Polyphonic Synthesizer:

Kawai SX-210
Modulus 002
Waldorf Blofeld
Waldorf rackAttack
Waldorf Wave
Waldorf XTk30
Wersi Stage Performer

Monophonic Synthesizer:

Casio VL-1 Tone
Dübreq Stylophone
Korg M500 MicroPreset
Modulus monoWave
Moog miniMoog
Moog Minitaur
Moog Prodigy
Moog Sub Phatty
Moog Taurus III
Moog Voyager
Synthesizers.com Modular
VacoLoco Zira
Waldorf Pulse
Waldorf Pulse 2

String Machines:

Crumar Performer
ELKA Rhapsody 610
Eminent 310 theatre
Hohner String Performer
Hohner String Vox
Logan String Melody
Waldorf Streichfett

Other Keyboards:

Manikin Memotron


Behringer Mixer MX2642A
Behringer Mixer MX8000
Behringer Rack Mixer RX1602
Boss DR-220E
Digital Raagini
EEH DS 500
Electro-Harmonix Small Stone
Georg Mahr Midi-Ratsche
Ibanez Digital Delay DM1000
Lexicon Model 200 reverb
Mode Machines Krautrock Phaser
Moogerfooger Ring Modulator 102
Moogerfooger 12-Stage Phaser 103
Moogerfooger Analog Delay 104Z
Moog MP201
Schrittmacher's Inside
Schulte Compact Phaser
Simmons SDS-V (w/o drum pads)
Synthoma Élkorus
VacoLoco Tron
Waldorf 4Pole
Waldorf EQ27
Wersi Voice (BBD FX)
Waldorf midiBay
Waldorf Becher/Mugs


Access MicroWave controller
Alesis Andromeda A6
ARP Quartet
EES Midi CV7
Crumar Multiman S
ELKA Solist 505
ELKA x705
Emu Emax II
Farfisa Soundmaker
Farfisa Syntorchestra
Hohner ADAM
Jen SX1000
Keio Mini Pops 3
Korg PE1000 (Poly Ensemble)
Korg PE2000 (Poly Ensemble S)
Moog Satellite
Oberheim Matrix 6
PPG waves
PPG wave 2.3 (V8.3)
Rhythm Ace 2l
Roland TR 606
Roland M-VS1
SCI model 700
Seiko DS 202+310
Sound-Art Chameleon
Technosaurus Cyclodon
Vermona Piano-Strings
Waldorf microQ keyboard
Waldorf Q
Waldorf XT30
Waldorf Gekko Chords
Waldorf Gekko Arp
Waldorf microWave
Waldorf waveSlave
Wersi Baß Synth
Wersi String Orchestra


EM Portal Forum


K. Schulze's "Sense"


© Till Kopper

Logan String Melody

Logan String Melody

Logan String Melody

Build from 1973 to 1976 it was one of the better string sound keyboards. It sounded better then the other italian string keyboards of that time. This was due to the fact, that each of the 49 keys got its own simple AD-envelope. This was way better then a simple on/off one of more organ like sounding string machines or one paraphonic envelope for all keys together.

The keyboard is always split int two nearly equal sized ranges. In each of these ranges you can mix a combination of three string sounds. Each string sound was a copy of the other but one octave higher in pitch.
And you can control the attack and the decay times per keyboard zone. Ranging from zero attack or decay to a smooth long one. Well scalled mins and maxes.

And on the black metal above the volume sliders you find the trim pot hole for adjusting the rather stable master pitch of this instrument. The push buttom right of this is labeled "Orchestra". This raclls a preset selection of all the available parameters. But don't be fooled, this will not imitate a real orchestra at all. It will just set the strings to a nice mix and envelope.

Of cause there is a ensemble effect added which sound very much like other ensemble effects based on tripple bucket brigade transistor arrays with two controlling LFOs. Like the one used in the ELKA Rhapsody, the Crumer Perfourmer or in the Wersi Voice effect. They technically very related and using sharing more or less the same parts. But with little changes here and there.

The Logan String Melody II (1977 - 1980) got addition parameters and added presets like ORGAN.
The Wersi version of this one also added parameters for changing more sound parameters. Including HAWAII (the typical Wersi 1 octave glide down and back upward again), simple tone controls and a pitchbend slider named SLALOM. Well, except for the tone control these are not the most usefull additions possible.

The left hand range also give you the option for adding a monophonic bass sound with extra volume and percusion attack control (the two yellow sliders to the very left).

Logan String Melody inside

You open the Logan as easy as other italian string machines from this time: undo 2 screws on the top to open the top lid.

We see the monophonic bass board left and the master oscillator with the top octave divider chip on the small board in the middle. And the power supply on the very right

The descrete build master oscillator is tuned to 1059 kHz and feed into a MK50240/1 top octave divider chip (a M50241 like chip). This chips divides the ingoing top oscillator's square wave into 12 different squarewaves that are each tuned to one of the 12 notes of an equal tempered octave. These 12 signals are called the top octave, because they represent the highest available tuned to keyboard notes this instrument is able to play. Ranging from 4184,7708 Hz (a "B") to 2215,4812 Hz (a "C").

And undo screw on the bottom to be able to flap the keyboard action upwards to see what's below.

Logan String Melody inside

Under the top lid we see from left to right:

  • The left board that does the needed bass and treble attack and sustain control voltages for each voice, controls the bass percussion envelope and does the preamplifying of the out signal
  • this big board it the tripple transistor bucket brigade chorus using the then most widely used TCA350 chip as most italian string machines did
  • On the right we have the two LFOs of the tripple chorus. One LFO is set to slow (about 0.6 Hz) while the other is set faster (6.0 Hz).
    Then each LFO is phase shifted by zero, 120 (1/3 of the cycle duty) and 240 (2/3 of the cycle duty). Each of the three differend phases is then mixed together with the same amount of phase shifted LFO at a ratio of 79% of the slow LFO and 21% of faster LFO.
    This gives a complex modulation of the choruses in order to get an ensemble effect.

Logan String Melody inside

Under keyboard is the big board with the electronics needed for each individual key. Each key uses a SAJ210 divider chip to divide the frequency of the top octave oscillator down to the desired key and to the three different octaves (4', 8' and 16') needed for this key.