The Mystère ia21 has a far more fast-paced, far more up-beat sound than most of its valve peers. In other words, where most valve amps at this level have an old-school conradjohnson rose-tinted sound, the Mystère is more like Audio Research – big, bright and fast. No, it’s never going to sound as crisp or as upbeat as the transistor superstars (the Naim Supernait costs not much more than the ia21 and holds all the rhythm aces) but for a valve amp – particularly a valve amp that costs the right side of two grand – this is good stuff. It means the ia21 is pacey enough to keep up with the quicksilver dynamics of Rachmaninov’s Symphonic Dances or motor-mouth Eminem rapping, but always manages to keep a beat no matter how difficult things become.

Don’t think this amp loses the advantages of valves for that tighter, brighter sound. The amp almost behaves like a hybrid, with the air, space and coherence of a good valve amp and the upbeat tempo of transistors: especially coherence, something many people seem to overlook in the pursuit of starkly precise and often arid transistor sounds.

It must be because coherence is one of the most abstract elements to get across. We tend to compartmentalise our world and the same applies to sound. It’s why soundstaging is all important to many hi-fi enthusiasts – if it’s easy to separate out individual sounds within an image envelope, they can be categorised, logged and defined (and, incidentally, the ia21 does deliver a very good soundstage – slightly wide of the boxes, projecting deep behind the speakers and relatively far forward, with some height). Coherence, on the other hand, is less easy to fit into a neat pigeonhole, because it plays a long game. You listen to 20 seconds of music and will hardly notice whether the instruments appear to play better together. You won’t be able to tell whether the character of an instrument voice remains consistent across its whole range and in front of a range of instruments. Only time will tell, and it’s that time that does wonders for the Mystère. There’s an organic sense of flow here, which many amps struggle to maintain. The more you listen, the more natural the Mystère sounds and the more you relax into the sound. Naturally, such a luxuriant coherence can only occur when an amplifier has remarkable articulation, and here every nuance of the playing or singing is reproduced with precision and élan.

Where the limits begin to show is in the control at the bottom end. This is not an amplifier for full-range speakers, especially those presenting a difficult load. The pace is a result of slightly curtailing the lower frequencies. This has a knock-on effect in the solidity of sounds within an image. The sense of rootedness you get when playing a beefy powerful amp is not that strong here; it’s not unnerving, and images do not float around the soundstage, but there remains a vague sense of dislocation, particularly with percussion.

All things are a trade-off, however, and if the trade is some solidity for a more honest and more up-beat sound, it seems more than worthwhile. This may not be the amp for those with vast speakers, but I suspect the intelligent vast speaker buyer will be spending far more than the cost of the ia21 anyway. This is a welcome addition to the lower price valve pantheon; it brings much-needed pace to the party and sacrifices little to get there. That it comes from the Prima Luna stable and manages to sound so very different from that range reflects both the designer’s skill and his conscious decisions. If you always hankered after something that combines the pace of transistors with the richness of valves – but were not prepared to go the hybrid route – there’s no Mystère… this is the amp to go for.

Conclusion