Casiotone 201

the world first Casio keyboard
(unusual semi- analogue sound)

This quite heavy wooden thing from 1980 was the world first music keyboard ever created by Casio and constitutes basically also the world first digital sound bank instrument because it had already 29 partly unusual preset sounds those are selected through the white keyboard keys. The "tone" switch offers 2 envelope variants for each sound and thus doubles the number of presets to 58 sound in total. (But this old instrument had no rhythm yet.)

All sounds are based on 2 mixed multipulse squarewaves with independent digital envelopes those are sent through different capacitor filters. The resulting timbres remind to C64 or historical videogame musics. Casio called this system Consonant Vowel synthesis. (For more info on this technology also see here.)

main features:

49 fullsize keys
built-in speaker (with sufficient bass but some upper midrange resonance)
polyphony 8 notes
29 preset sounds {Elec. Piano/ Cello, Elec. Guitar, Koto, Banjo, Elec. Clavichord, Harp 1, Ukulele, Harp 2, Glockenspiel, Lyre, Bell Lyra, Celesta, Harpsichord 1 & 2, Organ 1 & 2, Fluegelhorn, Trumpet, Pipe Organ 1 & 2, Viola/ Thrombone, Cello, Brass, Wood 1 & 2, Flute, Clarinet, Violin, WA WA} selected by white keyboard keys + mode switch
useless "tone memory" 4 step switch to assign 4 of the preset sounds for quick access
vibrato switch
no sustain switch (only pedal input)
"tone" switch (selects between 2 envelope variations for each sound and thus doubles the sound palette)
timbres based on 2 mixed multipulse squarewave tones with different digital envelopes those are differently low pass filtered through capacitors. According to Robin Whittle's bulletin "Modifying the Casiotone Instruments" from 1981, both CPUs run independently in sync with each other and do the same, with the only difference that they contain each a different set of preset sounds in their internal ROM. This way any preset sound of the instrument is layered from the differently filtered sound outputs of both CPUs.
CPUs "NEC D771G, E04036" and "NEC D772G, E02026" (both 64 pins with strange zigzag layout)
jacks for mains cord, aux. in, line out, tape echo device ("from", "to"), sustain & foot volume pedals

eastereggs:

when instead of a white a black key is pressed in sound selection mode, the instrument plays no sound at all.
The sounds "Harp 2"(?), "Organ 1", "WA WA" can be also selected through the 3 leftmost black keys.

notes:

Very bizarre is that the preset sound names are not printed on the wood case but only on a loose transparent overlay of flimsy plastic foil while on the case itself stand only sound numbers. Possibly Casio intended to make it easier to release local instrument versions with foreign language sound names, although my German version has English names. But the control panel writing is directly printed in English on the wood case despite it is also protected by an unprinted thin overlay. My theory is that apparently the chips were not finished yet when the wooden case was manufactured, thus the case manufacturer could not know the final set of preset sound names and thus only printed numbers on it. The flimsy overlays look preliminary and may easily tear when carried wrongly. (At least my specimen has an imitation leather carry bag.)

Sound names are only on the overlay - the numbers on the wood case.

Also bizarre is that as well the fullsize Casiotone 201 as the Casio MT-30 were Casio's only "lefty" keyboards, because as well the control panel of the Casiotone 201 as the speaker and power switch of the MT-30 were placed to the right hand of the keyboard, while already with their very similar successors Casiotone 202 and MT-31 and all later keyboards the panel next to the keys was placed to the left. (Some people also call this instrument CT-201, but the "CT" in Casio model names was introduced later.)

The case is a solid wood construction.

The power supply is below the control panel.

The case is made from genuine wood (coated with mahogany imitation woodgrain) and the keyboard frame from heavy sheet metal. Unlike many other old instruments, the key switches here employ already silicone rubber contacts. Below the keyboard are 2 relatively large main PCBs; the left one contains the main digital stuff (including the large ICs D771G and D772G) and various logic ICs, while the right one seems to contain mainly analogue circuits with a lot of discrete components, op-amps(?), logic ICs and the power amplifier. For a digital keyboard without rhythm section the complexity of the hardware is quite impressive. The power supply is below the control panel to the right. The protruding switches are no good design and may easily crack off during transport of the heavy instrument; my "tone memory" switch was already damaged and thus failed to lock and made bad contact, which was especially noticeable in the tone memory "set" mode (keys didn't respond when switch open). I fixed this by pressing the bottom PCB of the slide switch back into place; it's still a little loose but works now.

Like with Casio MT-60 and CT-410V the sounds consist of 2 mixed multipulse squarewave suboscillators with different pulse patterns and different digital volume envelopes, those are (depending on the preset) muffled by different filter capacitors. But while the latter use sophisticated envelope controls, the Casiotone 201 and MT-30 use for its 2 suboscillators only very simple attack- decay envelopes. In the bass range many sounds turn into a more or less buzzy, sonorous purring drone, which is a characteristic style element of squarewave based instruments. These basses can resemble some of the famous POKEY sound effects on Atari XL homecomputers and are very different from the gradually duller and duller growing sine wave bass behaviour of average Yamaha FM keyboard sounds. (For further technical details about this hardware family also see here.)

Like the later MT-60, most sounds are rather bright and use apparently only a few different filter settings. But in comparison to the MT-60 most sound preset of the MT-30 are rather boring attempts of imitating acoustic instruments, those as usual with squarewave instruments don't sound natural anyway (except with flute- like instruments), and by the lack of complex envelopes there are also no gimmicks like ringing mandolins. But due to the 2 suboscillators and filters they sound at least less plain than e.g. the timbres of a Letron MC-3. Due to the muffling filters, the bass range of various sound presets is too loud in comparison to simultaneous high notes.

The sounds are not bad, although most of them have rather little to do with their names. When not otherwise mention, I describe here the versions with "tone" switch set to 1. Interesting is that Casio named the only piano sound here "Elec. Piano" - likely because they knew that this hardware can not imitate a piano well - however it sounds more like a sonorous e-bass or tuba. The same sound is used as "cello" with a different envelope when the "tone" switch is on 2, despite there is a dedicated "cello" preset. The "Elec. Guitar" is a little brassy and also the "Koto" sounds similar. The "Banjo" sounds brassy too and has a long sustain phase that fades silent with rather low volume. The "Elec. Clavichord" is almost the same, only with a louder sustain phase. The "Harp 1" has a too long attack phase and thus doesn't sound percussive enough. The "Harp 2" resembles rather a dull reed organ that slowly fades silent. The "Ukulele" otherwise sounds like a harp. The "Glockenspiel" is not percussive enough and also rather a fading organ tone. The "Lyre" sounds ok (small harp) and also the "Bell Lyre" sounds harp- like. The "Celesta" is more a Rhodes piano and not very percussive. The "Harpsichord 1" and "2" sound quite ok and contain a metallic (aliasing?) overtone. "Organ 1" is a multipulse squarewave timbre and resembles a dull and bassy reed organ. "Organ 2" is a less dull variant of it. "Fluegelhorn" is a brass timbre (like intended) with a little buzzy bass range. The "trumpet" is rather dull and could be also a dull reed organ timbre. Both "Pipe Organ" timbres are quite bright, like metal organ pipes. The 2nd one is very bright and contains a chorus effect (tone=2 =>brighter without chorus). The "Viola" contains a chorus effect (which vibrato gets faster during higher notes) and with tone=2 it is duller and called "Thrombone". The "Cello" sounds static and could be also a brass timbre. The "Brass" is quite dull and resembles more a dull reed organ timbre. Both "Wood" timbres likely shall be wooden pipe organ timbres and sound quite ok. "Flute" and "Clarinet" sound quite realistic. The "Violin" has a rather slow attack phase is too dull and could be also some kind of flute although it fades silent after a while. The "WA WA" is a sweetish sort-of human voice made from 2 crossfading tones singing "wah" (and slowly fades silent); high notes rather resemble a flute. When not otherwise mentioned, the "tone" switch varies most sounds only gradually (e.g. duller or brighter or with/ without chorus).

When sustain is off, all sounds stop almost immediately after releasing the key, which is particularly annoying since this instrument has no sustain switch and can activate sustain only by pedal. The sound presets itself also contain neither vibrato nor tremolo (but some a chorus, likely implemented by detuning on of both subvoices). Unfortunately even with sustain here a trilled note does not occupy new sound channels which on other ancient Casio keyboards (e.g. MT-30) produced a great phasing sound and volume increase effect.

To select sound presets, the "mode" switch has to be moved from "play" to "set", which will also assign the selected sound to the current position of the "tone memory" switch. The sounds are then selected by white keyboard keys. Very interesting is that the selected sound is played as a hint during the selection key press, but only when the key is held down longer than about 0.2s. (It's a pity that this trick is not used on average toy keyboards, because the delay would make it possible to rapidly select OBS sounds during live performance without hearing the selected sound, and despite easily test the sounds by pressing the buttons slightly longer.) When the "mode" switch is set back to "play", the keyboard behaves normal again (and the "tone memory" switch can select between 4 of these sound presets during play). After power on, the 4 "tone memories" contain the sound presets {Elec. Piano/ Cello, Harp 2, Organ 1, WA WA}. Only the white keys are used to select sounds; possibly an external ROM chip with additional sounds for the black keys was planned, because pressing most black keys apparently selects here an empty sound because it mutes the keyboard. Otherwise on the leftmost 3 black keys are the preset timbres "Harp 2", "Organ 1", "WA WA", those correspond to 3 of the default sounds. Strange is that this "Harp 2" is a little quieter than the normal "Harp 2" sound from the white key number 8. In practise the "tone memory" switch is rather useless, and it also makes no good realtime sound effect since it responds with a delay of about 0.25s.

The direct successor of this instrument was the Casiotone 202 from 1981, which sound bank had even 49 sounds at a time where other preset keyboards still had maximum about 12 or 20 preset sounds. But this one had no selectable envelopes anymore (which basically doubled the number of sounds), a great feature that was re- introduced only later with the Casio MT-65 hardware class (see CT-410V). A technically much simplified single chip successor of the Casiotone 201 hardware was the Casio MT-30. The first Casio keyboard with accompaniment was the Casiotone 401.

*removal of these screws voids warranty...*

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