Synthesis Soprano LE Integrated Valve Amplifier Review

The Italian Job

by Ed Selley
Hi-Fi Review

10

Recommended
Synthesis Soprano LE Integrated Valve Amplifier Review
SRP: £1,449.00
8
AVForumsSCORE
OUT OF
10

Synthesis Soprano LE Integrated Valve Amplifier Review

The Soprano LE is a product with far more mainstream appeal than the basic specification might let on. It's beautifully made, has more poke than you might reasonably expect and is consistently fun to listen to. It's a fine value valve amp.

Pros

  • Sounds excellent with far more real world headroom than you'd expect.
  • Well made
  • Good connectivity

Cons

  • Limited sample rate handling on the USB input
  • Only one RCA in
  • OCD triggering volume indicator

Introduction - What is the Soprano LE?

The Synthesis Soprano LE is an integrated amplifier with a selection of digital and analogue inputs. We test plenty of these but you’re probably already entirely aware that the Soprano LE is a little bit different to the usual type standard of what passes for an integrated amp in 2021. In isolation however, the specification it possesses make it potentially interesting for many people who might not have been considering valves up to this point.

We have also demonstrated that valves in themselves are not an impediment to a product being entirely practical for day to day use as judged by the sort of people who frequent this site (rather than that practicality being judged by the sort of people who regard changing the oil every 1,500 miles in their car to be ‘precautionary’). Likewise, I have done my best at various points to explain how much power you might actually need in a real world situation (‘less than you might think’ being a fairly neat summary of that). In short, nothing that the Soprano LE does is intrinsically ‘out there.’

There is of course, some distance between ‘not completely deranged’ and ‘actually something you would want to buy’, so we’ll treat the Synthesis to the standard shake down and try and avoid the standard pitfalls of ‘valve magic’, ‘beguiling warmth’ and - this being an Italian product after all - ‘character’ and ‘soul.’ Is the Soprano LE how you, a normal (to a given value of ‘normal’) person should choose to spend £1,449? Let’s find out.

Specification and Design

Synthesis Soprano LE

Off the bat, the most interesting thing about the Soprano LE is that it differs from anything we have tested on AVForums before and indeed from any other amp I can remember testing. The reason for this is that it is a hybrid; a combination of valve and solid state operation. Usually, this entails taking a beefy solid state power amplifier and putting a preamp that makes use of one or more valves in front of it. The idea is that you can induce a little benign colouration to your otherwise down the line amplifier.

The Synthesis turns that idea on its head. This is an exclusively solid state preamp. In fact, not only is it solid state, it has some attributes that are very of the moment indeed as it makes use of a rotary encoder (that is to say that the volume has no start and end point and no indicator to that effect on the control itself). This collates a selection of inputs that ensures that the Soprano LE is fairly flexible. An RCA line input is joined by a moving magnet phono stage (also entirely solid state) and one optical and one USB input.

In the case of the latter connection, a little care needs to be taken because it’s a USB 1 type device that supports a maximum sample rate of 16/48 which is a trifle limiting in a world where Amazon flogs you Hi-Res for a tenner a month. On the plus side, this doesn’t require any form of driver to work with a PC, making it fairly stable. The optical and coax inputs are good for 24/192 however which gives some further options. No headphone connectivity is supported and there’s no Bluetooth either; something you might be going ‘well duh’ about but that was fitted to Quad’s lovely and sadly departed VA-One which is perhaps the closest thing to the Soprano LE that we’ve ever tested.

Synthesis Soprano LE

This preamp feeds its signal and gain information to a power amp that comprises a quartet of EL84 valves. These deliver 15 watts into six ohms (equating to about 12 into 8 and perhaps delivering an extra watt or so into a 4 ohm load). This is the type standard for what EL84s do and if you really need more power than this, excepting a couple of curios that use many EL84’s per channel, you’ll need to look elsewhere. It’s worth noting though that although the headline numbers generated by the EL84 are nothing to get excited about, the manner in which it delivers them is extremely robust and, if and when you do exceed its operating envelope, it tends to give in gracefully. Behind the valves are a decent set of output transformers that wind up in a small but fairly sturdy pair set of speaker terminals.

In fact, ‘sturdy’ crops up a fair few times in my notes. The Soprano LE is built in Italy - no small achievement for the asking price - and I’ve been consistently impressed with the engineering and finish. The chassis is all metal and divides the three quarter width chassis into halves, with the preamp section occupying one and the amplifier section the other (in practice, this division won’t be quite so neat internally based on the location of the inputs). Everything feels solid, considered and confidence inspiring. It is possible to spend a great deal more than this on a valve amplifier and not enjoy the same feeling of solidity. Mention also has to be made of the remote handset which puts devices that have been sent here at three or four times the price to shame.

Synthesis Soprano LE

This is not to say that there aren’t some quirks to the operation though. The most significant of these stems from the operation of the preamp. As noted, this has no volume indicator of its own. The level of the Soprano LE is denoted by a single LED above the knob that starts green and climbs through yellow, orange and finally, like the Ancient Mariner, a still and awful red. In theory, this is fine as an indicator of how you are using the amp but psychologically it’s a bit odd. For starters, the operating portion of the Synthesis denoted by green (a colour I have been conditioned by years of subliminal education to consider ‘good’) will be completely inaudible unless you have some very sensitive speakers indeed. On test, the Soprano LE has operated in the yellow band, varying between shades I would describe as ‘Golden Delicious’ for low level through to ‘Berocca’ for fairly loud. What’s more, each time the Soprano LE is switched on, the volume will reset to an inaudible level which can initially be somewhat confusing.

Everything else though is logical and undemanding and, crucially, not going to unsettle anyone coming from a solid state background. Aside from a longer warm up time, there’s no valve histrionics; no humming, speaker destroying thumps or the little ‘tink tink’ noises that very hot and ambitiously melty things make. Like the Prima Luna Evo 300, it makes few demands a normal piece of audio equipment wouldn’t.

One quick note, more relevant to anyone reading this review months after publication is that the Soprano LE is - as the name suggests - a limited edition model of 200 pieces. The review has been undertaken on the understanding that there is a reasonable quotient of these units as yet unsold and, once they are, there is a non special edition Soprano that is mechanically identical save for finish and some detail alterations to the analogue input and speaker terminals.

Synthesis Soprano LE

The Soprano LE is built in Italy - no small achievement for the asking price - and I’ve been consistently impressed with the engineering and finish

How Was the Soprano LE Tested?

The Synthesis has been connected to an IsoTek Evo 3 Aquarius mains conditioner and has taken an input from a Roon Nucleus over USB and via an M2Tech USB to S/PDIF converter into the coax input. A Chord Electronics Hugo2 and 2Go have been used to test the analogue input while a Rega Planar 10 fitted with a Vertere Sabre moving magnet cartridge has been used to test the phono stage. Speakers used throughout have been the Focal Kanta No1. Material used has included FLAC, AIFF, DSD, Tidal, Qobuz and vinyl.

More: Audio Formats

Performance

Synthesis Soprano LE

I am - in so many ways - a simple soul. There are a few words and terms that crop up in audio that largely confirm to me that I will enjoy myself and ‘quartet of EL84’s’ is one such phrase. I am sure that somebody somewhere has mangled an EL84 based circuit to the point where it no longer sounded pretty good but it does seem to be something you would actively have to work at doing. It means that the Soprano LE is off to a good start by dint of being built around such a device. “Yes” you say “that’s great Ed but 15 watts is just not enough, it’s irrelevant.”

Now, if you’ve a barn to fill or some ATCs to drive, this might well be true. The thing is though, it probably isn’t. As I type this, the Soprano LE and Kanta No1 is playing Fireproof by The National and it is playing it loud. The light is the colour of ‘early sunset’ and a calculation with a voltmeter (and a friend who can count) suggests I am using a whisker over nine watts. Sure, the Focal is pretty sensitive but not outlandishly so and a few speakers I’ve looked at occupying more terrestrial price points - the Fyne Audio F500SP and Triangle Borea BR08 in particular - are more sensitive and more efficient still. My point is that, with a little bit of thought put in, the Soprano LE has more oomph than you might think.

I am pretty certain that, were you sat where I’m sitting, you wouldn’t be terribly interested in volt to watt calculations though. Instead, you’ll note that Matt Berninger is in very good voice indeed and the presentation he is a part of sounds big, vivid and effortless. In the course of testing, I have used the USB for a little bit of listening before moving - and largely staying - on the coax input taking a feed from the USB converter. It works better (and if you don’t fancy that sort of faff, you may recall iFi’s ZEN Stream has a coax out ready to go, as does the Bluesound Node) and it delivers an overall presentation that plays to the strengths of the topology without giving in to too many of the weaknesses.

Synthesis Soprano LE

Those weaknesses can largely be narrowed down to the bass extension. For me, subjectively, the Soprano LE has ‘enough’ bass. It is never going to trouble the effortless low end shove that a Supernait 3 brings to the party but it’s never so light that what you are listening to becomes unconvincing. Instead, there’s a leanness that, when combined with the commendable control that the Synthesis possesses, leaves it sounding surprisingly energetic. Does it relay the full bombast of the Mammoth WVH album? Maybe not… but it puts up more of a fight than you might expect it to.

Throwing a few grand’s worth of decoding at the Synthesis in the form of the Hugo2 brings a few detail improvements; a little more bass extension for one, but the basic character of the amp is decided by the EL84s and that’s no bad thing because that fundamental rightness of tonality and soundstage permeate everything it does. So long as you can find a way to use the optical or coaxial inputs, the on board digital is quite sufficient.

You can also console yourself that any additional expenditure on the digital can be recouped on the analogue. The phono stage of the Soprano LE is genuinely lovely. I put on a copy of Arcade Fire’s Funeral to get a basic handle on what it can do and wound up happily listening to the whole album. Does it present the same accuracy and grip that running the Rega into the resident Cyrus Phono can? No. Is it wholly and endlessly pleasant to listen to? Oh yes. With bells on. If you do a fair bit of your listening on vinyl, this is a bit of a dark horse; certainly one of the better internal phono stages I can remember listening to at this sort of price point.

Synthesis Soprano LE

Does it present the same accuracy and grip that running the Rega into the resident Cyrus Phono can? No. Is it wholly and endlessly pleasant to listen to? Oh yes. With bells on.

Conclusion

Synthesis Soprano LE Integrated Valve Amplifier Review

What this adds up to is a really rather talented little amp. You could construct a streaming and vinyl system around the Soprano LE and, so long as the output is sufficient for your needs (and to reiterate - it almost certainly is), you’ll have a ball with it. What’s impressed me most in the time I’ve spent with the Synthesis is that it very effectively avoids the flaws I mentioned at the start. I’ve had to make very few allowances for its design and specification and have instead been able to enjoy its rather ebullient and personable presentation with only my mild obsession over the ‘worth’ of greens and yellows to distract me. This may only ever be a niche solution for some people but it’s rather less niche than a cursory glance at the specs might suggest and for those reasons, it comes enthusiastically Recommended.

Recommended

Scores

Build Quality

.
.
8

Connectivity

.
.
8

Ease of use

.
.
8

Features

.
.
8

Audio quality

.
9

Value for money

.
9

Overall

.
.
8
8
AVForumsSCORE
OUT OF
10

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