OPINION

There's probably something unfathomably deep you could say about digitally sampled pianos. About how the simplest of concepts - a piece of wood hitting a piece of metal - can only be mimicked by the most complex technology.

Or you could just say there's a lot of it about. Korg and Roland both had keyboards at the Frankfurt show dedicated to playing back samples of real acoustic pianos. But the most surprising entry into the field was Technics with three versions - the £899 PX5, the £1,249 PX7 and the (grand) daddy £3,599 PX-1 (all prices excluding VAT).

At more than £4,000 with VAT, the PX-1 is plainly intended as the market's Rolls Royce. Most of us will benefit from Technics' research with the 5 or 7, but the PX-1 is a perfect place to start for considering what's involved in reproducing a grand piano.

Firstly, the principle of sampling - digital recording of an acoustic sound, and replaying it at new pitches from a keyboard - is not new. A machine that has pre-set samples, like the Technics, is easier to produce than a machine where you do the sampling yourself. It doesn't need the recording circuitry.

A sampled grand piano is an obvious first choice - it's bound to be closer to the real thing than a synth because after all it is the real thing. That said, samples quickly deteriorate in realism if they're asked to do too much. You can't record just middle C and expect that note, played back at different rates, to cover seven octaves. Multi-sampling helps. Keyboards like the Ensoniq Mirage will use eight separate samples spread across the keyboard so none is stretched too far. The PX-1 has 80.

Of the 88 wooden keys, 80 of them trigger their own, dedicated sample of just one matching note on the real instrument. To be completely accurate Technics in fact take up to seven samples for each note at varying strengths (a poor pianist sits there and hits they key a bit harder each time). That way you hear a true change in timbre - pianos get brighter, richer, fuller and sweeter as well as louder when you strike the keys more forcibly. Seven samples are used for the mid range of the keyboard where the timbre changes the most, five for the bass and three for the top.

The PX-1 has a true piano action. There are even fake hammers to assist the bounce, produce a psychologically pleasing mild thump, and give the feel of a balanced, fulcrumed action. The only discernable difference is in when the note starts. You will always hear a note, however softly you press the key, because an electronic contact is made. On a real grand you'd get no sound because you wouldn't have applied enough strength to move the hammer and hit the string. Not a problem, just an intriguing detail when you discover it.

To the sound - six choices in all: a 9ft Steinway and a shorter Bluthner (my estimates, Technics are too cautious to say), a brand new Fender Rhodes all clear and spangly, a dirty, percussive Fender Rhodes that's seen some beer and action, a harpsichord and a D6 Clavinet. Yes, I know there's no such thing as a D6 seven octaves long. They stretched the low notes.

The Steinway is bright, long and deep - a real physical presence when you thump (sorry classical-types) a chord. Hard to ignore the impression that, a foot in front of you, something wooden with strings is vibrating pianistically. The dynamic polling of samples is convincing. Soft, reserved tones at one end; bright ringing overtones at the other, with variations in extra body and harmonics in between.

You start listening to obscure details like the slight phasing in the bass notes as the two or three strings of the genuine article beat with each other. When you swap to the Bluthner you'll hear a rounder sound with a tighter bass end from the shorter strings. Perhaps more of a rock'n'roll piano, especially with help from the onboard EQ.

All the PX-1's controls are on a strip above the keys, in front of the lid (which lifts up to reveal the fake hammers striking a rubber bar). Most are on sliders, and the dull, somewhat old fashioned cosmetics are one of the few criticisms. Main volume, pitch and transpose are partnered by bass and treble sliders, and a mid-range parametric. This helps push the Bluthner through to the front of the band. The equaliser can be pre-set and punched on and off, and another, nearby slider will artificially shorten either the decay (for a snappier attack) or sustain. While on sustain, there's a foot unit with the proper three-pedal arrangement of a grand - dampers and sustain left and right plus the unusual one, sostenuto. Clever this. You hold down a note, press the pedal, lift your fingers and the note carries on as it would with the sustain pedal. But any new note dies away normally, unsustained.

That leaves us with the new Rhodes featuring an authentically muddy mid-bass region, realistically sharpened by the EQ to bring out the percussive kick of the tines. As you hit harder, the timbre not only perks up, but the sound chokes, decaying more quickly as genuine tines would do if they were bashed hard. The old Rhodes is crankier still, a few handfuls of gravel having been tipped down the back. Though the remaining harpsichord and clavinet are eminently realistic in the noise they make, this time the piano action works against authenticity. D6's were like feathers in comparison.

Elsewhere the Technics gives itself over to being a MIDI controller, with the essentials of assignable splits and MIDI patch changes, if not the more elaborate options you'd find on a purpose built mother keyboard. Considering the length of the PX-1 and where you might by playing on it, Technics did well in adding click stop sliders to take connected MIDI synths up or down by three octaves.

The onboard sequencer is programmed in real time, remembering dynamics, but is conservative on memory (2,700 notes max) compared to the sophistication of the PX-1 in other departments. It's not meant as a store for longer compositions, however. The optional SY-FDS floppy disc recorder expands the storage to 27,000 notes - long enough to keep playing while you visit the kitchen for tea and a light snack.

For the rest of the range, the PX-5 and 7, you obviously lose details such as the wooden keys and fake action, and the number of samples decreases. But even the smallest version offers remarkable realism and with other companies yet to announce their sampled piano prices, it's easily the cheapest. As for the PX-1...

DECISION

By far the most luxurious of the sampled grands around, and the one most likely to win over addicted, professional, grand piano exponents - if any can. The degree of expression, thought and detail applied to the sampling and action is unprecedented. Technics currently have a name for organs and home or fun keyboards and they need a 'reputation-machine' to help them break into the professional market - near the top, judging by the price. Despite the slightly dated cosmetics, the PX-1 could be it.