Buchla 200 series Electric Music Box

The Buchla 200 series Electric Music Box is an electronic musical instrument manufactured by Buchla & Associates in Berkely, CA from 1970-1982. It is a modular analog system comprised of a collection of individual modules. Systems are assembled in cabinets designed to accept modules occupying between 1 and 6 modules spaces in width, each space being 7" tall and 4.25" wide.

Power for the modules is provided by a power supply contained within the cabinet. Voltage rails of +15, -15 and +5 volts are included on all supplies in the series. Some of the power supplies also provide +24, -24, and +12 volts. Noisy and Quiet ground lines, generally those for digital and analog circuits respectively, are provided on all supplies as well. Generally, only older modules in the series require the 24 volt lines and only later ones require the unregulated +12 volt line (using it only to power LEDs). The connectors used to route the power changed over the production years, but finally settled on a 10 pin edgecard connector with pin 7 blocked to provide a directional key.

What separates the 200 series from its predecessor, the 100 series, is that almost every parameter is under voltage control. Functional density is higher, packing several functions into each module. The electronics employ the use of op-amps, CMOS & TTL logic chips and quite often Vactrols, a device with an LED and a photoresistor in a light-tight shell. The approximately 10ms rounded attack and 50ms release [Vactec VTL5C3 data sheet] of the Vactrols contributes substantially to the "natural" sound that Buchla 200s are credited with. The 200 series also often shows the state of its outputs with LED indicators.

The modules that were manufactured for the Buchla 200 series are as follows:

204 Quad Spacial Director
205 Matrix Mixer
206 Dual Mixer
207 Mixer/Preamplifier
208 Stored Program Source (Part of the Music Easel)
212 Dodecamodule
214 Music Easel Power Supply
215 Power Supply
216 Touch Controlled Voltage Source
217 Multiple Touch-Controlled Voltage Source
218 Touch Activated Voltage Source
219 Polyphonic Touch Activated Voltage Source
221 Kinesthetic Input Port
226 System Interface
227 System Interface
230 Triple Envelope Detector
232 Frequency Detector
237 37 Key Organ Type Keyboard
238 61 Key Organ Type Keyboard
242 Programmable Pulser
245 5 stage Sequential Voltage Source
246 16 stage Sequential Voltage Source
248 Multiple Arbitrary Function Generator
256 Dual Voltage Adder
257 Dual Voltage Processor
258 Dual Voltage Controlled Oscillator
259 Programmable Complex Waveform Generator
264 Quad Sample & Hold/Polyphonic Adaptor
265 Source of Uncertainty
266 Source of Uncertainty
270 Quad Preamplifier
275 Dual Reverb/Equalizer
277 Signal Delay Unit
280 Quad Envelope Generator
281 Quad Function Generator
284 Quad Voltage-Controlled Envelope Generator
285 Frequency Shifter/Balanced Modulator
288 Time Domain Processor
291 Dual Voltage-Controlled Filter
292 Quad Lopass Gate
294 Four Channel Filter
295 Ten Channel Filter
296 Spectral Processor
[Buchla promotional brochures]

In 2001, Buchla returned to the 200 series and released the Barber Pole modules, models 260 and 297. The 260 is a Duophonic Pitch Class Generator, an oscillator capable of creating out a sound that seems the same in every octave. The 297 is an Infinite Phase Shifter. More often referred to as a barber pole phaser this module creates a filter effect that seems to rise or fall, but never actually changes frequency range being effected.

In 2003, Buchla released the 255 Control Voltage Processor. Although released shortly before the 200e system, it is not considered part of the 200e system, likely because of its lack of patch storage capability, and received a non-"e" model number. This was the first Buchla module to be released with the 200e's characteristic Selco knobs, which are white capped to indicate that the values will not be stored by a 225e module.