Buchla 248 'MARF'

A reissue of a rare and complex 1970s control voltage generator, once part of the Buchla 200 Systems, now made for Eurorack

Overview

The Buchla 248 'MARF' - officially the Multiple Arbitrary Function Generator - was originally a module in the Buchla 200 Series systems of the 1970s. It was scarce and complicated, and it picked up a mythical reputation. It has since been reissued as the Buchla 248t MARF for the 200t Eurorack format. It's a programmable control voltage generator, built to shape sequences, modulate parameters, and generate complex timing structures with precision. The "rare and mythical" reputation comes from decades of absence and whispered stories in modular circles.

The original 248 came out of Don Buchla's experimental West Coast synthesis philosophy. The reissue was developed over two years by the Buchla team. It keeps the core functionality of its predecessor and adds V2 modifications aimed at reducing CV jitter and improving compatibility with expanders. It is not a simple clone. It's a total redesign, so purists may argue about how faithful it is, but practical users appreciate the better stability. It's built for deep interaction, and you have to wrestle with its three-tiered programming system to get at it.

Specifications

Manufacturer	Buchla
Product type	Multiple Arbitrary Function Generator (MARF)
Output voltage range	0 to +10 volts
Quantized voltage range	divide the voltage range into twelve equal intervals
Compressed voltage ranges	+0 = a stage bearing this command now has a voltage output range of from 0 to +2 volts. +2 = +2 to +4 volt output +4 = +4 to +6 volts +6 = +6 to +8 volts +8 = +8 to +10 volts
Number of stages	total number of available stages (16 or 32)
External input ports	4 external voltages appearing at the external input ports marked A, B, C and D
Power requirement	Apply 10.0V

Key Features

Three-Level Programming Architecture

Programming the 248 'MARF' is an involved process, split into three sections. Level 1 handles basic output voltage levels and interval timing. That sets how long each stage lasts and what voltage it produces. Level 2 gives more granular control, with commands for output pulses, voltage behavior, operating mode, and time range. Here users decide whether voltages are quantized or continuous, sloped or stepped, and pick a source from internal or external inputs. Level 3 goes deeper, with control over output voltage ports, time multipliers, mode selection, and direct stage addressing. This layered structure makes the 248 less a plug-and-play module and more a compositional tool.

Quantized and Compressed Voltage Ranges

The module divides its 0 to +10 volt output range into twelve equal intervals, which gives precise chromatic control with voltage-controlled oscillators or other pitch sources. It also offers compressed voltage ranges that split the 10-volt span into five 2-volt segments: 0-2V, 2-4V, 4-6V, 6-8V, and 8-10V. These ranges are selected with command codes (+0 through +8) and confine output voltages to specific bands. That's handy for limiting modulation depth or restricting sequences to particular registers without external attenuators.

16 or 32 Stage Sequencing Capability

The 248 'MARF' has either 16 or 32 stages, which supports extended sequences and complex control patterns. That gives composers room to build evolving modulations or long voltage curves, well beyond standard 8- or 16-step sequencers. Stages can be addressed directly in Level 3 programming, which helps with non-linear sequencing and conditional voltage routing.

Four External Voltage Inputs (A, B, C, D)

Four external voltage inputs, labeled A, B, C, and D, let the 248 respond to other modules in a system. These inputs can act as control sources for voltage output, time modulation, or conditional logic within the programming structure. That makes the MARF a processor of control voltages as well as a generator, able to react to and transform incoming signals in real time.

Microprocessor-Based Redesign with V2 Enhancements

Many vintage reissues replicate the original analog circuitry. The 248t MARF is a total redesign built around a microprocessor. That enables the complex programming logic and precise timing that define its operation. It also adds a digital layer that some purists question. The V2 revision addresses CV jitter, a known issue in earlier versions, improving timing accuracy and smoothing voltage transitions. It also adds support for an expander module, plus various fixes and enhancements that improve reliability and functionality over the original V1 design.

Historical Context

The original Buchla 248 MARF was part of the Buchla 200 Series systems developed in the 1970s. These systems were known for experimental interfaces and non-traditional approaches to sound generation and control. The 248 was one of the most complex modules in that lineup, made for users who wanted deep programmability and generative control. Decades later, the Buchla 248t MARF was reissued as part of the 200t Eurorack series. The reissue was reportedly in development for two years, given the challenge of translating such a sophisticated design into a modern format.

Collectibility & Value

Original vintage units are exceptionally rare, with no documented original price or production numbers. The reissued Buchla 248t MARF sells new for $999.00. Used examples have appeared for sale and sold on platforms like Mercari Japan, which points to active collector interest. Calibration is noted as a critical step, and listings often emphasize that units are "freshly built and calibrated." Given the complexity and the V2 modifications aimed at reducing CV jitter, collectors and users tend to prefer updated versions. DIY builders have also taken on the design, with reports of individuals building and repairing the V1 version.