Casio SA-35

Digital Keyboard

The SA-35 was introduced in 1992 as part of Casio's SA series of small 32-key "SongBank" digital keyboards. It employs fairly basic (and relatively low-resolution) digital PCM samples to produce its sound.

Features

  • 32 medium-sized keys (F to C / 2 octaves + perfect 5th)
  • 4-note main voice polyphony (only 3-note with accompaniment patterns, and 1-note with SongBank tunes)
  • 25 preset tones divided into 5 groups of 5 tones, with 4 variations each (giving 100 tone variations total)
    • keyboard {piano, elec piano, harpsichord, elec organ, celesta}
    • wind {trumpet, brass ens, clarinet, flute, harmonica}
    • string {string ens, violin, cello, elec guitar, elec bass}
    • synth {waw voice, bells, plunk extend, twinkle echo, jumping}
    • s.e. {car horn, ambulance, airplane, telephone, chirp}
  • 24 accompaniment patterns divided into 3 groups of 8 patterns
    • rhythm {8 beat, 16 beat, swing, slow rock, shuffle, march, samba, waltz} (without melodic accompaniment)
    • accomp. {rock, pops, jazz, funk, house, country, latin, classical} (fixed key melodic accompaniment)
    • funny {fanfare, hopper, computer sound, horror, child's play, orient, jungle, comedy}
  • preset tones, rhythms, & songs selected by multiple presses of group buttons
  • volume +/- buttons (5 steps, bit depth reduces grittily as volume decreases)
  • tempo +/- buttons (16 steps)
  • wavetable-based tone generation, using 2 mixed low-resolution looped samples with independent volume and pitch envelopes
  • 10 "SongBank" demo tunes {twinkle twinkle little star; minuet (j.s. bach); oh! susanna; aura lee; lullaby (brahms); home, sweet home; little brown jug; the skaters waltz; jingle bells; when the saints go marching in}
  • melody off function allows you to remove the melody of demo songs
  • lesson function for learning to play the demo SongBank melodies
  • 2 built-in speakers (wired in parallel, not stereo)
  • jacks for adapter & headphones

Trivialities

  • 2 single-sided PCBs using all through-hole components
  • Very simplistic 2-chip design:
    • OKI M6387-16 microcontroller (30-pin shrink DIP)
    • Matsushita AN8053N 1.0W power amplifier (16-pin DIP)
  • crystal-clocked (making it difficult to change clock speed)

This particular example was purchased at a thrift store in Lacombe, Alberta, and features some amusing writing (to anyone with basic knowledge of musical keyboard layout) on the box, as well as stickers on the keys that have since been removed to reveal plastic underneath just slightly whiter than around the stickers.

The keys themselves are slightly larger than those on the other "Casio" of JCS (Realistic Concertmate-500 which is a rebranded SK-1). They also feel somewhat harder to press down. If you play a key slowly, you can feel the silicone pad exert more force as it is being pushed into an "inverted" state, and then less as it "gives way" about halfway through the keypress, and then for the remainder of the keypress, the key requires increasingly more force to move.

Like many electronic keyboards of the 90s, all of the information with regards to tone, pattern, and song settings is set on the top of the unit, with color coding that corresponds to the relevant buttons (eg. yellow for accompaniment patterns).

The volume control on this unit has some interesting characteristics. First of all, it has only 5 settings, selectable by up/down buttons. The steps are somewhat small, and the result is that it cannot play quiet enough for comfortable headphone listening, and it cannot be played via the speakers quiet enough so as not to wake someone sleeping in the adjacent room. It always turns on at full volume, and when the volume is decreased, it appears that it only decreases in sofware, so before the gritty low bit-depth DAC, so turning the volume down adds considerably more "grit" to the sound in the form of quantization noise.

As well, the volume level significantly modulates the speed of certain repeating tone elements, for example the "mandolin ring" on edit 2 of the "elec guitar" tone speeds up quite a bit as the volume is decreased.

As another amusing side-note, although there was no actual owner's manual in the box, there was instead this lovely unused ordering slip for a "Talking Owner's Manual" cassette, as well as the "Never Be Embarassed Electronic Keyboard Play-Along System" which promises quite amazing results if you simply play any of the black keys. Hmm...

Update: As of 12/16/2014, this unit has been exhibiting issues; when certain keys are pressed, it plays two notes at once. This is the kind of effect that would be observed if two keyboard matrix lines were accidentally shorted together, but I've gone over the board many times, and cleaned and re-soldered connections, and there appears to be no such short to be found. For now, I'm assuming it may be an issue with the microcontroller chip itself, which is quite unfortunate, since such a chip is impossible to replace without a donor unit.

It has been used in the S.F.A.T.B.H.S. release Novoful Vyffm in this slightly defective state.

Links

Owner's Manual

Casio SA-35/SA-5 - An excellent page with great amounts of info about small keyboards, including this one.

If you notice any errors or have additional information that you would like to add, please contact me!


Last Updated: 12/16/2014