The 202 isn't one of the brand spanking newest Casios, but it's definitely a peak against which all later developments will have to be judged. The original Casiotone 201 brought polyphonic synthesisers down to everyone's pocket.

Okay, so it didn't have the classic wangs and wahs that more traditional synths have, but its digital technology gave it a range of crystal clear piano, organ, harpsichord and bell-like tones that many other keyboards, ten times the price, couldn't match for sheer sparkling clarity.

But as the first musical instrument from a company used to building watches, tills and calculators, the 201 had mistakes. Its heir sets many of them right.

Gone is the 201's phono socket output and lack of tuning. All sockets on the rear panel are now jacks and a screwdriver-adjusted pot will alter the pitch. Like its predecessor the 202 uses its own keyboard to select the sounds — but there are now 49 instead of 29. In the select mode each of the keys becomes a switch and can load a choice of four desired voices into the memory. The four position memory on the 201 was a click and stop slider and that's been replaced by individual push buttons.

So it's a matter of choosing a memory position, flicking on the "set" switch, pressing a key (say middle C for koto — all keys will sound an A in their assigned voice when the Casio is in "set") then moving the "set" switch back to "play". From then on the whole keyboard will reproduce a koto, and the other three memories can be filled with alternatives for fast, between number changes.

The 201 only had voices on its white notes, the 202 gives over the black notes as well and also has a choice of three different types of vibrato — slow/deep, fast/deep and fast/slight represented by wavy lines on a grid background. It's a pity they missed slow/slight as the others can be overpowering.

The volume is now on a slider and all controls have been moved to the left of the keyboard which is handier for the player used to dealing with synth pitch and modulation wheels. The daft plastic overlay has gone; all voice titles are permanently printed, the two pin mains socket has been replaced by a safer Euro plug and the body is flashier with a silver trim and sides. It's a few inches longer and annoyingly won't fit into 201 carrying cases.

Casio have done their homework sorting out almost all the ergonomic fingers in the eye that afflicted their first child. Despite suggestions they haven't included a chorus unit and I recommend it as an additional purchase if you want to wash away the clinical digital sounds. Some voices are best suited to a crisp, brittle edge, but others can do with some extra meat on them.

A couple of 201 selections have been dropped, including bell lyre and glockenspiel, though others approximating them have been taken on board.

In fact Casio have laboured on more than the exterior image. The electronics have been juiced up. Sustained voices such as organ, clarinet and brass seem broader and the secondary "whaaa..." sounding break-up that afflicted percussive selections has been eliminated in most cases.

There are also a handful of lower pitched voices balancing the Casio's over concentration on tinkly tones — bass and electric bass take the scale down at least two octaves.

What you really get on the 202 is more choice. For a start, four pipe organs from the clear and trebly number one to the cathedral rich number four, and then the coy, calliope-like electric organ. Even more impressive is the clav with a fine twangy hollowness close to the real thing.

The two harpsichords demonstrate the Casiotone's talent for sparkling, crystal clear tones — one is bright and toppy, the other has an underlying mix of organ for a thicker, fruitier quality.

There are four harps all with differing attacks and tones, the first being the sweetest featuring a flutey, mellow tone but jazzed up by a sharp, poppy synth blip to the attack.

The two kotos shared similar characters but over a more nasal sound.

There are something like eight different guitar settings, and it's here that the Casio designers have been desperately filling space. Only half of them deserve to be there as the others are merely slight changes in tone or bite. And as on the 201, the cello, violin and viola string sounds are among the weakest.

The brass and trumpet settings are stronger having depth and brilliance. The 202's mellowest voice is horn and it's about the best for silky, background chords and like the pipe organ and brass, benefits heavily from a brush with a chorus unit.

There are a few duffers among the selection. Bagpipes are wee wee, and the accordion is accurately wheezy, but underwhelming, likewise taisho koto is Sparky's Magic Piano through a Kleenex tissue. At times the sustain is unnervingly cussed to control and you can only get the full decay by hitting the keys and lifting your hands off sharpish.

But the 202 handsomely redresses the balance between spangly voices like the clavichord that gleams through even the mushiest band sound, and fuller, background material such as the pipe organ. The 201 had plenty of the first, few of the latter.

£325