Delaying AR Generator.
This is a microcontroller based module that combines an Attack-Release Generator with a delay. It can be built in either +/-12V or +/-15V systems without any modification, and other than the pre-programmed microcontroller, uses no hard to find parts. When used with the expander from BMC003, it has voltage control over all of the parameters.
Here is a youtube video that
shows the basic controls of the module.
Here is a youtube video that shows a patch using external control voltages to get a "ball dropping" sound.
For complete descriptions of the way the module is used, download
this PDF file.
Panels are available for this project for $7. For more information on panels, see this page.
If you'd like to drill your own panel for this, you can use my guide. It's intended to be printed at 300 DPI.
Price for 1 board and 1 preprogrammed PIC is $16. They are currently in stock.