The story of an early Melbourne synthesiser

By Melbourne Electronic Sound Studio

Transaudio Procase 6 by TransaudioMelbourne Electronic Sound Studio


Transaudio was a short-lived electronic music instrument manufacturer based in Melbourne, Australia. Between the years of 1972 - 1976, Transaudio produced several unique handmade synthesis systems, examples of which live in the MESS Studio. Each of these machines was produced in extremely limited quantities and as such are incredibly rare examples of early Australian design and manufacture of electronic sound instruments.


In the 1970s electronic music was emerging from the academies and institutions, and infiltrating the popular consciousness. Synthesisers, once colossus machines that graced the hallways of academia, were making their way into peoples homes and musicians' studios.

Manufacturers like Moog, Roland, Korg, Serge and Buchla among others were making great progress with everything from wall-sized modulars to more portable and affordable devices. EMS in London had a particularly big impact on the development of electronic music in Australia due to various confluences that you can read about in the story of the VCS1.

International 4600 (1973) by Electronic Today InternationalMelbourne Electronic Sound Studio


Transaudio's attempt to design electronic instruments in Australia at this time coincided with Trevor Marshall’s design and commercialisation of the ETI 3800 and 4600 machines, and Tony Furse’s design of the QASAR 1 in Canberra. In this sense, Bryan and Marshall and Furse were pioneers in Australian synthesiser manufacture and design.

Started in Melbourne by electronics enthusiast and businessman Bruce Bryan in 1973, with technical and design assistance from Jim Sosnin, Transaudio produced just a handful of machines from 1973-76. The company was a short-lived attempt to start a uniquely bespoke Australian brand of patchable analogue instruments made to order for Australian artists and institutions. In this three year period the company manufactured two flagship 6 oscillator matrix pin bay systems; the Pro Case 6 and the System 6.

Transaudio Procase 6, Transaudio, From the collection of: Melbourne Electronic Sound Studio
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The Transaudio Procase 6, one of only two 6 oscillator systems that the company built. This one was restored in 2013 by the original sequencer designer, Jim Sosnin. It is in great working order and available for public use at MESS.

Transaudio Procase 6 by TransaudioMelbourne Electronic Sound Studio

Pro-Case 6

The Pro-Case 6 was a comprehensive machine for its time. Putting aside its rarity, it remains an impressive instrument by contemporary standards for those artists working with subtractive synthesisers. Let's look in some more detail at its features.


The machine derives its name from the 6 core oscillators you can see here. Each module produces a wide frequency range, from very low rates found in LFOs (Low-Frequency Oscillators) to above 20kHz, which is beyond human hearing. Each module could also produce basic sine, triangle and square waves, which could be further manipulated via the shape control.


4 filter modules are the heart of this subtractive system. Each filter is switchable between low-pass and high-pass, a feature not found on EMS's comparable machines, such as the EMS VCS-3.

Envelope Generators

3 envelope generators allow for further modulation of the sound. Each generator can function in a single or looped mode and may be triggered by the built-in sequencer, the envelope follower, or randomly.

Output Amplifiers

4 output amplifiers provide the final mixing stage for all sound before heading to the instruments audio outputs. Also included are send and return lines for external effects such as a delay or reverb device.


A distinctive feature of this machine is the large matrix patch bay. Rather than using audio cables to interconnect modules in the device, this patch bay does the same thing by inserting a pin at the junction between two connections. 


Here the yellow pin is connecting the output of oscillator 1 (VCO, horizontal row A) to the input of filter 1 (verticle column 11). Rows are generally outputs, and columns are inputs. NB: It is hard to tell how many battleships you may or may not sink using this method.


Unlike the EMS VCS-3 machines, the Transaudio ProCase had a built-in 10 step sequencer to create repeating musical phrases or rhythmic patterns. Its signals can be sent to any other part of the machine.


The machine also has a collection of utility modules that can variously generate useful sounds and/or shape control voltages and display information. These can add further depth and complexity to the sounds the instrument can generate.


Lastly, we have a series of additional controls for some of the machine's functions. There are also controls for input signal amplifiers and a pitch to voltage converter, which attempts to detect any signal's incoming pitch and turn this into a voltage. 

Custom Built

Each of the Pro-Case series were powerful machines made to order and comprised similar components.

Robin Fox demonstrates how to create a basic patch on the Pro-Case 6.

Robin demonstrates how to use the Pro-Case 6 with a Roland TR-909 drum machine.

There is an example of an extended improvisation on this machine at the end of this story.

David TolleyMelbourne Electronic Sound Studio

David Tolley

The Procase 6 (pictured) was commissioned by David Tolley, a musician and sculptor who played a vital role in the experimental music community in Melbourne for decades. 


The instrument featured extensively in many of his live electronic music performances from 1976 well into the early 1980s. Purchased by MESS director Robin Fox in 2013, the instrument was restored by Jim Sosnin and is now available for public use at MESS.

Swappable System by TransaudioMelbourne Electronic Sound Studio

3 Oscillator Modules

A set of three 3 oscillator modular synths were designed and built by Jim Sosnin as teaching tools for the newly established LaTrobe Music Department - a radical department established by composer Keith Humble in 1975. 

Swappable System by TransaudioMelbourne Electronic Sound Studio

3 Oscillators

These machines were designed as teaching aids, but are powerful machines in their own right. They are very similar in functionality to the EMS VCS-3 synthesisers. Only 3 units were produced, all by hand as custom builds.

Discarded History

Here we can see the 2 machines that live in the MESS collection. All 3 machines were discarded in a dumpster when the Latrobe music school was closed in 1999. They were rescued by Melbourne artist and music librarian Michael Munson.


The heart of these machines is these 3 oscillators. Each has separate tuning (fine) and shaping (sine,  square, shape & ramp) controls. Each module generates a wide range of frequencies from below to above human hearing.


These two Low Pass filters are used to subtract frequencies from the oscillators. The sound of filters particularly filters moving across the sound (aka sweeping) is one of the most recognisable sounds in electronic music.

Envelope Generators and Amplifiers

Here we have the envelope (trapezoid) generators and the VCAs (Voltage Controlled Amplifiers). In concert, these two devices provide the shape of the sound in time also called articulation. They determine how the shape of the volume works over time.  

Ring Mod and Slew Limiter

Here we have the basic controls for the Ring Modulator and the Slew Limiter. The Ring Mod is used to inter-modulate voltages to add complexity to waveforms. The Slew Limiter is used to smooth out voltages and is often used to create pitch gliding or portamento effects.


In the centre, we have a meter for reading voltages (both DC and AC, hence a switch to select), as well as the power switch and power LED. We also have a noise generator that produced a range of random voltages.


The system uses scientific style banana plugs to interconnect the various modules of the machine. On this machine, each cable needs a resistor built into it, so the cables have to be customised for use.


We are very fortunate to have these two machines in the MESS collection given that these important pieces of sonic history were almost lost to us. The machines have been restored and are in good working order.

The company formed when Bruce Bryan met Jim Sosnin in 1972-1973. Jim had been Keith Humble’s chief technician at Melbourne University from 1971 and was responsible for installing the Synthi 100 (alongside Tristram Carey of EMS). During that installation process, Bryan had been keenly interested in what was going on. In an interview with Sosnin, he describes a situation where ‘Bruce seemed to be around a lot, I’m not sure why, but he was definitely interested in what was going on and was asking a lot of detailed questions about the Synthi 100.’

Transaudio 3 Oscillator Box Transaudio 3 Oscillator Box by TransaudioMelbourne Electronic Sound Studio

Transaudio Swappable

Another Transaudio machine turned up in late 2017 after spending decades under someone's stairs. This machine was a complete one-off. It is the only machine of its kind to exist. One of the first systems Transaudio built, the system was called the ‘swappable’ and was also commissioned for the fledgling LaTrobe university electronic music studio.

Transaudio 3 Oscillator Box Transaudio 3 Oscillator Box by TransaudioMelbourne Electronic Sound Studio


As with vintage Moog modular machines and contemporary Eurorack systems, this instrument was designed so that modules could be replaced and substituted for custom configurations. 


Here we have the two oscillator units with each offering slightly different functionality as can be seen by the control dials and signal outputs.


These two filter modules while looking similar offer different yet complementary functions. One is a low pass filter (VCF-LP) and the other is a high pass filter (VCF-HP).

Envelope Generators

Here we have two envelope generators, used for time-based waveform functions. Typically these would be connected to an amplifier to control how the volume of sound behaves over time.

More Oscillators

An additional pair of oscillators, similar to those in the case directly above.

Noise & Metering

This module generates random waveforms (noise) and also has a meter that is used as a utility for measuring and observing voltage behaviours.

Twin channel VCA

Here we have two twin channel voltage-controlled amplifier modules (VCA). These are a very basic yet essential part of any synthesiser or other electronic sound generator/processor. 

Slew Limiters

Lastly, we have voltage-controlled slew limiters. These modules can apply a ramp to a sudden change in voltage. These are often used to generate gliding and sliding voltages, used in pitch and filter sweeps.

Spare Modules

There are another 4 modules spare with this system that are not in a case. 2 oscillators, an amplifier and a slew limiter.

Swappable System by TransaudioMelbourne Electronic Sound Studio

The Demise

Sadly, the company had a limited window of operation due to their failure to deliver the custom instruments in a timely manner. He describes driving out to Mooroolbark (an outer suburb of Melbourne) and basically meeting Bryan in a spare bedroom of his house to discuss the desired design.

Transaudio 3 Oscillator Box Transaudio 3 Oscillator Box by TransaudioMelbourne Electronic Sound Studio

Dream Machine

As time went by Duffield kept paying incrementally for modules that didn’t arrive after having already paid a hefty deposit. Finally, Bryan stopped answering the phone and when Duffield drove out again to check on the progress of his dream synth, Bryan was gone. Given how much money had been invested Duffield launched an investigation and legal proceedings in 1976. Bryan was located and came to Melbourne to finally deliver the instrument.

Transaudio Procase 6 by TransaudioMelbourne Electronic Sound Studio


Unfortunately, it was incomplete and was not delivered with a sufficient number of pins to be useful. Disappointed and annoyed, Duffield describes how the machine became a doorstop in his studio. 

Despite the challenges faced by the fledgling company the machines are still working and sounding pretty wild!

MESS co-director Robin Fox performs an improvisation on the Transaudio Pro-Case 6.

Credits: Story

With thanks to Jim Sosnin and Andrew Duffield for their contributions to this story.

This MESS project is supported by the Victorian Government through Creative Victoria.
Photographs by Kristoffer Paulsen.

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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