ASM-1

Analog Synthesizer Module

Other names for this product: ASM1, ASM 1,

Courtesy/Thanks to: Gene Stopp

Description: Please Observe! The ASM-1 PCB is discontinued and is replaced by the ASM-2 PCB.

The ASM-1 is a DIY analog synthesiser created by Gene Stopp and was derived from
a number of Electronotes projects submitted by Terry Mikulic and Bernie Hitchins.
The ASM-1 design brings together the basic modules for a classically
configured synthesiser on a single pcb.
Although on a single pcb, each module is fully self-contained with only the power rails common to all modules. This allows the user the freedom to use the ASM-1* in any type of design desired, from a small pre-patched unit to a fully modular system.
(words by Laurie Biddulph who runs a DIY site in Australia and also sells premade PCB's for the ASM-1 and ASM-2 Synthesizers).

The ASM-1 Analog Synthesizer Module was created for a few reasons:

1. I wanted to build a manually-patched polyphonic analog music synthesizer for
   
   my own use, having given up hope of finding an old Oberheim 8-voice for a couple
   
   of hundred bucks. Making a circuit board for each voice is only marginally
   
   crazzy - making the whole thing on vectorboards would be totally crazy. I'm only
   
   marginally crazy.
   
   
2. If i did make a circuit board, I could make extra ones and sell them to
   
   synthesizer builders, to help pay for the rather expensive PCB setup costs at
   
   the local shops.
   
   
3. I like to design circuit boards.

The ASM-1 contains a fairly

standard arrangment of traditional analog synthesizer modules, in what can be

considered a compromise between simplivity and usefulness. The circuit sections

are:

2 Voltage Controlled Oscillators (VCO's)

Sawtooth and variable rectangular outputs

1 Voltage Controlled State Variable Filter (VCF)

Lowpass, bandpass, highpass and notch outputs

2 Voltage Controlled Amplifiers (VCA's)

Linear response

2 ADSR Envelope Generators

Exponential curves

1 Low Frequency Oscillator (LFO)

Triangle and square outputs

1 Noise Source

White, pink and random outputs

1 CV Glide Buffer

Linear or exponential glide

These circuit sections can be considered "modules" in the

modular synthesizer sence, since they are not interconnected in any way on the

circuit board other than by power and ground busses. Therefore the builder has

the freedom to use the ASM-1 in any type of design desired, from a small

pre-patched expander module to a fully patchable semi-modular system.