DYING BATTERY EFX

The first time I underpowered an analog audio circuit, I did it out of simple curiosity. I wanted to hear what would happen if I fed a device less voltage than it was meant to receive. That small experiment opened a door I have never really closed. Voltage starvation, or voltage sag, means supplying a circuit with less than its nominal operating voltage. Many analog devices react in wonderfully unpredictable ways when pushed into these uneasy electrical conditions. Digital gear usually just shuts down, so this remains mostly a distinctly analog playground.

Most of my circuit ideas begin on a breadboard, where every component can be shifted or swapped and nothing is too precious to risk. It is the perfect place to test how a design behaves when starved. The oscilloscope and circuit simulators helps, but it rarely captures the part that matters most to me. The beauty is in the way the circuit feels and responds when I listen, not just in the shapes on the screen.

During one of these sessions I was working on a six-band graphic equalizer built around gyrators. Instead of dropping the voltage across the entire circuit, I decided to reduce the voltage only to the op-amps responsible for shaping the EQ bands while keeping the input and output stages at full voltage. This approach preserved the overall gain structure while pushing the heart of the circuit into a fragile, unstable operating region. The results were instantly inspiring.

While experimenting with that EQ, I also introduced its internal feedback loop, and this is where the behavior became even more interesting. Under normal operating conditions, the feedback would simply reinforce certain frequencies or push the system toward self-oscillation. But with the op-amps voltage starved, they no longer had the headroom or current capacity to respond cleanly. The feedback demanded rapid amplitude changes inside the filter core, yet the reduced supply voltage had collapsed the slew rate and shifted the op-amps’ bias points. With so little voltage swing available, the op-amps began saturating almost immediately, feeding a clipped or partially slewed version of the signal back into the loop. Each pass through the feedback path intensified this effect, creating a kind of pressure buildup, as if the feedback were swallowing the remaining headroom and forcing the circuit to operate inside a tiny, shrinking space. Sonically, the result was a kind of crushed, grainy texture that reminded me of early 8-bit game consoles.

That experience made it even clearer how dramatically voltage starvation reshapes circuit behavior. Reducing the supply voltage affects several electrical parameters at once. Headroom collapses, so the circuit distorts earlier and more unpredictably. Op-amp bias points shift, leading to asymmetric, broken-sounding clipping. Current availability drops, affecting internal compensation currents and reducing effective slew rate, which makes transients smear or fold in unusual ways. Dynamic range shrinks, revealing gritty, touch-sensitive textures, and temperature or input level can influence the behavior far more than they normally would. The sound takes on a raw, unstable, glitchy personality.

By pushing only part of a circuit outside its normal operating range, I realized how useful voltage starvation can be as an experimental tool. It lets me explore the hidden behaviors and limitations of whatever circuit I am working on. I now test voltage starvation often when prototyping around the studio. It is a safe and flexible way to explore new textures without putting finished hardware at risk, and many of the sounds I discover during these sessions end up in my sample libraries. Long takes from these experiments become a goldmine for lo-fi distortions, unstable drones, crushed transients, and broken machine textures. These are the kinds of sounds that feel too organic, too chaotic, and too alive for most digital emulations to capture convincingly. There is something strangely beautiful about a circuit struggling to stay alive. It reacts differently depending on how hard you play it or how close it is to shutting down entirely. For experimental sound designers, voltage sag opens up a world of expressive, unstable textures that simply do not exist under normal operating conditions.

Of course, not every circuit responds musically to being starved. Some analog designs simply stop functioning once voltage drops below a certain threshold, and others simply do not sound that interesting at all. Digital devices, microcontrollers, and switching regulators are particularly unhappy when underpowered, so it is best to use this technique only with gear you understand or hardware you are willing to experiment on. Still, when used thoughtfully, voltage starvation remains one of the most inspiring and unpredictable ways to reveal the hidden character of analog circuitry.