Available as an assembled Module and as a DIY project.
This Module is currently available.
Dual Delay w/Feedback Network
The CASCADE DELAY is a dual PT2399 design. This module consist of 2 PT2399 chips, Delay A and Delay B. Each delay section consist of its own parameters - Delay time, feedback and feedback into the opposing delay’s input allowing each delay to feedback into each other.
CV control over delay time is also onboard with a selectable switch to control the delay time over both delays or just delay B, leaving delay A set to its knob setting.
These merchants probably sell this module. Huh?