Darkglass Electronics - Designed to respect the natural character of your instrument while expanding exponentially the tonal possibilities. The Tone Capsule can be installed on any type of bass (active or passive).
Installing the Darkglass Tone Capsule in Ibanez SR675 | TalkBass.com
Darkglass Tone Capsule Paired with Aguilar DCB-M4 Pickup in Sterling StingRay Sub ( Demo & Review) - YouTube
Darkglass Tone Capsule Bass Preamp System Reviews | Sweetwater