Synthetica (Digital Audio)

Positive. Negative. Positive.

With the advent of the transistor the world had changed. In some ways the humble triode is, in the opinion of this author, the most important invention of the 20th century; an invention that in many respects paved the way not only generally into the following century, but one that gave rise to countless new industries, fields of research, invaluable technologies, and seemingly endless possibilities.

The transistor

A transistor is a switch with three terminals: apply a source of current to the input terminal and nothing happens, but apply another source of current to the gate terminal, and suddenly the input current can traverse it through to the output. Simple? Indeed. Exceedingly simple, but it took a fair few years to get to the transistor by means of tireless research and useful predecessors, perhaps the most prominent of which was the thermionic valve (vacuum tube), the grandfather of the transistor before its eventual miniaturisation. While you can still buy a single transistor that is most certainly visible to the naked eye, most transistors these days are literally microscopic… and there are many of them. A typical integrated circuit can contain as few as about eight of these arranged as various logic gates, or as many as a few million.

Apart from fascinating research on universal Boolean algebra by the likes of Henry M. Sheffer who proved that all Boolean logic is definable by a discrete series of NAND operations (greatly simplifying Bertrand Russell’s work in propositional logic), it had become a sport of sorts, the relentless race down to the bottom, in a manner of speaking, to pack more and more transistors into an ever-decreasing volume. Richard Feynman famously said that “there is plenty of room at the bottom”, referring to the amount of usable space at the microscopic, nay, nanoscopic level, unimpressed as he was with what, at the time in the mid-20th century, constituted a pinnacle of microengineering that resulted in the printing of the Lord’s Prayer on the tip of a needle.

And indeed, there is plenty of room at the bottom, although space is ever-increasingly at a premium at the scale of the modern transistor, with ever-more-prominent issues surrounding heat dissipation and cross-inductance, the latter being used successfully to compromise various computer systems in recent years. With microprocessors composed of several millions of transistors switching on an off at billions (yes, billions) of times per second (yes, per second) with sizes ever smaller, now measuring seven nanometres (yes, nanometres), our thirst for computational power, hyperbolically perhaps but nonetheless, rendered a thermodynamic cost such that put us in serious thermodynamic debt, and physical reality started knocking on the door to collect.

Internet of Things

However, not all was lost, and what we have come to realise is that we do not necessarily need all the power in the world inside every microprocessor, that we are just as able, if not more so, to use scaled-back microcontrollers to see to our desired computational aims. Dubbed as a “maker revolution”, perhaps the 4th industrial revolution, the Internet of Things (IoT) gave a platform to low-powered microcontrollers and systems-on-chip, which despite their unassuming computational power, are seeing real-world applications in nearly every branch of engineering… including audio.

And so this is where my interests lie.

With the advent of the transistor, its eventual miniaturisation, and subsequent optimisation, the world of audio had changed. Now, more and more prominent are homebrew synthesisers, the DIY performance controllers, the wildly imaginative single-board-computer effect processors for every conceivable instrument, and in the slightly more conservative view of this humble author, possibilities for sound design, audio routing and near-real-time processing, and ad-hoc programming. Even a simple microcontroller with a humbling set of only 800,000 or so transistors is giving us the logical tools to take on the job of designing our own technology, if we so choose.

Within the scope of my own practice as a technician and live sound designer, I have used IoT and homebrew devices more often than I care to remember, and I do so more and more every year. Engaging with it on every level, from the lazy practice of simply downloading the printed circuit board (PCB) schematic and relevant code, to manufacturing and programming my own, there is no shortage of relevant, clever, and often commercially non-existent hardware that finds its place in microcontroller-aided design.

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