This ancient Bontempi keyboard has a lightweight grey plastic case with detachable keyboard lid and pull-out handle. I don't know how old it is, but the analog hardware looks like very early 1980th; it has only a monophonic envelope (i.e. when in piano mode a key is pressed, any held-down keys play at full volume again) and sounds very home- organ-like. The analogue drums with an astonishingly versatile accompaniment with arpeggio.

main features:

49 full size keys (with counter- springs and metal spring contacts - like 1970th home organs)
4 note polyphonic sound with monophonic envelope
6 preset sounds {organ, horn, oboe, strings, piano, harpsichord}
8 preset rhythms {waltz, tango, march, swing, slow rock, disco rock, bossanova, samba}
sustain switch
"memory" switch (chords are held after releasing their keys when on)
switch {full keys, free bass & chord, single finger chord}
switch {s. finger orchestra}
sliders for master-, rhythm- and arpeggio volume, rhythm tempo, balance (arpeggio vs. rhythm)
complex analogue hardware with multiple PCBs and many socketed ICs
analogue(?) sound generator with 4 main voices (monophonic envelope), 4 (?) chord voices + bass (own envelope) and arpeggio (own envelope?). Drums are analogue and sound very distorted, hihat and snare are made from transistor noise.
complex multi- chip hardware:
CPU= "~ S/B 8335, COP420-KPN/N, 27430700" (28 pin DIL)
sound IC= "AMI 8340WN, 27430520, KOREA" (24 pin DIL)
detachable special AC adapter cartridge
tuning trimmer at the bottom
headphone and AC adapter jack
What I particularly like with this keyboard is the very versatile accompaniment; e.g. the arpeggio changes depending on how many chord keys are pressed and whether it is in fingered or single finger chord mode. The accompaniment accepts also any non- chord key combinations and can e.g. play a sequence of the same note from different octaves etc. When "chord memory" is off, the accompaniment falls silent by releasing the chord keys (in synchro mode rhythm stops too?), which makes it possible to play with rhythms in interesting ways. What I like less is the monophonic envelope in piano/ harpsichord mode and that of the only 6 sounds 2 (organ and horn?) sound almost identical.

I yet couldn't find out how the main and chord sounds are generated. The waveforms seem to leave the soundchip somewhat encoded or multiplexed, because by connecting an amplifier I hear only digital pulses and the arpeggio and bass squarewave tones, but not the main and chord voices. Possibly they are decoded by some 74LS in between or even generated outside by something analogue; e.g. the oboe timbre is very different from squarewave, but it also may be just a filter. On the 28 pin main CPU(?) that is connected with the keyboard stands "~ S/B 8335, COP420-KPN/N, 27430700", on a 24 pin soundchip that outputs at least arpeggio, bass, envelope signals and rhythm trigger pulses stands "AMI 8340WN, 27430520, KOREA".

At the case bottom there is a sticker "HB 412.15" and the following embossed text:

Design Guigiaro

Made in Italy - Fabriqué in Italie
by-par BONTEMPI
Potenza Picena (MC)

свернуть