Chord CPA2500/SPM650 review

Chord has made quite a splash about its arrival on the hi-fi scene, offering futuristic, high-power amplifiers with - wait for it - switch-mode power supplies!

The CPA2500 and SPM650 are the company's entry-level models. They're a largely conventional construction inside a square box, the various outrigger rods and pillars being entirely decorative (but then we're all in favour of a bit of visual extravagance now and then).

What's really important is inside, of course, but the assembly is smart and rugged and the overall look very smart.

Lower power

With an output rating of a mere 130 watts, the SPM650 is considerably less powerful than other Chord models and thanks to the switching supply, it is one the lighter amps among its peers.

Switching supplies still have a mains transformer, but it operates at a much higher frequency than 50Hz and can hence be much smaller. The main potential problem is one of interference, but Chord deals with that by using suitable filtering, intelligent layout and screening (internally, the case is divided in two with the audio stages at the rear). The output stage uses MOSFETs and the circuitry is entirely discrete.

The preamp, with a much smaller power consumption, uses a conventional power supply and is generally quite a straightforward device. We were intrigued to find that, although the volume readout is digital, volume control is, in fact, handled by a good old ALPS potentiometer, a multi-gang device, of which one gang drives the display.

The balance control lacks a centre detent, but is easy enough to centre up by eye or, indeed, by ear!

Strong bass

Although one listener found this combination a bit soft-sounding and never quite got on with it, the others thought it rythmic and involving, with an energetic presentation and
a particularly natural balance.

It has good bass, (extended, clear and well-defined in terms of both pitch and timing) and plenty of detail in the midband. The treble didn't seem quite as assured, though, lacking a little sparkle compared with some.

In fact, it does appear that these amps specialise in a bass-based performance. This has its ups and downs, depending on the music and your tastes, but does tend to make for good urgency and drive.

Lively amps

One of the best illustrations of how this can work was provided by the piano track, a particularly catchy bit of boogie-woogie which has some exceptionally confusing syncopation.

Heard through the Chord amps, this seemed almost possible to follow clearly (it's a very good recording, just deliberately misleading playing!), but the tonal character of the piano itself was not as clear and open as we'd heard.

This suggests there's a bit of a compromise between medium and message, which isn't necessarily a problem. The sound of instruments and voices is not seriously disadvantaged and, in fact, massed voices seemed very well served, with excellent spatial definition.

It's hardly surprising that anything of a rock'n'roll nature does very well, with a real temptation to turn up the volume. Indeed, the very slight treble helps at high levels, reducing any tendency for brightly mastered recordings to irritate the ear. A lively pair of amps with much to recommend them.