We've seen plenty of CD players with valves, but we haven't seen any that look as though they're giving a valve amp a piggyback. Icon Audio makes a large range of glass-powered amplifiers. It has also been responsible for a number of CD players in the past, but none that were this hardcore.
And that's why the output stage on the CDX1 has its own hard-wired chassis and valve power supply. In fact, the CDX1's designer David Shaw wanted to make a proper output stage, rather than the usual addition of small triodes to a regular transistor circuit.
Best valve ever
The separation of digital and analogue sections is pretty comprehensive in this player, Shaw has designed an output stage in the style of an amplifier rather than a source, which explains why it's so obvious on the machine.
It has a choke-regulated power supply with valve regulation, courtesy of the brightly glowing 0A3, providing the HT voltage and absorbing RF noise. The smaller EZ80 is a valve rectifier and provides a slow start warm-up for the big 6SN7 output devices. Avoiding what's described as 'cathode stripping' has a very positive effect on valve life.
The 6SN7 is described by Icon as 'probably the best sounding hi-fi valve ever' which is a controversial statement in the context of more fashionable valves like the 300B. But David Shaw is very keen on this device and uses it to drive big 845 triodes in the company's most aspirational power amplifier, the MB 845 MkII.
The actual valves supplied with this Signature version of the player are Shuguang Treasure Series CV-181Zs which are a rather more expensive equivalent of the 6SN7. The two black lumps that flank the glassware are transformers, one is a choke regulator which supplies the rectifier and the other is the mains transformer.
The player itself is an off-the-shelf Chinese machine, with a Philips mechanism that was chosen because David wanted something that was devoid of surface-mount circuit boards and because it's solidly built.
The steel casework is indeed heavier gauge than usual, which must help when it comes to supporting the transformers on its top. Being solid also helps keep resonance under control, which is always a good thing.
The DAC is an AK4394, a 24-bit/192kHz upsampling type.
The CDX1 actually has three sets of outputs on its rear end, one marked 'valve output' and another two in RCA phono and XLR forms just marked 'output'. The latter it turns out connects to the standard transistor output stage, so for obvious reasons you are encouraged to use the pair of RCAs hooked up to the glowing parts.
The digital side of the player can be accessed via a pair of inputs for coaxial and optical connections, while digital output is only available via an optical TOSLINK connector, but if you want something to use as a CD transport there are numerous more affordable options on the market.
The glass war
The CDX1's build quality is not as slick as some at the price, but neither is it crude. In fact, with the copper plate under the valves and the signature plate it looks rather good.
The front panel is anodised, aluminium and is cleanly designed, while the lump of amplification on the back marks the player as something out of the ordinary. The remote is an off-the-shelf type, but that's usually the case and it's attractive enough with an aluminium facing and rubberised finish.
What's more, it has direct-track access and that most important of all keys: eject. We also like the way that the digital inputs can be selected via a toggle switch on the front.
The David Shaw Signature version of the CDX1 costs £350 more than its standard brother, for which you get the aforementioned Shuguang premium valves and Jensen copper foil in paper capacitors, huge handmade devices that are claimed to have a very positive effect on the end result.
There are a few tube-powered CD players available in this price range but none have fared terribly well in our tests. The Audio Analogue Rossini VT 2.0 (£1,200), Prima Luna Prologue 8 (£1,500) and Shanling CD2000 (£1,000) all failed to garner recommendation.
The hybrid players that we have liked from Copland, Consonance and Ayon are all rather more expensive. The Icon is closer to the latter two in terms of sound, but has more features by way of its digital inputs and beefier output tubes.
While size is clearly not a major issue it does, in Icon's opinion, make for a longer lifespan, which is reassuring.
It's no fool
The CDX1's sound has many classic valve qualities; it is relaxed, smooth and spacious with some emphasis on the midrange, but not quite the bass extension of solid-state players.
Its own solid-state output has more bass power, but a considerably less vivacious presentation. There is no shortage of life in the valve output's sound and with transistor amplification and evenly balanced speakers, this makes for a vital and entertaining result. A result that varies quite considerably with recordings, with one seeming a little overly laid back and the next coming through with remarkably clarity.
It likes a good recording, that's for sure and isn't fooled by studio trickery, inasmuch as the less manipulated discs sound cleaner and more open than those that have been engineered to sound pure and open in-the-box (that box being a computer running Pro-Tools or similar).
So Keith Jarrett and Charlie Haden's Jasmine is totally effortless, yet solid and real, sounding totally in-room through a suitably capable system.
While valves do not measure all that well in signal-to-noise terms, they manage to present a subjectively more dynamic result than their 'quieter' solid-state brethren. This was immediately apparent with a fine recording of Schubert lieder, where the dynamic range of the voice required a bit of gain riding, so that we weren't pinned to the back wall.
Simpler material like this works better than full orchestral extravaganzas, where the strings can harden up a little when things let rip, but there's no denying the drama of a piece like Beethoven's 7th in the Icon's hands. The bass may not be weighty, but it is very articulate and you can easily follow bass lines.
Some get distinctly cleaner in these circumstances and there's a strong argument for this balance in terms of musicality. There's no shortfall in drive or tautness and you can enjoy the timbre of instruments and voices without trying.
This player brings a degree of humanity to CD that is quite uncommon, particularly at this price. It does emphasise the midband a little and this means you can understand lyrics easily.
This transparency, combined with a fluid and relaxed presentation, makes for great listening. It's very easy to relax and tune in to the music. It's not a soft or cozy player and give it something chunky (like Wyclef Jean's Thug Angels), turn the wick up and the place will start jumping.
The CDX1 has a remarkable balance of sound, build and features at the price and makes much of the competition seem just a little bit dull.
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