Synthesis A50 Taurus Integrated Amplifier Review

Posted on 5th October, 2023

Synthesis A50 Taurus Integrated Amplifier Review

Chris Frankland auditions this charmingly styled, seductive sounding Italian valve amplifier…


A50 Taurus Integrated Amplifier

£6,199 RRP

Synthesis is a newish name to British shores, having just been taken on by UK hi-fi distributor Henley Audio. This interesting Italian manufacturer has a wide range of products, many of which are within reach of British audiophiles. These include affordable integrated valve amps, a valve preamp, an 80W mono power amp, a CD player, a DAC and phono stage – plus more premium products like the A50 Taurus you see here.

Founded in 1992 by Luigi Lorenzon, Synthesis prides itself on aesthetics, technological research and what it calls, “an almost maniacal attention to detail”. Everything is said to be carefully handmade in Italy, with particular attention paid to the output transformers. The founder learnt to make these in his youth from his father, who set up a company called Fasel in 1961 to design and manufacture transformers for valve amplifiers, power transformers, chokes and inductors for musical instruments. They even made them for the Vox AC30 and the red Fasel inductor for Dunlop, used in the Cry Baby wah-wah, no less. When Lorenzon inherited his father's business, he decided to combine that technical expertise with his love for music and started Synthesis.


The A50 Taurus is a substantial piece of kit. Weighing in at an eye-watering 35kg, I got a twinge in my back just looking at it. Unpacking and installing such a behemoth is always fun. We poor reviewers have to do all of this for ourselves, of course, whereas you lucky punters have the luxury of your friendly local dealer who will deliver and install it for you, putting their backs out so you don't have to!

The casework is strong, and the slots cut in the front cover allow the valves to be admired, but four small crosshead screws will see it removed in no time flat should you wish to have those glowing glass bottles on display in all their glory. Keep it out of the reach of any small children though, as they do get extremely hot, of course.

The front panel has a large, central volume control, while to the far left, there is an on/off/standby button. Over on the right are six push buttons to select the four line-level RCA inputs and the digital USB or S/PDIF inputs to the built-in DAC. All RCA inputs, including the S/PDIF, are gold-plated, as well as the loudspeaker binding posts. And for couch potatoes, an infrared remote control is also provided. I have to say, I found it a little unpredictable, so I tended to operate the amp the old-fashioned way.

The A50 Taurus boasts a claimed 50W per channel into 6 ohms, courtesy of two KT88 tetrode valves per channel in push-pull configuration. The preamplifier stage uses ECC83 and ECC99s. All valves are claimed to be carefully selected and computer-matched. Synthesis says that all components used throughout the A50 Taurus are chosen for their high quality and undergo exhaustive listening tests prior to final selection.

This amp uses the company's own in-house output transformers that are unique to this model. They are said to use high-grade iron-silicon laminations for their core. Synthesis does not go into great detail as to why they chose this material for the laminations, except to say that it offers “superb frequency reproduction and width”. From what I can glean, the addition of silicon is said to increase the electrical resistivity of the iron, reduce eddy currents and narrow the hysteresis loop of the material.

One handy added bonus with the A50 Taurus is the inclusion of a built-in DAC, for which both USB and S/PDIF inputs are provided. The DAC is a 24-bit, 192kHz oversampling design using two Wolfson WM8740s, an old but much-liked DAC chip back in the day. Through the USB input, however, only 16-bit, 48kHz is possible.

When the A50 Taurus arrived, it was strapped down to a wooden shipping crate. I was eager to unwrap it and get it working and knew that the review sample had already been run-in for me, so it was good to go. My review equipment included an Audio Note CDT-Five CD player, which was fed into the Taurus's built-in DAC as well as through Audio Note's own DAC Five Special. This was supplemented by some streaming from TIDAL using the Pro-Ject Stream Box Ultra S2. Loudspeakers used included the Russell K Red 120Se and Audio Note's AN-J LX Hemp.

Whereas more purist, single-ended (one power valve per channel) valve amps tend to offer limited power and are best used with high-efficiency speakers, you will have no such limitations with the A50 Taurus. Its claimed 50W proved more than capable of driving the Russell Ks with their 86dB efficiency rating to sensible levels and with no signs of ever getting into trouble. This opens up the field to a wider choice of loudspeaker for the end user compared to many lower-powered valve amps.


This amplifier is a thoroughly modern and competent valve design – if you were expecting soft, louche, warm, woolly and romantic, then you can think again. It sounds surprisingly precise and controlled, and gives real insight into the recording. Bass is unexpectedly tight and tuneful, helping the music to gel rhythmically and move along coherently. At the same time you get the traditional attributes of a really good valve design, which include emotion, subtlety, poise, expressiveness and delicacy – it makes a very nice noise!

By way of example, the great Larry Carlton is one of my favourite jazz guitarists and it was A Place for Skipper from his Discovery album that was my first choice to hear what the A50 Taurus had to offer. The Synthesis conveyed Carlton's guitar with great precision, giving real insight into how each note was played and shaped. Nuances in his playing were clear to hear, as were the twists, turns and syncopations of the drum and percussion lines. The tautness of the bass guitar meant that the bottom end didn't dominate the proceedings, which, in turn, allowed the various layers of instrumentation to be enjoyed while appreciating how their interaction made the track as tight and poised as it is. The musicians on this recording are the crème de la crème, and the A50 Taurus showed why.

Another favourite jazzer of mine is pianist, singer, and songwriter Ben Sidran. On his Enivré d'Amour album, he does a brilliant cover of the classic On The Sunny Side of the Street. I know Sidran's voice well and have even heard him live at the gorgeously intimate venue of Ronnie Scott's in London. It was good to witness the A50 Taurus portray his vocals with such humanity, emotion and panache. Voices are something that serious valve amplifiers do really well, and so it proved here.

The bass line was tight and controlled, again defying stereotypes of valve amplifier sound. This blended perfectly with the nuanced midband and subtly detailed treble. Delicate drum, cymbal and hi-hat detail was well captured and without any splashiness or overemphasis, while the Yamaha DX7 synth had the crispness, sparkle and bite that this distinctive nineteen-eighties instrument should. The track displayed real swing, and swing is Sidran's middle name – well actually, it's Hirsh, but you get the picture!

The way that a good valve amplifier can convey the music's emotion is quite special. Some seem to be able bring an intensity to a recording in a way that leaves most solid-state designs sounding standoffish by comparison. So Amazing from Luther Vandross's Give Me The Reason was quite a thing to hear. This man is my favourite male vocalist of all time, and I am pleased to report that the A50 Taurus really did his voice justice. At the same time, Yogi Horton's masterful drumwork was also conveyed with delicacy and poise, as was the contribution from bass ace Marcus Miller.

I made a point of checking out the built-in DAC on the A50 Taurus using the Pro-Ject Stream Box Ultra S2. On balance, the performance was very good indeed. I make no bones about preferring CD or vinyl to streaming, but I bow to the latter's convenience and the fact that it opens up a whole world of music. Playing various tracks from sax player Dave Koz and a few from Van Morrison, the onboard DAC turned in a highly musically competent performance. Okay, so it may not be the best DAC you will ever use, but its sound proved very solid all the same – totally in keeping with the rest of this amplifier's attributes, then.


The Synthesis A50 Taurus is a seriously strong sonic performer that offers power, dynamics, grip, tunefulness, subtlety and swing. As such it joins a growing number of highly competent modern valve amps that I've heard recently, such as the Leben CS300XS, Rogers E20a/ii, BAT VK80i and Audio Note Cobra. At the price, the Synthesis is highly impressive then, and an essential audition if you're looking for a great all round performer.

Visit Synthesis for more information


    Chris Frankland's avatar

    Chris Frankland

    One of StereoNET’s most experienced reviewers, Chris has written for a multitude of hi-fi magazines, from Hi-Fi Answers and Hi-Fi Sound, to The Flat Response and Hi-Fi Review. A regular concert-goer, his quest continues to find hi-fi that gets as close as possible to conveying the raw emotion of live music.

    Posted in:Hi-Fi Amplifiers Integrated Amplifiers Applause Awards 2023
    Tags: synthesis  henley audio 


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