Welcome to SDS Labs, I have been rebuilding the Quad Electrostatic Loudspeakers (Quad ESL) for over twenty five years. These loudspeakers are in many ways still state-of-the-art even more than 45 years later. I rebuild the original ESL's as well as the ESL-63's and newer Quads (988, 989, 2805, 2905, 2812, and 2912) to original performance or better. SDS Labs provides component rebuilds including power supplies and panels, as well as complete rebuilds of the speakers. My rebuilds restore aging or damaged panels to factory performance, repair and rebuild power supplies and input electronics. My aim is to restore your quads to original condition both sonically and visually. I also provide information on how to rebuild quads yourself for the ambitious.

In addition to quad rebuilding, I also often have rebuilt pairs of speakers available for purchase. Information is available on the Quads For Sale page

As well as Quad loudspeaker work, I also provide circuits for a few vacuum tube based audio components. These boards rebuild aging parts and bring your component back to better than original performance.

In addition to these two main aspects of my hobby/business, I also have some information on DIY speaker building. In the footer of each page is a link to my old "classic site" that has a bunch of old, stale, but still useful information which was cluttering up the core information which I provide.