ in black

This is a look at the Synthesis Roma 96DC+ integrated tube amplifier. I gather some people think tubes are a bit old fashioned and do not sell. I am not one of them. My experience with the Synthesis Soprano 12W Class A integrated amplifier was revelatory so to be offered a 25W upgrade, doubling the power on offer, was too good to be true.

I was initially offered the Synthesis Soprano as a means to calm down the excitable, but fun, Klipsch Heresy IV horn led speakers. It worked well and led a subtlety that was not accessible with solid-state based amplification. It certainly worked for me and many of my preconceptions about solid-state amplifiers like my Naim NAP 250 were adjusted in this period, notably that it is not just all about power.

Design – Synthesis Roma 96DC+

There is a lot of learning to be had with tube amplifiers of this kind. First, there is the issue of tubes or valves, and their apparently lower relative power output compared to solid-state solutions that overtook tubes as they were cheaper and could deliver higher nominal power levels. My research, corroborated by an associate, lends me to believe that a 25W tube rating can be considered equivalent to 3 times this value in solid-state terms, so the issue of lack of power can be modified.

Next, this amplifier is Class A – analogue signal in, amplify, signal out – but this electrically results in low power output and efficiency. So, next this amplifier is a push-pull type, something I was not too familiar with in concept. It seems a push-pull arrangement uses a “combinational transistor pair in the output stage” to increase both the load capacity and switching speed to a class A

The cover of the Synthesis Roma 96DC+ comes off to reveal the tubes used in this amplifier

configuration. So, this pair operates to PUSH a transistor to ON and PULL another transistor to OFF at the same time; this means more power, yeah baby.

Then there are the tubes, there are four EL34 and two ECC82 valves, divided up between the two channels. These tubes are apparently widely used and are very reliable. It is possible if you are a ‘valve head’ to swap the tubes out to a different specification but you will have to be into this scene and ensure you do not upset the bias with the alternatives you insert.

After all this, the Synthesis Roma 96DC+ integrated amplifier has several useful inputs including a MM Phono input and two analogue RCA style inputs.  It has three digital inputs; optical (hi-res to 24 bit), coaxial (hi-res to 24 bit) and USB B which offers higher resolution support. The digital platform is an onboard premium Asahi Kasei AK4495S DAC chip that supports PCM data up to 32-bit/384kHz and DSD data up to 5.6MHz.

Just of note, there is no headphone output if that is important to you. Synthesis does offer a 2W tube headphone amplifier called the 41 DC+ which matches the 96DC+ nicely in look and style, that has got to be worth a look too, surely.

The Synthesis Roma 96DC+ is retailing at £2649.00, with Henley Audio.

Quality

The rear of the Synthesis Roma 96DC+ with analogue and digital options

There is an immediate sense of quality on unboxing with this Roma 96DC+. Weighing in at 10kg it has a powder coated finished feel to it and the review product I have has a black facia with a black body. There are different facia colour options including aluminium, walnut, red and white.

I am measuring the Synthesis Roma 96DC+ that I have as 370mm x 260 x 210 (DxWxH) which is actually different to that on the Henley Audio site so the product itself is quite deep and high which may be a consideration if you have a tight racking system, it wouldn’t fit in my standard Target based rack, for example.

The Roma powers up from a button on the front left-hand side. Input selection is simple enough on the right-hand side with a source selector at the front that cycles through the sources with a blue dot indicating the choice. There is a heavy metal remote control that manages volume and source selection, muting, with a few other functions I have not needed.

At the end of the day, the amplifier feels particularly cool to look at, if not to touch, with the glowing tubes in low light particularly pleasing, and who does not love that?

Performance

Set Up

I have had the Synthesis Roma 96DC+ driving variously a pair of Kudos Cardea C10 speakers and a pair of rather sensitive Klipsch Heresy IV speakers. My source has been the very excellent Auralic Vega G1 streaming DAC on unity output. This is a revealing system that is performing well at the moment.

Physically

The Synthesis Roma 96DC+ takes about 10 seconds to warm up on switching on. The amplifier itself, being tube based, runs very hot and the black chassis radiates a fair amount of heat, I’m glad I have mine on top of a firm table style rack with plenty of space around it. Other than that, having had it on for lengthy sessions it has been absolutely faultless, and I have been delighted with it.

DAC performance &  USB B Input

the Asahi Kasei chip is clearly a competent DAC

Taking a digital Coaxial input from my Yamaha CD the Roma delivers a fine, detailed, and comprehensive soundstage. The CD player sounds like it has had an upgrade in respect of vibrancy and energy and the Asahi Kasei chip is clearly a competent DAC.

The USB B input from my Dell XPS laptop is sparkling.  Taking input using Audivana and the 24bit/192kHz copy of Nils Frahm’s Solo the Roma translates the fizzing energy I am looking for from the tracks Ode and Some, it is a very good sound and the energy from the performance is more than delivered by the Synthesis Roma 96DC+.

Analogue Input

Taking RCA input from the wonderful Auralic Vega G1 streaming DAC, I am losing a bit of the crispness in the presentation from the G1 but it is of little concern. Unlike switching between the Precise and Smooth DAC settings in the G1 where you can only slightly feel the change on the ear with the Roma the move from solid-state amplification it is certainly more obvious, and it is even Smoother. On balance, for extended listening, the Roma is a rather relaxing experience.

MM Phono Stage

The MM phono input is fine with the Synthesis Roma 96DC+

On switching sources and lazily not turning off the streamer, happily, the phono stage output is silent, as you would expect. The phono stage is perfectly acceptable with my Rega RP3 with an Elys2 MM cartridge. You would not call it the most analytical output but for what it is, a useful option if you have a turntable anyway, it is absolutely fine. Resolution in tracks like Behind The Wall by Tracey Chapman (on the Elektra label) is very clean though and her voice is incredibly natural as you dial into her vocal and breathing. In fact, that is the theme really with this Synthesis Roma 96DC+, vocals just feel more natural than a digital source.

Switching to my RP1 for various reasons, I have the same detailed presentation that is a relaxed joy as I cycle my favourite albums over a coffee and a book on a break. Putting on Bowie’s Hunky Dory (Parlaphone) his vocal and rhythm move me to melancholy as I pause to listen to the irresistible lyrics in Song for Bob Dylan. Here I have the warmth we associate with vinyl coupled with the valves and this rolls together to give that soft relaxed vibe that seems to emanate from analogue sources.

Klipsch Heresy IV

Synthesis Roma 96DC+ paired with the Klipsch Heresy IV speakers

The Heresy IVs are tremendously sensitive speakers, and they were edgy, lively and very forward in my review of them with solid-state electronics. With a modestly powered tube amplifier, the Synthesis Soprano 12W Class A amplifier, the Heresy IV calmed down and were particularly pleasant and lighter listening. Here, with twice the power from the Roma, the Heresy have a set back image, they come across slightly deeper but still warmer than the solid-state alternatives.

I feel there is languid timing to tracks like the 11-minute long Thinking of a Place by The War on Drugs (Atlantic Records) and it just seems to last 15 minutes, I am not complaining. Resolution in these tracks remains very good with the gentle tapping of the cymbal to the rear right of the soundstage after the sixth minute elegantly placed.

Switching to the Vega G1, I played Dexter Gordon Quartet’s version of As Time Goes By (Tidal 16bit/44.1kHz) the reproduction is stunning as Gordon’s lazy tenor saxophone drifts along with a rather excitable “Sam” on the piano! The resolution delivered by this amplifier is as good as you need it to be.

Kudos Cardea C10

With the C10s the Synthesis Roma 96DC+ delivers the articulate sound that characterises the speakers and there is plenty of accuracy from the speaker. The natural unfussed sound from the Roma comes through the speakers and this is probably my preferred speaker set up with this amplifier.

Overall

there is a languid warmth and a genuine musical experience here, particularly with a turntable

This Synthesis Roma 96DC+ has been a fine companion for the last few weeks, with various speaker combinations and sources. The resolution has not been compromised and I feel the same about the power I have on offer. The output may not be as snappy and dynamic as the stunning Chord Etude power amplification that I have just said goodbye to but there is a languid warmth and a genuine musical experience here, particularly with a turntable. If you are in the market for an amplifier, this one should be on your shortlist, and I will be sticking with the Roma for as long as I have it rather than switching straight back to my usual solid-state amplification.

Specification

It is all about the style with the Synthesis Roma 96DC+

Full details of the Specification are on the company’s site