Last year, however, Rega shocked all and sundry by launching a pair of distinctly higher-end components in the Isis CD player and Osiris integrated amplifier. At $9000 a pop, these are dramatically more expensive than anything the company had previously made and forced more than a few of us to sit up and take notice. Even at their exalted prices, they offer good value. Their build is very substantial indeed, and their finish is to an extremely high standard. The styling may not be to all tastes -- there is something Darth Vader-ish about them -- but you can’t argue with the execution, which makes the output of some well-established high-end brands look crude. The sound is pretty damn special. I was completely enthralled by the Isis, which manages to bring a degree of musicality and cohesion to CD that very few players can match.

Then there was more surprising news from Southend’s most successful turntable builder: that this purely solid-state company was developing a valve version of the Isis. This seemed very odd, until I discovered that the company’s head of electronic engineering, Terry Bateman, worked with tubes in designing musical-instrument amplifiers before he joined Rega. Less surprising, he used glass to power his own home system. So it kind of makes sense, but I was nonetheless taken aback to discover that he’d spent the last ten years developing this player. This may have been how long it took him to persuade Roy Gandy to put it into production.

he thinking behind the player differs from that espoused by most companies making tube equipment. With the Valve Isis, Terry was looking to continue the style of amplification used by many musicians. Tubes have, after all, been in use in instrument amplification since electric instruments were first made, so there is a logic there, albeit one that is slightly at odds with the goal of high fidelity. Musicians use tube electronics for the tone they produce and the way they behave when pushed hard. But these are not necessarily what you want when trying to find out exactly what recordings sound like at our end of the chain. We want to hear the colorations that the musicians produced and the engineer captured, untainted by any extra distortion. The glass aficionado’s answer to this is that transistors have their own shortcomings and these have a similar coloring effect on the end result. This does not of course stop many audio enthusiasts from achieving fantastic results with tube amplification. I have heard some truly beautiful and totally engrossing glass-powered systems over the years and only wish I could afford more than just my Border Patrol tube preamplifier.

The Valve Isis has a differential tube output stage based on an instrument-amplifier circuit. It employs triple mica 5814A (ECC82/12AU7) triodes, which are followed by two ECC88 (6DJ8/6922) triodes that form the output buffer and transformer driver stage. The player uses transformers for its balanced outputs, as is usually the case with tube designs. Rega states that it didn’t use tubes "to make [the Valve Isis] sound warm" but used industrial circuits to make an "articulate and competent" player. Apparently a "very modest" amount of feedback is used to keep things stable.

Unlike the solid-state Isis, which has a pair of Burr Brown PCM1794 digital-to-analog converters, the Valve model uses Wolfson WM8741 DACs. Both are 24-bit/192kHz chips, but the Wolfson has a differential output, which clearly suits the differential output stage of the Valve model. Elsewhere Rega has employed polypropylene or polyester film caps in place of small-value electrolytics in critical locations, with audio-grade electrolytics being used where large values are required.

There is a switch on the back of the Valve Isis that’s specific to this player and offers three filter settings. The first (F1) is a linear-phase half-band filter, which doesn’t introduce group-delay distortion but does create pre-ringing -- it’s the closest thing to the filter in the standard Isis. The second (F2) is a minimum-phase apodizing filter, which has approximately the opposite characteristics of the first filter. The third option (F3) is a linear-phase apodizing filter with no group delay and suppressed ringing.

The apodizing filter was specifically designed to minimize pre-ringing in low-sample-rate digital signals. Dr. Peter Craven, whose credits include the Ambisonic soundfield microphone and lossless data compression, invented it in co-development with Meridian. It combats the way that digital filters ring at half their sample rate, something that’s always going to be a problem for CD with its 44.1kHz rate. I have encountered this type of filter in two other players to date: the Copland CDA825 and Meridian’s own 808.3 -- players that sound so different from one another that it’s impossible to assess exactly how beneficial apodizing filters are. However, out of the three players assessed so far, two have been extremely good. So on balance apodizing helps.

More technical bits. Rega does something that to my knowledge is unique among CD-player makers: it builds three matched laser mechanisms for every Isis. One is installed in the player, and the other two are stored at the factory. Should the original mechanism develop a fault, the company will always be able to provide precisely the right replacement. That’s taking customer service to a new level.

Clearly, as much attention to detail has been paid inside the box as it has on the outside. The black chrome finish is quite unusual and suggests that it should tolerate more abuse than the livery of the average component, not that you would expect the Valve Isis to get much abuse. The back panel is well equipped with single-ended RCA and balanced XLR outputs alongside S/PDIF digital outputs in coaxial and TosLink varieties. As with the standard Isis, there is also a USB input (for signals up to 16-bit/48kHz), which is an interesting nod to the way things seem to be going. It’s not one of the much-vaunted asynchronous types, but it delivers a pretty decent result if you connect a well-presented digital stream to it.

The remote is a real brick, hewn from solid aluminum and styled to match the player. It has all the key controls plus a few initially baffling ones such as Album Up and Album Down. These are apparently for MP3 discs. The Isis can also play material burned in the .WMA format. I like Rega’s use of color on the remote. It’s reminiscent of Dieter Rams’ designs, where he color-coded the controls on all of the Braun audio components, making them intuitive to use. Other nice touches include the provision for using Rega Couple single-ended interconnects with Neutrik plugs and the inclusion of a good-quality Rega-branded mains cable with braided metal shielding.

he disc-loading lid is manually operated and sits on a damped parallelogram hinge, which is quite sexy. Opening it will stop the disc without the push of a button. In good old analog style, shutting the lid requires the lightest of touches, its weight sufficient to do the rest. The sound that the Valve Isis produces after you press Play can be totally beguiling. Put on a good female vocal, such as Gillian Welch singing "Orphan Girl" (from Revival [Almo Sounds 80006]) and you will be hard-pressed to tear yourself away, her voice sounding utterly beautiful. This player’s tonal rendering is in another league to most. This is true whether it’s a voice or an instrument, preferably an acoustic one. There is no sense of added warmth, but midband transparency is so good that you might guess that there is something hot and glowing inside the box.

Image focus is good too, which is not always the case with tubes, but the bass does kind of give the game away. Again, thanks to the supreme tonal depth on offer, the Valve Isis produces gloriously chewy bass with body and timbre to die for. This was immediately apparent when the double bass came in on Bark Psychosis’ Codename Dustsucker [Fire Records FIRE 090CD], an album that picks up where Talk Talk left off back in the '90s. You can’t beat double bass for shape and color, and in the Rega player’s firm yet fluid grip, it becomes even more entertaining. Tonal color is not, of course, purely the domain of acoustic instruments and voices; there’s plenty of it to be found across the board. Frank Zappa’s tune "Apostrophe," from the album of the same name [Rykodisc 10519], features George Duke on electric piano with a tremendous fuzzbox effect. This along with the power of funk that Duke injects into the piece takes a lead role, until Zappa lets rip with a characteristically bizarre guitar sound during the solo that makes the piece so essential.

The Valve Isis's filters are easier to differentiate than is often the case. F1 sounds more compressed than the other two, while F2 has more obvious leading-edge definition and greater punch. However, it is the final filter, F3, that is most appealing, thanks to its organic and relaxed demeanor. F2 can work well with more sophisticated recordings, but it gets a bit brash with crudely recorded discs. In such instances, the more juicy, tubey sound of F3 is once again the preferred option. You have to access a switch on the back of the player to change filters. A remote-control option would have been nice, but it didn’t take long to figure out which setting suited my room and system best. It turns out that Terry Bateman also prefers F3.

In terms of imaging, this player is extremely good at projecting the music into the room. The instruments escape even large speakers with ease, which makes suspending disbelief quite easy. It produces a genuinely physical sound with real body and presence. It works on both macro and micro levels; you can follow the music as a whole or listen to individual musicians and appreciate the character of their instruments or voices and what they are doing with them. Having said that, the best voices are a big distraction -- in the best possible way. Frazey Ford on the Be Good Tanyas' track "It’s Not Happening" (from Chinatown [Nettwerk CD 303042]) is a real heartbreaker on this player.

Next to the standard Isis, the Valve brings quite significant improvement in tonal resolution, but it sacrifices some of the timing qualities of the tubeless player. The solid-state model has an ability to engage the listener that’s second to none, and while the Valve is also extremely good in this respect, it can’t quite match its slightly more affordable stablemate. Which one you prefer will depend on your priorities and musical tastes. If the latter includes a lot of acoustic instruments and voices, then the tonal finesse of the Valve is going to win the day. And electric instruments have plenty to offer too. Another Zappa track, "Stinkfoot" (Apostrophe again), features a guitar sound that I’ve never heard elsewhere -- or heard portrayed quite the way the Valve Isis does it. What is it with guitar players these days? They’re just not copying the right people.

Whilst the Valve Isis was in residence, I enjoyed an all-too-fleeting period with a Metronome Kalista Intégré, an alarmingly expensive French CD player (£38,000 here in the UK, $65,000 in the US) that does everything so well that it almost seems like good value. It made the Valve Isis sound positively dark in tonal terms, but it didn’t dramatically improve on its musical qualities, even if detail levels were in a different league. Rega does not appear to voice its products to sound as immediately appealing as possible, but it does go to great lengths to make them musically compelling, which is arguably the most important quality for a piece of hardware to have. I have enjoyed some wonderfully revealing and refined components that didn’t really make me want to listen to music once I’d gotten used to them. The Rega Isis in both its guises encourages a thorough re-evaluation of your music collection just to hear how good preferred albums really are.

he Valve Isis has color and dynamics, heart and soul. Its sound is not super-detailed, because it puts the emphasis on the music rather than any audiophile qualities the recordings may have. This means that it may not be an instant hit in the demo room. Do not expect to be wowed; rather, expect to fall in love. What more can you ask of a musical conduit?