Elta KE-491

digital lo-fi keyboard with simple synth, programmable rhythm, play teaching & MIDI- out

This stylish looking silver midsize tablehooter has MIDI- out, programmable rhythm, play teaching through an LCD and even a simple synthesizer, but the main voice is only a thin and glassy sounding My Music Center variant with strong DAC aliasing distortion in high notes.

The concept and flaws of this instrument remind much to the First Austria MC-36 although both sound quite different. The rhythms, accompaniment and many behaviour details have strong similarities with the toy keyboard K-Mark WP9019A1 although the latter had even a more sophisticated main voice. The only 4 note polyphonic sound generator of the KE-491 seems to be a slightly improved My Music Center variant those timbres contain much digital noise, a dose of chorus and noticeable zipper noise. Despite the 30 preset sound names even appear in the LCD as 4 letter abbreviations and the sound generator tries very hard to find its best matching timbre (which is no matter of course with such tablehooters), the result sounds thin, cold and noisy and doesn't really satisfy the ear. Even for fans of the My Music Center hardware family it is IMO not the best sounding variant, because it yells too harsh and thin and wannabe hifi, but at least it is the only known My Music Center successor with a built-in synthesizer and has well responding keys, thus it may become a kind of holy grail for some of you.

The simple synth mixes any 2 of the 30 preset sound waveforms and sends the result through a volume envelope. Unfortunately there are only 6 boring preset envelopes of natural instruments available, the 2 subvoices can not be set to different envelopes and also the volume ratio of both oscillators can not be changed, which makes the result always sound very establishment. It can e.g. create nicely sonorous pipe- and reed organ timbres, but it has nothing to do with the dinosaur, whistle or motorcycle sound icons those advertise the synth feature on the box. At least there is an effect button to add either vibrato, echo or detuned chorus to any main voice sound. The digital ice- age appeal of the sounds partly reminds to the Hohner KS 49 midi synth, although the latter is much more versatile and based on different technology.

But also the digitalistic operating concept of the KE-491 is awkward and not remotely OBS; despite there are no menues, all sounds and rhythms are selected through a dial (named 'twirling wheel' in the Engrish manual) and have to be confirmed with a beeping 'enter' button, and you can not even select a different preset sound without stopping the rhythm. Also the 5 memory settings for user programmed synth sounds and 6 for rhythms don't help here. The percussion is made from medium resolution samples and the 10 rhythms play too loud in ratio to their accompaniment. Despite there is a fingered chord mode, it accepts only establishment chords, turns the main voice monophonic and there is no manual chord mode at all. Most of the 10 accompaniments sound like reggae. The right keyboard section can be switched into keyboard drumkit mode. Also the play training feature is very questionable, because the 10 demo songs used by it contain so many own flaws that it is hard to understand how anybody should learn correct keyboard play from them. But at least the accompaniment loops from the one key play mode can be abused for tekkno.

main features:

49 midsize keys
2 built-in 10cm speakers (stereo, sound thin and bassless with unpleasant midrange resonance)
main voice polyphony 4 notes (only 3 with rhythm, 1 with accompaniment)
30 preset sounds {piano, electric piano, harpsichord, celeste, organ, bell, music box 1..2, accordion, nylon guitar, electric guitar, jazz guitar, banjo, e. bass, violin, cello, string 1..2, harp, trumpet, tuba, french horn, brass, synthetic brass, flute, oboe, clarinet, alto saxophone, whistle, pipe} (selected through dial + 'enter' button)
10 preset rhythms {disco, dance, funk, ballad, fussion, pop bossa, cha - cha, slow waltz, march, polka)
additionally 5 user preset sounds & 6 user preset rhythms (selected like normal ones)
dial to select sounds, rhythms, demo songs
volume +/- buttons (16 steps)
tempo +/- buttons (32 steps)
transpose +/- buttons (13 semitone steps (-6..+6))
single finger & fingered chord accompaniment (only standard chords, no manual chord mode)
effect button {vibrato, echo, 'reverb' = detuned chorus}
keyboard drumkit mode {base, snare, close hihat, cymbal, tom, cowbell, hand clap, shaker}
rhythm fill-in button
primitive sequencer (monophonic record/ play of 40 notes, no edit, sequence is deleted when other functions are used)
programmable rhythm (monophonic, 5 user patterns)
simple synthesizer (2 preset waveforms + 1 volume envelope, 5 user sounds)
LCD display (shows tempo, selected sound/ rhythm/ song, keyboard keys & finger placement, synth parameters etc.)
sound generator resembles My Music Center. It has only very simple volume envelopes (attack- decay?) with noticeable zipper noise. High notes have unpleasant aliasing noise by too low DAC output frequency. Percussion is made from unlooped medium resolution samples (with audible end click).
multi- chip hardware:

CPU= "CIL-3749, REV. II, YKF9518-2, 1" (44 pin COB)
LCD controller= "CIL-3749/HT-, YKF965, A, 1" (68 pin COB)
flash memory?= "HT93LC66-B, ALI5K0661-3" (8 pin SMD, The instrument holds user data without battery. The manual mentions "MEMORIES: 4 Kbit".)

learning feature & one key play (displays keys & finger position of right hand on the LCD)
10 demos (also used for learning feature)
auto- power off (resets everything after a key press)
jacks for AC- adapter, microphone, line out, MIDI- out

eastereggs:

When a user sound is selected and the instrument is switched into MIDI mode, then the 2nd subvoice of played notes will be muted semi- randomly at about every 2nd pressed key. The phenomenon does not occur so long the vibrato or echo effect is enabled.

notes:

The electronics of this instrument looks astonishingly well constructed; the ribbon cables have plug connectors and there is no cable mess at all, which is quite unusual for such a poor sounding tablehooter. The case shape and PCB design strongly resemble the Superb Sound EK-905, while the horizontal lines and groves in the silver case also remind to the stylish Sankai 01870K. Also the preset sound names are correct; only some keyboard drumkit icons are slightly wrong. During rhythm there is a horizontal walking light of 1 red and 3 green LEDs, which reminds to the small K-Mark WP9019A1 that has many rhythms and behaviour details common with it. Annoying is that the auto- power off resets the entire instrument with a buzzy beep; after a key press it comes up with a cold start at quite high volume. All buttons play a blip sound that disturbs live performance, and the stubborn user interface also has various other severe flaws those remind to Yamaha PSS-31. E.g. you can not select another preset sound without stopping the rhythm; any rhythms, sounds and demo songs are selected with a dial (showing the abbreviated name in the LCD) and confirmed with the 'enter' button ("beep!"...). But to switch the dial among {voice, song, rhythm, MIDI} mode you have to turn a rotary switch that always stops running rhythm, and because you can only start a rhythm in 'rhythm' mode, there is no chance to use it so long you are in 'voice' (i.e. preset sound select) mode. The sound of the Elta KE-491 is unpleasantly thin, noisy and cold, but I am not sure if this is only an analogue flaw by a poorly designed (oscillating) power amplifier; it also distorts a bit and at higher volume and there is always fairly loud static noise in the background. Perhaps the flaw can be fixed, which would turn the KE-491 into a nicely versatile lo-fi instrument.

Astonishing is that the instrument even holds user programmed sound, rhythm and sequencer data without battery; the manual mentions "MEMORIES: 4 Kbit", which may refer to a flash memory chip. (I can only hope that the internal ROM software is not also stored inside that chip, because flash EEPROM chips are infamous to loose their data after only 1 or 2 decades and can easily become corrupted by a program crash. Thus be very careful with circuit bending attempts on this instrument.) Strange is also that the manual claims polyphony to be 8 channels, while in reality it has only 4; either they referred to the internal count of subvoices (each main voice sound employs 2 subvoices for chorus), or there is an easteregg hidden somewhere to disable the chorus effect in favour for twice the polyphony. (I haven't analyzed the hardware closer yet.)

The preset sounds are made from each a static waveform with simple volume envelope and a dose of chorus. Despite the sound generator seems to be very similar to My Music Center (see there), the timbres and envelope durations here have been chosen with much more care than in most other My Music Center variants, which within the narrow hardware limits makes the preset sounds here indeed sound like what their names suggest. All sounds employ a 2nd suboscillator for chorus, which is here detuned very little; like with Feng Yuan 28061 the chorus tremolo speed increases with higher notes. Because most presets sound like expected, I only explain the unusual ones here. Likely there are also some additional waveforms in comparison to the old My Music Center, since e.g. the "pipe" sound is a sonorous metal pipe organ rank timbre, which also exists on the greatly versatile Potex - Super Jam. "organ" decays a little after its slow attack and thus resembles a cello. "music box 1" has a 2s long sustain, while "2" is rather a slowly decaying bowed glass. "e. guitar" is more an e-piano, "jazz guitar" a banjo. "string 2" could be also a warm and sonorous reed organ. "tuba" turns harsh in high notes but sounds ok in the bass range. "synthetic brass" sounds a bit like a small plastic reed organ. "whistle" has strong chorus and sustain and reminds rather to a bowed glass or vox humana organ rank.

The 'effect' button adds one of 3 effects to the main voice sound; "Vib." adds a square 7Hz vibrato, "Echo" chops and retriggers the note with about 2.5Hz and falling volume, which produces a kind of 4 second long echo. Quite unique is that short notes are not affected; the echoing starts only when the note sounds long enough to make it re-trigger the first time, which can either be caused by long internal sustain of the selected sound or by holding the key long enough. "Rev." is no reverb, but genuinely only a stronger detuned (but still harmonious) version of the normal chorus.

The synthesizer is easy to use but not remotely as versatile as e.g. a Casio VL-Tone 1. To use it, turn the mode knob to 'voice' and press 'program'. Select with the dial one of 6 volume envelopes {piano, music box, guitar, violin, saxophone, banjo} and press 'enter'. Select with the dial the first waveform from the 30 preset sounds and press enter. Repeat the same for the 2nd waveform (both are mixed to create the timbre, use both the same when you want only one waveform). You can test the sound on the keyboard. Press 'program' again to save the sound. But instead of letting the user decide which sound he wants to overwrite, the instrument apparently stubbornly saves in ascending order to the sound numbers from 31 to 35 (named 'CUS1'..'CUS5') and overwrites the first one again when more than 5 user sounds are saved. (It's a good idea to write down the selected envelope and waveform numbers during sound programming.) Unfortunately there is is no MIDI- in jack to be used with the synth. A bizarre bug is that when a user sound is selected and the instrument is switched into MIDI mode, then the 2nd subvoice of played notes is muted semi- randomly at about every 2nd pressed key. The phenomenon does not occur with enabled vibrato or echo effect. The 6 volume envelopes are nothing remotely spectacular. "piano" and "guitar" are what their names suggests. "music box" is percussive and decays with 2 seconds long sustain (3 with held notes). "violin" is a continuous tone with non- percussive attack and short sustain; "saxophone" is the same with more percussive attack. "banjo" is almost identical with "guitar" and only decays a tiny little slower (which is mostly audible in the timbre of the zipper noise of high notes).

In MIDI mode neither rhythm nor any other fancy functions can be used. Bizarre is that the preset sound is now stepped up and down with the 'learn' and 'one key' buttons. Also the 'percu' button (drumkit mode) and the 'effect' button still work. (I haven't tested MIDI yet.)

The 10 accompaniments and the medium resolution percussion samples strongly resemble K-Mark WP9019A1. Many rhythms hammer like a wild staccato with an overdose of shaker noise. Unfortunately there are no separate volume controls for rhythm and accompaniment. The accompaniment patterns are over- orchestrated and thus less versatile; most remind to reggae, and with accompaniment the main voice turns monophonic. The accompaniment continues during rhythm fill-in. A nasty bug is that the transpose +/- buttons do not transpose also the accompaniments, which makes them almost useless. The same bug also exists in the WP9019A1, with the difference that there the buttons do nothing so long the accompaniment is running, and that I had added them only as an easteregg. The 'percu' button switches the white keys of the right keyboard section into drumkit mode. The cymbals even sounds nicely metallic, although the samples are thin and stop with a sudden end click. A little strange is that the sharps (black keys) between the white drumpad keys here still play their normal notes. The drumpad keys also show wrong icons: {snare, tom H, cymbal R1, cymbal S, base M, cowbell, hand clap, shaker, pause} instead of {base, snare, close hihat, cymbal, tom, cowbell, hand clap, shaker, pause}.

To program a rhythm turn the mode knob to 'rhythm' and press 'program'. Enter the (monophonic) rhythm step by step with the keyboard drumkit keys; use the rightmost key to enter pauses. The rhythm has to be at least 16 steps long. Press 'replay' to hear it and press 'program' again to save it. Like with the synthesizer sounds, the instrument stubbornly saves in ascending order to the rhythm numbers from 11 to 16 (named 'CUS1'..'CUS6') and overwrites the first one again when more than 6 user patterns are saved. User patterns can neither be combined with accompaniment nor use a fill-in.

The primitive record/ playback sequencer is fairly useless but at least it can keep its data in memory. To use it, turn the mode knob to 'song'. Press 'program', play a monophonic melody to be recorded and press 'replay' to hear it. Press 'program' again to save it to 'CUS1' (song number 11) into memory. To play the saved song later, select song 11 again and press 'enter'. Selecting other numbers plays the demo melodies.

The 10 demo melodies of this instruments are:

Silent Night
Joy to the World
Susanna
It is a Little World [named "It is a Little Word" on Sankai 01504H]
London Bridge
Yankee Doodle
Auld Lang Syne
The Rhythm of Rain
Sailing
Surprise Symphony

These 10 songs are also used for the play teaching mode, despite their complex polyphonic arrangements contain so many play faults (or were these considered jazzy improvisations???) that it is questionable how anybody should learn correct playing from them. Some of the demos strongly resemble those on Sankai 01504H, with the difference that the latter plays them with less flaws. Press 'learn' to start the teaching mode, which works similar like key lighting. The LCD indicates which key you should press while the accompaniment of the song repeats in a loop until the correct key is hit; even the correct finger is shown. Unfortunately it does not show at all the correct play timing but lights up the next key as soon the previous one was hit, and the notes to be played are always only monophonic. Another training mode is 'one key', which behaves similar except that any key presses here step through the melody. Both modes can also use the user song '11' in the sequencer, although the latter neither has rhythm nor accompaniment to learn the correct timing from. Like with My Song Maker, also here the special accompaniment loop of the one key play mode can be abused for tekkno. It's a pity that the programmer has not made them available as additional standard rhythms and accompaniments. You can also transpose the main voice in both modes, which will not transpose the special accompaniments and thus sound even more cacophonic than the normal arrangements.

Likely a predecessor of the KE-491 was the Superb Sound EK-905 (neither synth nor MIDI, based on FM sound). Another high fidelity My Music Center successor was the fullsize Yongmei YM-2100.

*removal of these screws voids warranty...*

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