Power sag for guitar EFX

Update 07/07/2024


I started making the dying battery effect in 2011 (by request for Christian Hand). Since then I have updated the design a couple times but the last version is was a complete overhaul of the circuit. Since then a lot of different companies have started offering some version of this effect.

I have not made any of these POWERSTARVE units available for sale in a while I figured I would share the latest circuit design. It is different than the Beavis dying battery or power sag that you most often see when searching for this type of effect. Rather than running the power through a small value pot (serious, that is all the old design is) I utilized a more complex (but still dead simple) variable power circuit using an LM317 regulator. Adding true bypass and an LED indicator really made the POWERSTARVE a pedal in its own right.

I have had great luck using the POWERSTARVE with transistor based effects. From fuzz to tremolo, if it runs on transistors you should give starving the power a try. You never what to expect but if you have ever had a pedal that sounded awesome with dying batteries, then this is the effect for you.


From Eric Johnson to Duane Allman, many select guitarists have utilized used and dying batteries to get the “best tone” out of their Fuzz Faces. There are stories of cigar boxes filled with old batteries, guitarists “auditioning” different batteries before a gig, and even sending techs around the venue to find old 9 volts. Tone chasers can be crazy, but it works.

Here is a clip from the Library Music Film talking about the use of dying batteries in effects on the song Confunktion by Dave Richmond.


2023 update of the POWERSTARVE circuit

While the original power sag design works well, I felt it left a little to be desired unless you were overclocking your effect with 12-18 volts of power. What makes the above design work well is that it is a variable voltage supply rather than a voltage divider. The divider design will get you lower voltages but I have found that most pedals do not react at all under 5 volts. However, you can always under-clock this device with less than 9 volts.

Of course, you can still overclock this design, too. It will get you around 3 volts of play up to 24 volts MAX input power. I would use a 50v 1uF for C1 if you plan to go up to 24 volts.

If you want one, I’ll whip one up for you. Contact me.

POWERSTARVE through the years


first power sag by POTAR 2011

This a must for any guitar player with an EFX fetish, simply plug this bad boy in between your power supply and your favorite EFX pedal to enjoy the sag. The pedal simulates the dying battery effect that can sometimes result in desirable clipping, out of place tones and general weirdness.

UPDATE: 12/16/11 –
These are built to order so case color and knob may vary. Be sure and look at the FOR SALE PAGE for a more current pic.

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