Yamaha RX-21 Digital Drum Machine, 1985, made in Japan

Link: muzines | synthmanuals

The giant Nippon Gakki company have just released the very cheapest drum-machine; it's designed to sit comfortably at the bottom end of the market. They now make RX-11, RX-15 and RX-21 all with basically the same intrinsic, digitally sampled drum sounds, but with different control functions. (For example, the '21', like the '15' has only a stereo output, but you get what you pay for in drum machines. Yamaha intend you to adjust the volumes between the instruments very carefully, so it can be very convincing.)

This machine has nine different voices, and 40 different pre-set patterns which are held in ROM. These can form the basis of your songs as they are, or you can alter them as much as you like and enter them into RAM (without destroying them). They'll now play in the normal way. Yamaha also thoughtfully provide several 'tacets' to spice up your patterns as well as 56 user programmable memories. RX-21 has a capacity for 100 patterns and, as with most state of the art drum machines, to avoid running short of memory you may always dump to cassette and load the digital info back in again when you need to. As you are no doubt aware, you need to join several patterns together to construct a whole song. RX-21 has this facility, of course, and will hold up to four songs with a maximum of 512 parts each.

The machine itself is wedge shaped and measures 13½" x 8" x 2" at its thickest. It's a plain, hi-tech sort of design with functional, though not over-large, rubber press buttons. To the very left of the top face is the LCD window which, as per usual, shows all the information you need to program in real or step time, and also to build patterns. Many of the functions are accomplished by pressing buttons more than once, but we'll get to this later.

All the voice buttons are set along the bottom of the machine in two rows of seven. The first two are coloured blue and show Tempo in BPMs and Level for each voice. (Both of these functions may be adjusted with the No and Yes buttons. One adds numbers while the other subtracts). Next to these we have our Accent button coloured green; when this is pressed whilst programming a volume increase will result for the voice in question. Next we have snare drum, then toms 1, 2, and 3, then bass drum, hi-hat open, hi hat closed, cymbal and finally claps. The last two buttons operate start and stop/continue. Above these are set a dozen smaller rubber buttons. These relate directly to Pattern recording, Play and Beat (ie Quantise). Next to these we find Real Time Write and Step Time Write, then Song Play and Write, then Clear and Repeat, then Cassette and Insert and finally MIDI and Delete. To the right of these are the keypad numbers in a row from 0 to 9 and then we have those Increase and Decrease buttons and that's it. Because there's only the Stereo outputs (left and right), there's not an awful lot going on round the back. There's an On/Off switch, a DC9V-12V socket for the power pack (which is supplied), a headphone socket and three DIN sockets. One for Cassette In and Out and the others for MIDI.