The Logan String Melody designed by Ing. Giuliano Costantini for Logan was a portable keyboard produced in two versions from 1973 to 1982. [1] Manufactured in Italy, it was sold under both the Logan brand name and re-badged as both a Hohner and Vox product. The Vox version was called The String Thing but still featured the Logan brand name on the back of the case.
The keyboard consists of four octaves split into two nearly equal sized ranges. In each of these ranges a combination of three string sounds can be mixed using faders labelled Cello, Viola and Violin. Each string sound is pitched one octave apart. In addition to the separate sets of faders for the string sounds, each range has a sustain and release fader. The lower range also features a simple monophonic synthesiser that is controlled from using faders labelled Bass and Perc.
On the first version, there is a button labelled Orchestra that has hard wired settings and disables the faders for the string sounds. The second version, the String Melody II introduced in 1977, added more buttons for further hard wired settings. [2]
It came in a heavy wooden case and weighed 23 kilograms. It has full polyphony with a variable-gain amplifier for each key and a BBD (bucket-brigade device) ensemble effect that gives it the distinctive string synthesizer sound. Sound production begins at a high frequency square wave generator, then flows to the frequency divider, a Mostek MK50240N integrated circuit for the highest octave. These top octave frequency dividers were commonly used in electronic organs of the period. The lower octaves are divided by nine 7-stage SAJ210 dividers. The square wave passes the variable-gain amplifier built as a CV/Gate and a pulse conversion. Then the sound travels to the mixer, the ensemble effect, a presence filter and the output stage.
The monophonic bass sound available on the lower half of the keyboard has no variable-gain amplifier but has a low-pass filter.
The percussion bass is low filtered and has an attack of 30ms and a decay of 700ms, with no release. A simple gate variable-gain amplifier is used with a 47 μF capacitor, and the filter is behind it.
The ensemble effect consists of two modules – a dual low-frequency oscillator and the triple delay-line oscillator. The low-frequency oscillator puts out 0.6 Hz and 6 Hz mixed together as a tri-phase of the low-frequency oscillation to the delay-line oscillator. The delay-line oscillator consists of three TCA350 circuits – a chain of 185 MOS double transistor stages, which samples the audio signal, which is then modulated (FM) by the dual LFO so the output samples are shorter or longer. [3]
I noticed in the version different technologies for the dividers: Before the mostek divider, there was a dozen master oscillator bank for each chromatic tone. And early versions have transistor octave dividers instead of the SAJ210. The BBD was available in 3 cases: Type X (DIL14) in early String Melody I, type Y (DIL8) as standard in all string melodies and type Z (metal can).
The device shown in the picture is the one from trouby; it has an switchable input-jack beside the presets to use the ensemble effect for external signals. This photo (original or edited) must not be used as picture for selling activities.
An effects unit, effects processor, or effects pedal is an electronic device that alters the sound of a musical instrument or other audio source through audio signal processing.
An analog synthesizer is a synthesizer that uses analog circuits and analog signals to generate sound electronically.
A voltage-controlled filter (VCF) is an electronic filter whose operating characteristics can be set by an input control voltage. Voltage-controlled filters are widely used in synthesizers.
Linear electronic oscillator circuits, which generate a sinusoidal output signal, are composed of an amplifier and a frequency selective element, a filter. A linear oscillator circuit which uses an RC network, a combination of resistors and capacitors, for its frequency selective part is called an RC oscillator.
The ARP Pro Soloist was one of the first commercially successful preset synthesizers. Introduced by ARP Instruments, Inc. in 1972, it replaced the similar ARP Soloist (1970–1971) in the company's lineup of portable performance instruments.
Rocky Mount Instruments (RMI) was a subsidiary of the Allen Organ Company, based in Rocky Mount, North Carolina, active from 1966 to 1982. The company was formed to produce portable musical instruments, and manufactured several electronic pianos, harpsichords, and organs that used oscillators to create sound, instead of mechanical components like an electric piano.
The Korg Prophecy is a monophonic synthesizer released by Korg in 1995. one of the earliest commercial DSP physical/acoustic and analog "virtual" modeling sound synthesizers and Korg's first monophonic synthesizer since the Mono/Poly. The Prophecy employs Korg's Multi Oscillator Synthesis System (MOSS), which features digital oscillators capable of emulating synthesis techniques such as analog synthesis, FM and physical modelling. Emphasized for its portability, expressiveness, and engaging playability, a distinctive feature of the Prophecy is its multifunctional Wheel 3, nicknamed the 'log'.
The Access Virus is a virtual analog synthesizer made by the German company Access Music GmbH. It was first produced in 1997 and has since been upgraded frequently, with the company releasing new models about every two years. Early models include the Virus A, Virus B, and Virus C series, each available in various hardware configurations. In November 2005, the Virus TI series was released, including the 61-key Virus TI Keyboard and the 37-key Virus TI Polar. A small desktop model was released in February 2008 called the Virus TI Snow. A revision of the TI series called TI2 came out in March 2009, featuring faster digital signal processing (DSP) controllers, additional polyphony, more effects in the effect section and a slightly changed design. The Virus series also has come out with two software plugin versions: TDM for Pro Tools and VST for TC Electronic Powercore series. The term Access Virus can be used to refer to any one of these synthesizers. In 2024 Access Music discontinued the TI2.
The Memorymoog is a polyphonic electronic music synthesizer manufactured by Moog Music from 1982 to 1985, the last polyphonic synthesizer to be released by Moog Music before the company declared bankruptcy in 1987. While comparable to other polyphonic synthesizers of the time period, such as the Sequential Circuits Prophet-5 and Oberheim OB-Xa, the Memorymoog distinguished itself with an additional, 3rd audio oscillator per voice and greater preset storage capacity.
The Moog model 2090 Micromoog is a monophonic analog synthesizer produced by Moog Music from 1975 to 1979.
The Moog Sonic Six is a duophonic analog synthesizer that was manufactured by Moog Music from 1972 to 1979. Because of its portable design and built-in speaker, the Sonic Six was widely used for lectures and educational purposes, often by Bob Moog himself.
Polyphony is a property of musical instruments that means that they can play multiple independent melody lines simultaneously. Instruments featuring polyphony are said to be polyphonic. Instruments that are not capable of polyphony are monophonic or paraphonic.
The ARP Omni was a polyphonic analog synthesizer manufactured by ARP Instruments, Inc.
The Moog Prodigy was a monophonic analogue synthesizer produced by Moog Music from 1979 to 1984. Of the 11,000 produced, versions released after 1981 included a control voltage/gate input on the back that allowed the VCF to be triggered and controlled by an external source. These later versions began at serial number 4610. The official model number of the instrument is 336. 336A would indicate a domestic (US) model, while a 336BX would indicate an export unit.
The Freeman String Symphonizer was a 5-octave synthesizer of the 1970s. It was finally manufactured by the Chicago Musical Instrument Co. and was also known as the Cordovox CSS. Its sound was related to that of the ARP String Ensemble – cool, glassy-sounding strings. Eventually, its inventor Ken Freeman tried to strike a deal with the company Ling but they abandoned their interest in it. Lowrey a division of CMI finally struck a deal after some deliberation.
The Korg PS-3300 is a polyphonic analog synthesizer released by Korg in 1977. It was released alongside the PS-3100, a more compact variant featuring a complete synthesizer voice board for each of its 48 keyboard notes. The PS-3300 essentially combines three PS-3100 units, triggering all voices simultaneously with each key press and mirroring the PS-3100's overall design, featuring a total of 144 synth voices. The PS-3300 uses the PS-3010, a detachable keyboard equipped with an assignable joystick called the X-Y Manipulator.
The AX80 is a polyphonic analogue keyboard synthesizer manufactured by Akai Professional in 1984. It was Akai's first venture into the professional electronic musical instrument market. The AX80 used digitally controlled oscillators (DCO) and filter circuitry based on the Curtis Electronics CEM 3372 integrated circuit. It was marketed as part of a line of project studio equipment called the Akai Music Studio System, which included the S612 digital sampler the MR16 drum machine, the MS08 sequencer, and the MG1212 multitrack tape recorder, at a price of $1,695 US.
The AX60 is a polyphonic analogue keyboard synthesizer manufactured by Akai Professional in the mid-1980s. It was Akai's answer to the popular Roland Juno series synthesizers. The AX60 uses voltage-controlled analogue oscillators and filter circuitry based on the Curtis Electronics CEM 3394 integrated circuit.
The history of home keyboards lies in mechanical musical instrument keyboards, electrified keyboards and 1960s and 1970s synthesizer technologies.
The miniKORG 700 is a monophonic analog synthesizer released by Korg in 1973, marking their entry into mass-produced synthesizers and their first monophonic synthesizer. It was initially designed to be placed on top of an organ, so its controls are located below the keyboard facing towards the performer. An updated model, the miniKORG 700S, was launched in 1974, introducing a second oscillator that could be detuned, along with additional sustain and vibrato controls.