Yamaha PSS-6, PSS-12

Yamaha PSS-6

mini keyboards with sample sounds & many lovely demos

PSS-12

Yamaha PSS-6

This small keyboard has sample based sound with astonishingly high sound quality and a lot of lovely demos. (Mine contains a sticker "10 OCT 1996", but IC copyright label and embossed case date stamp from 1994.)

The concept of this instrument has many similarities with Casio SA-5. Like the latter it selects its 100 preset sound by multiple presses of 5 group buttons and a 4 variations button. But unlike the SA-5, the Yamaha PSS-6 has no tekkno sounds but only natural instrument samples, and the variations are mainly duet or trio versions of the same preset sound or add echo etc. The rhythms have an optional fixed- key accompaniment (called "jam tracks") that plays pre- programmed chord sequences and can automatically switch the main voice sound all few patterns.

This keyboard has been emulated on MAME.

main features:

32 mini keys (black keys are fragile)
built-in speaker (high quality)
main voice polyphony 2 notes
100 preset sounds divided into 5 groups with each 5 sounds and each 4 variants per sound selected by the "variation" button: {piano, e piano, harpsichord, clavi, e organ | violin, vibraphone, marimba, flute, clarinet | folk guitar, e guitar, banjo, harp, strings | saxophone, harmonica, accordion, trumpet, horn | fantasy, wood bass, e bass, slap bass, piano split}
15 preset "jam track" rhythms {dance, rap, funk, rock, minor blues | rock 'n' roll, r&b, slow rock, jazz blues, fusion | bossa nova, samba, tango, march, waltz} (switch main voice sound all few patterns).
preset sounds & rhythms selected through multiple presses of group buttons
"jam tracks" accompaniment (fixed- key chord sequences, can be switched off)
volume button (7 steps, stepping down & up again)
tempo button (7 steps, stepping down & up again)
"AWM" wavetable sound generator with sounds based on medium resolution samples with partly complex volume envelopes (those e.g. simulate echo) and surprisingly high sound quality (16 bit?).
multi-chip hardware:

CPU= "Yamaha YMW282-F, 9620 ABGB" (80 pin SMD | GEW7S, crystal clocked @ 8 MHz)
ROM= "©1994 Yamaha, XP733A0, M531031B-12, 5132352" (32 pin DIL, 128KB)

15 lovely demo melodies (wonderful complex polyphonic orchestrations)
"minus one" function (mutes melody voice of demos to train playing)

eastereggs:

service mode: Hold the 2 leftmost white keys during power-on to run the test program. Red and green LED will light up. All keys play "e organ" notes without vibrato (which is no preset sound). All panel buttons play sine wave notes. The "voice/ song" button lights alternatingly both LEDs when held. The volume always stays at maximum. Press leftmost + rightmost white key to exit.

echo speed controllable by tempo button.

notes:

The Yamaha PSS-6 was likely intended as competitor to the Casio SA series, but in opposite to it the tone quality of the PSS-6 is astonishingly high and sounds almost too good for such a toy- like mini keyboard - it would have been even enough for a cheap fullsize General MIDI keyboard, thus it is badly understandable why Yamaha omitted a sound output jack. The CPU uses an external ROM ©1994 by Yamaha. I first thought the higher polyphony of the PSS-12 can be also added as a matrix easteregg by installing a diode somewhere, but the different ROM makes this unlikely, although PSS-12 seems to use more of its CPU pins. (I haven't analyzed the hardware further.)

The preset sounds are selected by pressing the button of the desired sound group multiple (up to 5) times, which always plays the currently selected sound as a hint. Then the 4 variants of that sound can be tried by pressing "variation" multiple times, which also each time plays the current sound. (They don't play sounds during rhythm.) The "volume" and "tempo" buttons play always a low or high knock to indicate whether they are stepping down or up. Rhythms and demos are selected with the same group buttons like the main voice preset sounds. The group buttons are switched by the "voice/ song" button, that indicates its current mode by lighting a red or a green LED (that also flashes as tempo LED during rhythm). Any selected sound or demo starts immediately. This user interface concept is very intuitive, but it also disturbs live performance.

The main voice preset sounds are based on medium resolution samples and thus behave static, but they sound very clean and in no way noisy or lo-fi. Unfortunately they are strictly focussed on natural instrument samples those sound very establishment and don't include any remotely extreme tekkno sounds. (For tekkno try a Yamaha PSS-7 instead.) The best thing it can do is soft pad timbres. Like with Casio SA-35, each preset has 4 variations, but here the variations are typically just duet or trio or other fixed chord versions of that preset sound (these variations play only monophonic), or a different instrument sample is selected. Some add a dose of reverb or chorus, and a simple repeating echo is already the most avantgardistic effect of this instrument - at least its speed can be adjusted with the tempo button. The "fantasy" sound is here simply a sort of mellow vibraphone (on Casio VL-1 it was a creaky synth organ tone with vibrato, while on Casio SA series "fantasy" sound like a sitar). There are also a few key split sounds (bass + others) and layer sounds (piano + strings).

(The full sound set list can be found in the manual of this instrument, downloadable on the Yamaha Manual Library site.)

The rhythms use medium resolution samples of acoustic percussion. They select their own default tempo and normally start with an automatic fixed- key accompaniment called "jam track", that plays a pre- programmed chord sequence (like a demo without melody voice) and also automatically select and switch the main voice preset sound. This behaviour can be disabled by manually selecting a preset sound after the rhythm is started. With the "minus one" button the accompaniment can be muted and re- enabled while the rhythm stays on.

The instrument has a song bank of 15 wonderful orchestrated polyphonic demo melodies:

Original Song 1 [fusion]
Original Song 2 [latin fusion]
Original Song 3 [slow latin fusion]
Deck the Halls
Sur Le Pont d'Avignon
Beautiful Dreamer
Londonderry Air
Symphony #40
La Cucaracha
House of the Rising Sun
Silent Night
Oh! Susanna
Song of Joy
O. Vrenelli
Troika [one of the Atari Tetris arcade tunes, jazz version]

With the "minus one" button the main voice can be muted to improvise to the demos. All demos are quite long and complex arranged. The 3 "Original Song" pieces are jazzy funk/ fusion musics. Also "Deck the Halls", "Londonderry Air", "Symphony #40", "Troika" are in a dreamy blues/ jazz style that sounds very mellow and muzak- like - just like out of a senior's home. Apparently Japanese like such stuff, because I also found it in Japanese videogame highscore musics and Anime movies.

Yamaha PSS-12

This keyboard from 1994 (embossed case date) is the midsize version of the Yamaha PSS-6. The most important difference is its very high polyphony, but some preset sounds were changed and here include a keyboard percussion mode.

This keyboard has been emulated on MAME.

different main features:

32 midsize keys
2 built-in speakers (high quality, mono)
main voice polyphony >12 notes (8 with accompaniment, only 1 with duet/trio preset sound variations)
different 100 preset sounds, divided into 5 groups with each 5 sounds and each 4 variants per sound selected by the "variation" button: {piano, e piano, piano ens, harpsichord, clavi | organ, guitar, e guitar, jazz guitar, 12str guitar | banjo, harp, strings, violin, vibraphone | marimba, flute, saxophon, accordion, trumpet | brass ens, fantasy, wood bass, e bass, percussion}
volume +/- buttons (16 steps)
tempo +/- buttons (51 steps)
"one touch setting" button
multi-chip hardware:

CPU= "Yamaha YMW282-F, 9423 GEDB"" (80 pin SMD | GEW7S)
different ROM "©1994 Yamaha, XP598A0, M532031B-04, 4392352" (32 pin DIL, 256KB)

headphones/ aux jack

eastereggs:

service mode: Hold the 2 rightmost keys during power-on to run the test program. All LEDs will light up. All keys play "organ" variation 1 notes without vibrato (which is no preset sound). All panel buttons play sine wave notes and unlight LEDs. Buttons with LED light them when held; the "voice/ song" button lights alternatingly red and green. The volume always stays at maximum. Press leftmost + rightmost white key to exit.

echo speed controllable by tempo button.

notes:

Unlike PSS-6, the tempo here can be adjusted much finer in 51 steps, but it resets to default when rhythm is started or changed. The additional "one touch setting" button here automatically switches the main voice preset sound when the "jam tracks" accompaniment patterns change. The PCB here is double sided and seems to use more CPU pins. The amp has noticeable static noise. I saw schematics photos mentioning a 2M ROM, which apparently means 2Mbit (256KB) i.e. twice the PSS-6 capacity.

The direct successor of the PSS-6 was the pretty Yamaha PSS-7, which has way lower sample resolution and features also great granular tekkno sounds; its midsize variant is the PSS-14. A technically close relative of the PSS-12 is the Yamaha PSS-31 (similar sounds and hardware).

*removal of these screws voids warranty...*

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