Kay Memory Rhythm Machine
The Kay Memory Rhythm Machine, distributed by British Music Strings Limited, was one of the new products featured at the London Music Trade Show in August.
It is programmable with 240 beats worth of storage capacity, the memory being split into two sections; A and B. Each section is further split into six rhythms of 16 steps and two rhythms of 12 steps for 4/4 and 3/4 timings respectively. Up to four instruments can be triggered on each step, representing Bass Drum, Snare, Hi-Hat and Cymbal.
The case is formed from pressed steel covered in textured plastic. A small panel at the back can be removed to allow the four HP7 batteries to be replaced when required. Power can be supplied via an optional 6V adaptor although the batteries are required to retain the memory contents when the unit is switched off.
The machine comes to life when a jack is connected to the output socket and the volume control switch is on. A stored rhythm can be played by selecting the desired number on the Rhythm Select switch, setting Variation and pressing the Start button. The rhythm will always start on the first beat in the bar no matter where it is stopped. An optional footswitch can be connected to control the start and stop functions remotely provided that it is a locking push on/push off type.
The Variation switch can be set to play A or B (16 or 12 steps each), AB (32 or 24 steps) and Fill-In. In this mode you can select 4 (3A's then a B), 8 (7A's then a B), or 16 (15A's then a B). This means that you can give the rhythm a slightly more 'human' feel with interesting breaks or fills.
Now to the more interesting bit! Programming is accomplished in a way analogous to multi-track recording. Each instrument being recorded one at a time in play/rest fashion.
Setting the Mode switch to 'Write' puts the unit into its programming mode. The down-beat LED (situated beside the Tempo control) comes on to indicate the first step in the rhythm. Select the rhythm number and variation; A or B for 16 or 12 steps or AB for 32 or 24 steps, and the Sound; Bass Drum, Snare, Hi-Hat or Cymbal.
The rhythm can now be entered step by step using the start and stop buttons as play and rest for each sound until the required number of steps have been recorded. After the 16th or 12th beat the LED will come on again to indicate the first step.
Having entered the rhythm it can be played by selecting 'play' and Start. The only way to edit an individual track, however, is to re-enter it from the first beat.
The machine has two trigger outputs; Clock and SQ. These are provided for interfacing with a sequencer, computer or another drum machine.
The Clock output, as the name suggests, is derived from the internal clock and provides a gate, with a positive-going edge, of approximately 6V (supply voltage). The SQ output is in fact the Hi-Hat trigger and connecting a jack to this socket disconnects the trigger to the Hi-Hat generator. This trigger does not have the same drive capability as the Clock output and probably would need to be buffered for use with external units. However, this is a useful facility to have for triggering external sounds (e.g. E&MM's Syntom or Synwave) during a rhythm.
As this was an engineering prototype it is not fair to comment on the internal construction. However, the circuit is based around a Toshiba IC which contains all the memory and decoding circuits. The clock and counter are provided by two other CMOS devices. Instrument voices are generated in the usual analogue fashion with Twin-T networks for Bass and Snare drum and Zener generated noise, filtered using a small inductor, for Snare, Hi-Hat and Cymbal noise.
The unit is very neat with clear and functional labelling, however, the steel case provided for the prototype had some very sharp metalwork protruding, but BMS assure us that this will be amended in production models.
The inclusion of the interface outputs is a welcome addition to this type of machine but a clock input would have been useful for synchronizing with a click track trigger.
Probably the most important consideration when buying a drum machine, though, is the quality of the sounds. Although these are not 'real-drum' sounds, they do provide an adequate simulation. The Tone control is useful here for adjusting the high frequency content of the Cymbal and Hi-Hat.
From the control point of view the unit is simple to programme and allows a versatile range of playing options with the Fill-In selection.
The most exciting thing about a programmable rhythm machine is the challenge of creating new and interesting drum patterns. For £75 (less if you shop around) you have the sounds and the means to control them, so the rest is up to you.
Review by Kenneth McAlpine
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