owner: William Blakeney

Designed for classroom instructional use, a cheap alternative to the 2600, this system consists of individual battery-powered modules similar to those found in the second generation of ARP Odysseys. The basic setup included the keyboard and the VCO (modules 1504), VCF (module 1506), envelope (module 1506) and a battery operated amplifier/speaker modules. Also available were modules for LFO, VCA (module 1509), noise(module 1503), sample-and-hold (module 1507), ring modulator, multiple (module 1510), and mixer/atenuator. The modules are connected by mini cables (grey, yellow, or red), and were designed to be used with or without a keyboard. ARP sold each module for between $40 (for the multiple module 1510) to around $70. The keyboard sold for around $175. They drafted workbooks, one for each module, with a comprehensive teacher's manual.

MSL Modules

module 1501 ADSR envelope generator	module 1503 Noise Generator	module 1504 VCO (Voltage Controlled Oscillator)
module 1506 VCF (Voltage Controlled Filter)	model 1507 Sample-and-Hold	model 1509 VCA (Voltage Controlled Amplifier)
module 1510 Multiple Box	All images courtesy of William Blakeney

There was possibly a Mark II version of the MSL (at least in prototype form). These units had anbled front panels for easier access to controls.

In 1980, when ARP started to go under, they sold the MSL to Electronic Music Products and Services, of Merrick, NY, who designed a 3-octave keyboard and a case which stored the modules vertically with the keyboard.

[from The A-Z of Analogue Synthesizers, by Peter Forrest, published by Susurreal Publishing, Devon, England, copyright 1994 Peter Forrest]