Paul White and a new Dutch product that enables digitally stored sounds to be replayed manually or by means of a trigger signal from a drum machine, a computer, or even a microphone.

The most popular current electronic music buzzwords must surely be 'digital' and 'sampling', and both of these apply to the Digisound circuitry. Basically, a read only memory (or ROM) chip is programmed with a short burst of 'real' sound which can be regurgitated on demand by applying a trigger pulse to the circuit.

As it is only cost effective to store relatively short bursts of sound by this method, its application is generally limited to reproducing percussive effects, and it is in this field that the Digisound modules are designed to be used.

Each Digisound module contains one percussive sound which may be triggered by means of the built-in switch, a trigger pulse from a rhythm machine or a piezo-electric microphone. Although the voice module is interchangeable, achieving this requires an inordinate amount of dismantling, and I would imagine that most units would be returned to the distributors if this service is ever needed.

The units require an unstabilised power supply capable of delivering a minimum of ±18 volts and a maximum of ±24 volts and, although the current requirements are not stated, I would estimate that it would be in the order of 150ma per module. Two power supplies are manufactured by TED for this purpose, the DG2 being capable of powering two units and the DG10 of powering ten.

Currently available voicings include both conventional drum kit and Simmons sounds, and more sounds are expected to be available later in the year.

Construction

Housed in a steel box 240mm x 120mm x 45mm, the Digisound is singularly flat (much like its country of origin). The power in and power link connectors are three-pin DIN sockets, whilst both trigger in and audio out sockets are quarter-inch mono jacks.

There are three rotary controls for pitch, trigger sensitivity and output level, in addition to the pushbutton which permits direct manual triggering.

Internal construction is fairly conventional, being based on fibreglass PCBs, but the sound module, or 'DSBB Hart' as it is called, is not just a standard EPROM but a plastic encapsulated circuit with special connectors. This is used ostensibly to increase reliability (the Hart is guaranteed for eight years), but I suspect it has more to do with industrial security, it being impossible for anybody to duplicate the Hart programme using an EPROM copier.

The circuitry contains its own voltage regulators, and anti-aliasing filters are provided to prevent the clock frequency appearing at the output.

In Use

The two modules reviewed here were programmed with 'bass drum' and 'Simmons tom' voicings respectively, both of which were of high quality with no perceptible background noise (quoted S/N ratio is 72dB).

Manual triggering by means of the pushswitch worked well, but more unexpectedly, the external trigger facility was found to be particularly versatile, in that it would trigger not only from pulses but also from the analogue voice outputs on a drum machine. I used a Roland TR606 Drumatix that's been modified to produce separate voice outputs, and the Digisound triggered from all these, including the cymbal voice, providing that the accent was not programmed on any of the cymbal beats, otherwise retriggering occurred during the decay period of the cymbal sound.

John Hornby Skewes kindly provided one of Digisound's contact mics, which would normally be used to trigger the modules from conventional drums but can also be used to convert your ironing board into a novel drum synth. This worked very well, though the sensitivity has to be adjusted to optimise reliable triggering, and by taping the mics to your shoes, you can tap dance to the accompaniment of real drum sounds. This opens up new horizons for technically minded buskers who could now actually play the drums just be tapping their feet...

Conclusions

One recommended use of the Digisound system is to trigger the module's sounds from real drums in order to avoid miking up problems. This does work very well but there is no dynamic control over the sounds which may be limiting for music other than disco styles, though on the other hand, it might help to tighten up uneven playing dynamics.

The tuning control works over more than one octave, but at slower settings the sound quality suffers, as the clock frequency is low enough to pass through the output filters. In practice, there is more pitch control than strictly necessary and a good range of usable sounds is available without going to either extreme.

At an RRP of £69.95 per module (not including power supply or contact mike), the Digisounds are undoubtedly good value if only a few are required but, if you're in the market for a full drum kit, there are less expensive, more flexible systems available that not only produce sounds but also offer sequencing and dynamic control. The TED Digisound does what it does exceedingly well, sounds good and is easy to operate. It provides a convenient method of improving the sound of a poor drum kit for live or studio use, and I'm sure it will be readily accepted by the home recording fraternity.

The beauty of the system lies in its flexibility: if you only want a bass drum, you can buy just a bass drum. Perhaps the TED Digisound will mean that your old analogue drum machine isn't obsolete after all...

TED Digisound Modules: D1001-3 £69.95, D9002 2-unit power supply £19.00, D9004 Trigger mic with lead £2.95, D9005 Connector Cable £3.50.

Further information: John Hornby Skewes, (Contact Details).