Pan
Toys MC-7,
TrendLine MC 3700,
Fujiyama KS-37 |
squarewave keyboard with analogue rhythm
& monophonic accompaniment |
|
|
|
These keyboards belong to a very odd squarewave hardware class that
was likely a predecessor of the Hing Hon
EK-001 and possibly of MC-3. At
the one hand it features accompaniment, programmable analogue rhythm and
even a simple sequencer, but at the other hand the sound is plain squarewave
with the most crude and primitive volume envelopes you can imagine, the
whole thing is only 2 note polyphonic and the automatic accompaniment features
neither chords nor a separate bass line but simply occupies the 2nd melody
voice with a monophonic pattern.
But these instruments are nothing bad; they sound just in a sympathetical
way artificial and puristic and have much similarity with music from historical
videogames or simple Commodore C64 homecomputer compositions. Especially
the accompaniments sound nicely cheesy and innocent.
(Note: This thing sounds quite nice, but don't buy one of these
so far your only intention is to get a keyboard with faithfully imitated
natural instrument timbres. Remember, this is a squarewave instrument and
its sounds do not even remotely resemble what is written on its buttons,
thus bought with wrong expectation it may disappoint you.)
Pan Toys MC-7
While the front panel of this instrument is labelled "MC-7", on the
back of the case stands also the brand name "Pan Toys". This instrument
was also released as Elite MC-7, GPM MC-7 and Levis MC-7
(seen on eBay). Besides that it is much bigger (midsize keys), the
case design of this instrument resembles very much the Hing
Hon EK-001, and indeed also a mini keys version of it was released
as Elite MC 2000,
Transtec 893 and Grand Prix KB 893
(seen on eBay), which case looks besides the different button layout
exactly like my EK-001. A case variant of the MC 2000 with
centered drumpads shaped like
Casio SK-5
and SK-8 was released as
Fujitone
II and Monacor MC-2000A (see below).
main features:
-
37 midsize keys
-
built-in speaker (quite large, sounds bright and lacks bass)
-
main voice polyphony 2 notes (only 1 note with accompaniment)
-
5 step main volume slider (step 0=mute, all others are quite loud)
-
5 step "accomp vol." slider (mislabelled rhythm volume control, step 0=mute)
-
8 OBS preset sounds {clarinet, violin, oboe, piano, elec. guitar, xylophone,
harpsichord, mandolin}
-
8 OBS preset rhythms {disco, march, rock, waltz, pops, 16 beat, rhumba,
bossanova}
-
sustain & vibrato buttons
-
tempo +/ - buttons (16 steps)
-
combined tempo & power LED
-
primitive sequencer {record, play/ stop} (28 notes, only monophonic main
voice, no edit)
-
3 plastic drumpad buttons {low tom, high tom(?), hihat} (the icons instead
depict a base, snare and hihat)
-
programmable 16 step rhythm pattern ("custom drummer")
-
monophonic accompaniment (plays the current main voice, has neither manual
bass nor chords)
-
main voice is plain squarewave with different pulse widths and a simple
capacitor envelope. The envelopes are extremely crude; decay envelopes
have always a fixed speed, thus shorter ones are simply cut with an audible
click. Continuous (organ- like) tones have no envelope at all.
-
simple analogue percussion {low tom, high tom (or base??), hihat}. Both
drums are dull, the hihat is made from transistor noise.
-
CPU "SC-MC-2, 233515" (42 pin DIL). Due to the
Letron's main CPU
has a "MC-3" in its name, this was likely a predecessor and was possibly
also made by Medeli.
-
demo melody (a slow polka that resembles "Little Brown Jug", uses the "pops"
accompaniment)
-
battery alarm (plays 2 notes when not played for a minute - also when mains
operated)
-
power supply jack
(old eBay picture of my specimen.) |
|
|
eastereggs:
-
CPU pin 8 outputs fast trigger pulses for an additional percussion instrument
(like drumrolls, also during the custom drummer pattern).
-
3 additional very low bass note(?) keys addable (unlike normal low note
keys, these don't affect accompaniment)
This is one of the keyboards I believe to have seen as the smallest "Fujitone"
in shopping centers of my childhood; particularly I remember well how I
mused about its lousy "xylophone" sound and the colourless drums at a time
where the first Casio ToneBank keyboards (SA-20 etc.) appeared
with lots of (at that time) very realistic sounding timbres.
The PCB of this instrument is rather small, and like the bizarre HBATEC
it contains only a single digital IC (CPU) and lots of analogue stuff (mainly
percussion). There are also many unused drill holes without traces on it;
possibly a 4th percussion instrument was planned here because the CPU outputs
a sort of drumroll pattern at an unconnected pin. Very unusual is that
the keyboard matrix inputs of this CPU respond only on very low ohmed voltages
(about 330 Ohm). |
|
The sounds of the MC-7 are extremely odd, because the timbres are just
plain squarewave with different pulse widths and so archaic, crude volume
envelopes that even a Letron or Casio
VL-1 sounds almost natural against it. When sustain is switched
off, after releasing the key any sounds stop immediately with an audible
click, and the sound presets itself also contain neither vibrato nor tremolo.
The squarewave timbres are quite bright and have a somehow grainy purring
texture; it is not zipper noise but rather an intermodulation with internal
digital signals; it may be that the mandolin ring LFO is always running
and somehow crosstalks into other preset sound those don't use it. When
2 notes are held, the timbre flutters with a strange irregular textures,
which sounds quite interesting. Similar like the simple MC-11,
this instrument permits (with some skill) to play extremely short, blipping
notes those most modern keyboards would rather ignore or play too long.
The "clarinet", "violin", "oboe" and even the "elec. guitar" are nothing
but plain squarewave tones of different pulse widths without any envelope
(i.e. a simple toot or beep like from a cash register or similar). The
"piano" and "harpsichord" have a decay envelope, but with sustain enabled
they ignore the key press duration. The "xylophone" is nothing else but
a short beep (0.2s?) with sudden end click, which stops without sustain
even earlier by releasing the key, but also with sustain it won't get any
longer than its maximum length (which is much shorter than e.g. the "piano"
or any of the continuous tone sustains). The "mandolin" of this little
tablehooter even rings (about 8Hz), but like the latter it can also not
be really prolonged by sustain. The sustain duration with other preset
sounds corresponds to the held "piano" envelope.
Unlike the Letron and various similar squarewave keyboards, when
OBS sound preset buttons are pressed with held down keys, this instrument
does not immediately switch the timbre of the still sounding notes, but
assigns the new selected sound either only to the next played notes or
makes the held notes fade silent and then retriggers them with the new
timbre. What exactly happens depends on the previous and new selected sound
preset; e.g. a held "mandolin" note stops ringing as soon a different sound
is selected. This can be used as a sound effect, although the behaviour
can be difficult to predict.
Like the arpeggio of other instruments, the accompaniment can play in
different keys despite it is monophonic; for this simply 1 or more keys
in the left keyboard section have to be pressed, similar like a single
finger chord (1 key= minor, 2 keys= major, 3 keys= 7th or the like). Although
the accompaniment plays always with the currently selected main voice sound
(including the vibrato setting), it uses no sustain. Rhythms can be switched
immediately and always (re-)start from their 1st step as soon any OBS rhythm
button is pressed. With some skill this can be uses as a realtime variation
feature. The rhythm only employs 2 dull analogue drums (like muffled congas
with short decay envelope) and a hihat. With my first MC-7 the hihat
sounded quiet like hit with too little force. Later I bought another Pan
Toys MC-7 (to gut out for repairing my rare Fujiyama
KS-37), which hihat sounded noticeably louder with more percussive
attack (like a brushed snare); possibly one had a broken electrolytic cap
or different discrete components.
The monophonic sequencer is useless because it holds only 28 notes and
works not together with rhythm. The "custom drummer" otherwise can be combined
with the preset rhythm accompaniments, and even length of the drum pattern
depends on the selected preset rhythm, thus it is a quite interesting feature
that may be good for tekkno. (The analogue drums can be likely circuit-
bent similar like I did with my HBATEC.)
The MC-7 has no sound output, even the lowest volume setting
is quite loud and it generally sounds quite bright and a little harsh (analogue
distortion?), but the timbre is still pleasant. (I didn't modify this tablehooter
because I also own the TrendLine MC 3700.)
TrendLine MC 3700
This instrument is based on the same CPU like the MC-7, but has
a different PCB. It sounds less harsh (e.g. the clarinet sounds more credible;
likely it was built with different capacitor values). Also the drums sound
different; they are more melodic here and particularly the high tom resembles
more a muffled plastic pot and does not resemble at all a base drum like
the MC-7 one. Very unusual is that this instrument has no master volume
control, but only 2 separate "faders" for main voice and rhythm volumes,
those behave totally independent (i.e. reducing the "main volume" does
not also reduce the rhythm volume).
(This is an eBay picture, showing
my specimen.)
|
different main features:
-
2 built-in speakers (stereo - rhythm is to the left, main voice in the
middle)
-
real "main volume" & "accomp volume" potentiometers
-
3 very responsive, triangular plastic drumpads
-
CPU "SC-MC-2, 053025" (42 pins)
-
microphone and headphones jack
This instrument was also sold as Bestar MC 3700, Mundia MC-3700
MP180 and Kamosonic F1. The case design of this instruments
has many style elements common with the MC-3
keyboard Tristar MC 3000 and the GPM
MC-5000.
Fujiyama KS-37
This was my first specimen that I found of the MC-2 hardware class (see
Pan
Toys MC-7). It was sold to me on flea market and seems to be very
rare, but unfortunately it was completely brain- dead; apparently someone
before me confused the AC- adapter polarity and though toasted it. The
only still working parts were the amp and the transistorized analogue drum
circuit. Later I repaired it with parts from a Pan Toys MC-7.
The case is brown and the speakers are left and right next to the keyboard
instead of above it ( =>wastes space). It has 3 orange drum pad buttons
and most other controls are similarly labelled like the Letron,
but the keys are slightly longer than normal midsize keys.
different main features:
-
2 built-in speakers (mono, sound bright and a bit thin)
-
8 OBS sounds {mandolin, violin, harpsichord, e-horn, piano, xylophone,
oboe, clarinet} (The strange sound name "e-horn" corresponds to "elec.
guitar" on MC-7.)
-
3 drum pad buttons (orange oval plastic, shape similar like with the Hing
Hon EK-001)
-
genuine analogue master & rhythm volume sliders
-
analogue drum circuit {conga, bongo, close hihat}. The bongo/ conga are
rather dull and sound like muffled plop noises.
-
CPU "SC-MC-2, 933021" (42 pin DIL)
The
slightly slanted side speakers are a well recognizable style element of
this case; I believe to remember that old Fujitone keyboards featured
them also. |
The
drumpads have wrong icons {base, snare, open hihat}; genuinely they play
[conga, bongo, close hihat}. |
eastereggs:
-
reduced supply voltage mutes the hihat.
modifications:
-
polarity protection diode added.
-
later faulty CPU and zener diode replaced with one from Pan
Toys MC-7.
-
GND lines rewired and shielded audio cable added to reduce main hum.
-
confused speaker polarity corrected.
notes:
I later repaired the Fujiyama KS-37 with parts from a 2nd Pan
Toys MC-7 that I bought for this on eBay. I soldered in
a socket for the new CPU (40 pin socket + piece from another socket to
get 42 pins), and at low voltage it indeed seemed to work, although there
was plenty of mains hum from my unregulated AC- adapter. But when I increased
the voltage (jack was labelled 9V), the CPU crashed and didn't start anymore
for many minutes. I first thought I had toasted it - arrrg! - But after
waiting about 30 minutes, at low voltage the instrument worked again. I
examined the PCB and found out that the zener diode that together with
a transistor was intended to regulate the CPU voltage was defective (open,
took no effect) and thus the CPU got almost the full supply voltage instead
of only 5V. Either the original CPU died by that faulty zener diode, or
the confused polarity by the previous owner not only toasted the CPU but
also the zener diode. I replaced it with the zener from that MC-7 to protect
the CPU properly. It worked well now but there was still much mains hum
because the GND line was wired very badly; the entire ground current of
the supply voltage was drawn through the audio GND line at the volume potentiometers
and thus caused a voltage drop. I separated both grounds and wired the
audio and audio GND lines separately with a shielded cable to the amp section
=>hum is gone. Initially also the left speaker had wrong polarity, but
wiring it correctly didn't boost the bass response really much.
I first hoped this rare instrument had different analogue percussion
(and made use of the mysterious 4th drum output of the CPU), but it doesn't
differ that much from MC-7.
The 2 drums are quite dull with short envelope; the higher one (bongo or
high tom) sounds like a muffled plop noise that reminds to opening a plastic
bottle. At higher volume setting the drums distort and thus get more percussive.
Despite like with other MC-2 variants the power LED is mislabelled "tempo"
and has a separate lead to the main PCB, here it doesn't flash but the
unlabelled LED above the "accomp" button flashes instead. Bizarre is also
that on the button names are printed on the back of the control panel PCB,
but many of them differ from the actual control panel writing and they
have plenty of Engrish misspellings. |
The Fujiyama KS-37 looks quite much like what I remember from
my childhood as a "Fujitone". I would love to find one of these
first Fujitones (not a Fujitone IIIb but a really old one). A variant
of the Fujiyama KS-37 with similar case but more rectangular speakers
and drumpads was apparently released in China with the brand name
Tongmei
(not Yongmei, seen on eBay).
These are some pictures and model
names I found on eBay:
Transtec 893
same case:
Elite MC 2000
Gran Prix KB 893
Rhapsody
This was the direct predecessor of the Hing
Hon EK-001. |
Fujitone 2 (Fujitone II)
same case:
Kazama EK-828 CP
Monacor MC-2000A |
Tongmei |
Instruments of this hardware class can be recognized by the combined power
& tempo LED (i.e. the power LED is labelled "tempo"), the presence
of 8 OBS rhythms and 8 OBS sounds, 3 drumpads with 2 custom drummer buttons
and the sequencer "record" and "play/ stop" buttons. Regarding the CPU
type label, also a variant called "MC-2" may exist, which appears to be
the genuine name of this hardware class (e.g. MC-3 keyboards (like
Letron
MC-3) also have "MC-3" in their CPU name). A possible direct predecessor
of the MC-2 hardware class was the Superb
Sound EK-922. A possible successor was the Elite
MC2200. Another keyboard with similarly cheesy monophonic accompaniment
and analogue rhythm is the nice Casio
MT-40.
removal
of these screws voids warranty... |
|
|
|
|
|
|
back
|
|