What is it?

This board converts a STAX SRD-7 with only 230v bias voltage to an optimized SRD-7 Mk2 with a "Pro" 580v socket and improved sound quality.

Why did you make it?

Electrostatic headphones have a sound quality that cannot be matched by dynamic voice coil or even planar-magnetic designs. Even if you have high-end dynamic headphones, there is something about singing plastic wrap that is hard to match.

"Energizer" adapters that allow you to drive a pair of electrostatic headphones from a speaker amp are cheap and plentiful if you want to listen to 200-230v bias voltage designs that are 40 years old -- and these do have a stunning, revelatory quality as it is, but the more modern designs require 580-600v bias voltage which normally requires an up-front investment of at least $300USD in addition to the cost of the headphone. Which is an unreasonable burden on the newbie.

As a music lover and nerd, I want to help people who don't have Clevelands to drop on a whim to get a sense of what is possible with head-mounted audio. A few Benjamins for the headphones and energizer at most! Plug them into a speaker amplifier you already have!

What makes it special?

To my knowledge, no similar product is available at this time.