Casio MT-30 (1980)
A compact 49-key polyphonic home keyboard with fixed presets and onboard recorder, among Casio's earliest midsize instruments.
Overview
The Casio MT-30 is a polyphonic midsize keyboard released in 1980. It was one of Casio's first entries in the home keyboard market. It has 49 mini keys with no touch sensitivity or aftertouch, and 22 preset voices, from electric piano and strings to brass and novelty fuzz tones. Synthesis is limited, but it has a built-in recorder and an on-board learning system. It has no rhythm, no accompaniment and no MIDI. Basic controls are white keyboard keys and a mode switch, including vibrato and sustain toggles. The nearly identical MT-31 succeeded it and mirrored the internal layout - most notably, the speaker moved to the left side.
Specifications
| Number of keys | 49 |
| Key size | Mini keys (synth/organ style) |
| Touch sensitivity | no |
| Aftertouch | no |
| Polyphony | 8 |
| Number of voices/presets | 22 presets preferred over pianoandsynth.com |
| Preset Sound list | electric piano, banjo, guitar, harpsichord, xylophone, celesta, glockenspiel, organ, accordion, pipe organ, oriental pipe, brass, cello, synthe fuzz, violin, trumpet, funny fuzz, st. ensemble, clarinet, flute, recorder, folk flute |
| Rhythm | no |
| Accompaniment | no |
| Sound generation | timbres based on 2 mixed stair waveform tones with different digital envelopes those are differently low pass filtered through capacitors. |
| Piano sounds | yes |
| Real world sounds | yes |
| Sounds editable | no |
| Recorder/Sequencer | yes |
| Tutorials/on-board learning system | yes |
| MIDI | no |
| USB | no |
| Tablet connectivity | no |
| Power | AC Power: yes, Batteries: yes [sources disagree] |
| Speakers | yes |
| Audio Out | yes |
| Audio In | no |
| Audio Jacks | jacks for AC-adapter, headphone and cinch sound output |
| Built-in speaker description | built-in speaker (with a slightly unpleasant midrange resonance) |
| Sustain Pedal | no |
| Soft Pedal | no |
| Expression Pedal | no |
| Main chips | CPU= 'NEC D775G , E11046' (64 pins with strange zigzag layout) DAC hybrid= 'EXK SIOL0025C' (11 pin SIL) amp-IC= 'LA4137' (14 pin DIL) |
| Controls | selected by white keyboard keys + mode switch, useless 'tone memory' 4 step switch to assign 4 of the preset sounds for quick access, vibrato & sustain switch |
Design
There is a woodgrain version, possibly labeled MT-30W. Inside is a heavy sheet metal frame that supports the keys. The slide switches and potentiometers are screwed to that frame rather than just mounted on the PCB. The black keys have plain sides, unlike later Casio midsize models. The loudspeaker compartment is split horizontally by a pressboard wall and damped with foam rubber mats. The main PCB is small and fills only about one-third of the case. Sound comes from two mixed stair waveform tones with digital envelopes and low-pass filtering via capacitors.
Context
The MT-30 was the first polyphonic midsize keyboard with multiple sounds made by Casio. It belongs to the MT family and was followed directly by the MT-31, which is nearly a mirror image - most visibly, the speaker moved to the left side. Casio was competing in a market increasingly shaped by Yamaha's presence in electronic keyboards.
Reception & Use
The MT-30's sounds are described as bright. Most presets are considered unconvincing imitations of acoustic instruments, except the flute-like tones, which fare better. During trills with sustain, each new note uses a separate sound channel. That creates a phasing effect and a volume buildup. The bass range also tends to overpower high notes, because of muffling filters in the sound design.
Collectibility & Maintenance
Opening the MT-30 risks damaging the snap-in plastic tabs that secure the case. Cracked tabs and scratched rims are common. Documented modifications include adding a polarity protection diode and correcting the power jack polarity. Hidden expansion possibilities include adding switches for mild vibrato, faster vibrato, octave down, sustain, hold, and spread tone scale, and enabling 12 additional lower note keys.
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