A TREND IS developing in the music industry toward rack-mount versions of existing synthesisers and samplers. These frequently offer greater flexibility and additional features over their keyboard-equipped predecessors and so it is with Roland's S220 sampling module. Derived from the S10 sampler, the S220 replaces the original rack-mount version, the MKS100. The number of available voices has doubled; new features, such as four individual outputs and the ability to store two different sounds in each bank, have been added and to bring it right up to date, it has become multitimbral as well. The sound library has grown considerably and the sounds, with very few exceptions, vary from very good to excellent.

The S220 retains the basic sampling features of the S10 and the MKS100: 30kHz or 15kHz sampling rates with 4.4 seconds of sampling time at the higher rate and 8.8 seconds at the lower rate. The sample memory is divided into four banks (A,B,C,D) which can be played individually or grouped together in combinations called structures. The split structures (A/B, C/D, AB/CD or A/B/C/D) can be used for multi-sampled sounds or can contain different sounds for creating drum sets or ensembles. The banks can also be linked together (AB, CD or ABCD) for longer sample times.

Multitimbral operation and multiple outputs alone are a significant improvement on the MKS100. The ability to process sounds individually is one of the most desirable features in any multitimbral synth or sampler and Roland have devised flexible allocation of the S220's 16 voices to its four outputs - what they call Multi Function mode. Multi Modes 1-5 allow voices to be assigned to the individual outputs as follows: as four 4-voice instruments; as two 4-voice and one 8-voice; as two 6-voice and two 2-voice; and as two 8-voice with split structures or with linked structures. The key range (highest and lowest key numbers) can be set for each bank and more than one bank can have the same MIDI channel so split and layered effects can be obtained even if your master keyboard doesn't have this feature.

A Detune mode is available that combines a structure with a detuned version of itself, as is a Delay mode with programmable Delay time, level and key offset (transposition). You can also layer sounds in the Dual mode with the ability to mix or switch between the two sounds with varying key velocity. The Separate Function divides the output of the structures between two output jacks. It's worth noting that the S220 becomes eight-note polyphonic in the Dual and Detune modes.

A new Address Velocity Switch mode allows two sampled sounds to be stored in each bank with separate start points, end points, loop lengths and loop tunings. The two sounds are called Address Groups 1 and 2 and the Address Velocity Switch sets the minimum velocity required to play one of the Address Groups. For example, closed and open hi-hats could be stored in the same bank where the closed hi-hat would be played up to one velocity level and above it the open hi-hat would take over. This feature can effectively double the number of sounds available at any one time.

A contentious point, I know, but I was pleased to find a built-in arpeggiator on the S220. Selectable tempo, mode (up, down, up/down or random), range (1-3 octaves), repeats (1-16 times) and decay (nice touch) all go towards making this a useful feature. The arpeggiator can be synchronised internally or to an external source.

Moving on to MIDI, the 220's implementation is quite comprehensive: separate MIDI channels are assignable for each bank in the Multi Modes, and a channel offset feature permits the setting of non-contiguous channels - for example, Bank A can be set to channel 3, Bank B to channel 7 and so on. MIDI Mono Mode also has a place in the picture, however a maximum of only eight voices can be played at one time and the channel assignment in this case must be sequential (1-8, 2-9 and so on). A separate channel can be assigned for global control changes if you like.

The S220 can receive and transmit a wide range of MIDI messages such as Volume, Balance, Registered Parameter and System Exclusive messages, so some pretty powerful programming can be done from the front seat of your sequencer. Program Change messages 1-28 allow access to the 11 structures as well as the on/off of the Detune, Delay and Dual modes. Aftertouch is now recognised and can be assigned to control the output level or balance of the individual outputs and can also be assigned to control the amount of detune. The S220 can receive Note On/Off, Modulation, Pitch-bend, Hold, Volume and Aftertouch separately for each channel in both Multi and Mono Modes.

Little could be easier than sampling on the S220. Separate mic/line inputs and a switchable limiter help keep the distortion problem to a minimum and the 16-bit DAC at the output ensures crystal clear playback of samples. The auto-looping feature is a real blessing and, if you don't like the computer's choice of loops, there is always the manual-looping mode.

The only real problem I had with the instrument was with the Quick Disks which it uses to store information. They don't store a whole lot of data (though you can store performance information as well as sampled sounds) and they're not readily available outside the music shops. But that minor point aside, I'd say that Roland have a good runner in the S220.

Price £975 including VAT

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