Available as an assembled Module and as a DIY project.
This Module is currently available.
PT2399 digital echo/delay module
Just your bog-standard echo module based around the tried-and-trusted PT2399 digital echo IC.
If you're looking for a voltage controlled, effects-laden monster then you're in the wrong place - on the other hand, if you want a nice, easy to use echo/delay unit then this will have you covered. Works well with audio signals (obviously) but can also do interesting things to control voltages providing you keep them under 5V, otherwise the PT2399 tends to distort in a rather nasty manner (of course, you may want that ...)
Two pots, one for delay and one for feedback, keep things nice and simple - just the job for adding a bit of depth to your patches without blowing a hole in your bank balance.