The Art of Power Starving

or how to make dead battery music

It has been known since the early days of music electronics that electronic devices like radios, amplifiers and musical instruments somtimessometimes produce strange sound artifacts during power on and off.
Also, that battery-powered devices change their sound or even behave completely differently atwhen the end of their battery life.goes low.
A simple digital  squarewave oscillator makes a boring nasty beep sound. But when power starving is applied, strange chaotic noises and self modulations occure and the sound changes completely.
In recent decades, this has led to the development of instruments in the experimental music electronics scene that deliberately exploit this effect of “power starving”.
The insertion of a variable resistorresistor, between the (stable) power supply and a soundsimple generator, which can be a simpleCMOS oscillator, is widely used. This variable resistor, also known as a “dead battery potentiometer”, simulates the increasing internal resistance of a battery duringwhile progressivebeeing discharge.discharged.
This means that power starving can be set reproducibly, even with mains-powered instruments or instruments fitted with new batteries.
Alternatively,

solar cells were also used to power the CMOS oscillators , which we are currently studying.
Thus power starving could be controlled via adjustable LED lighting.

Experiments have shown that it canmakes besense musicallynot usefulonly to beadd ablea to"bad additionallybattery reducepotentiometer", but also make the operating voltage adjustable in the musically interesting range. For standard CMOS oscillators, which, in the digital world, are typically powered with a5..18V secondDC, potentiometer. the "magic range" is much lower, most often between 0.5 and 2.5V .
In recent years, the friends of the Kulturgüterschuppen have dug up this topic again and made new experiments.
It turned out that a real adjustable current limiter, aka constant current source (CCS), could further expand the sound space when “power starving”.
Finally, sound space. Typical current consumption for CMOS oscillators operated in the magic voltage range is just a few micro amperes, thus we wantedbuilt an adjustable current limiter from 0 to make50uA to generate even more chaotic and unstable noises.

The fun begins, when power starving is not only statically controlled by potentiometers, but made voltage controllable like in analog modular synthesizers. Now the 3power parametersstarving voltage,sounds internalcan resistancebe modulated by any modulation source, be it self modulation feedback, envelopes or low frequency oscillators and any combination with modular synth modules can be made. Multiple simple power starving oscillators can be patched to complex, neural network like, topologies for endless sound experiments.

Power starving is not limited to dedicated oscillators. In fact, any electronic musical instrument, from sound toys, circuit bended instruments to "Lunetta style" synthesizers is worth to apply power starving.  Circuit bending can even be made safer when applying power starving tricks : lower power supply voltage and/or current limiting voltagereduces controllablethe in additionchance to potentiometers.
Askill onlyan operatinginstrument voltageswhile <5Vshorting andpins currents of a few mA are required forduring the bending experiments. Lunetta synths already use same or similar CMOS oscillators, simpleso opampit's circuitsa arenatural sufficient.process to power starve them.