It may not have the highest profile in the UK, but Cairn is a well-established French company, going back to 1994. Its product range, never less than smart and in some cases distinctly futuristic, currently includes CD players and various amplifiers – there was once a loudspeaker, too.

The Diablo, part of the 'Classic' series, certainly has a classic specification at 70 watts, with five line inputs (but no phono option), tape, preamp and subwoofer outputs and, of course, remote control.

The most striking feature is surely the lone rotary knob, which is nicely profiled and surrounded by an unusual amount of legending. It transpires that Cairn has made this lone control operate both volume and source selection: rotate it to adjust volume, push briefly to cycle through sources, push and hold for a second to select tape monitor.

This may sound fussy, but it's no more trouble than more conventional arrangements and one very quickly gets used to it.

What can be a little tedious is volume adjustment: the Diablo offers nice small steps from its electronic volume control, but at only 20 steps per revolution of the dial, it takes a good spin to make more than a minor adjustment. Balance control and mute are available only from the remote.

Cairn has built this amplifier on a classic pattern, with the heatsink dividing the case in half, transformer to the left and circuit board to the right. The latter is on the small size, thanks to the use of almost entirely surface mounted components, though, of course, the output devices (MOSFETs) are 'leggy' components, as are the various supply smoothing capacitors.

Inputs are switched by relays and the volume control has good headroom, so high-output sources should be no problem.

Sound quality

Our listeners had reservations about this amplifier but still found some areas to praise. Its particular strength seems to be treble detail, which is very good under all conditions and helps make the most of bright melody instruments and also orchestral violins. Percussion within an orchestra was sharply delineated, but the rather more present percussion on pop and jazz tracks seemed a little less clear.

On the debit side, the comments centred on a degree of congestion that varied, but never quite vanished, according to the music playing. This was most evident in vocal selections, where the voice was rather less easy to follow than with some other amps and also showed up in the baroque classical track with its small ensemble of mostly midrange based instruments.

In terms of rhythm and timing, our listeners suggested that this amp is a little sluggish, somehow being late with the beat. That might sound technically impossible, but it would appear that the attack on notes somehow registers on the ear a little behind the sustain of the sound, rather than before it as should normally be the case. As a result, music that depends heavily on rhythm for its effect (rock, most obviously) becomes lack lustre and unenergetic.

There's plenty of weight to the bass and we detected no obvious tonal imbalance between bass and midrange either, but overall the timing just doesn't quite gel. Classical music doesn't usually depend quite so heavily on a regular pulse and as a result the sound is generally more convincing here.

There is plenty of dynamic contrast in evidence and the tonal character of each section of Rachmaninov's Symphonic Dances was clear and melodies easy to follow.

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