Buchla 200 series Electric Music Box
Encyclopedia
The Buchla 200 series Electric Music Box is an electronic musical instrument manufactured by Buchla & Associates in Berkeley, California
Berkeley, California
Berkeley is a city on the east shore of the San Francisco Bay in Northern California, United States. Its neighbors to the south are the cities of Oakland and Emeryville. To the north is the city of Albany and the unincorporated community of Kensington...

 from 1970-1982. It is a modular analog system consisting 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 inches tall and 4.25 inches 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
Edge connector
An edge connector is the portion of a printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector , and they also tend to be...

 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 op-amps
Operational amplifier
An operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output...

, CMOS
CMOS
Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

 & TTL
TTL
TTL may refer to:* Taiwan Tobacco and Liquor, a state-owned manufacturer of cigarettes and alcohol in Taiwan* Through-the-lens metering, a feature of cameras capable of measuring light levels in a scene through their lens...

 logic chips and quite often Vactrols, photoresistor opto-isolator
Opto-isolator
In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is "an electronic device designed to transfer electrical signals by utilizing light waves to provide coupling with electrical isolation between its input and output"...

s devices used as voltage-controlled potentiometer
Potentiometer
A potentiometer , informally, a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used , it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on...

s in VCA
Variable-gain amplifier
A variable-gain or voltage-controlled amplifier is an electronic amplifier that varies its gain depending on a control voltage .VCAs have many applications, including audio level compression, synthesizers and amplitude modulation....

 and VCF
Voltage-controlled filter
A voltage-controlled filter is a filter whose operating characteristics can be controlled by means of a control voltage applied to one or more inputs...

 sections. The approximately 10ms rounded attack and 50ms release 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 Generators
  • 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
  • 299 Sili Con Cello Processor


In 2001, Buchla returned to the 200 series and released the Barber Pole
Barber's pole
A barber's pole is a type of sign used by barbers to signify the place or shop where they perform their craft. The trade sign is, by a tradition dating back to the Middle Ages, a staff or pole with a helix of colored stripes...

 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
Buchla 200e
The Buchla 200e is a modular synthesizer designed by electronic music pioneer Don Buchla and built by Buchla and Associates.- History :The 200e is based on the earlier Model 200 system. Many of the modules in the 200e series share similar functionality and layout with Model 200 modules, and...

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.
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