ELRAD published a successor to the Take Five card in the issues March , April and May of 1997. This card has both optical and coaxial in and outputs and is completely 'plug and play'.
The May article is not official. See the scans below for an "official" version. Since I made this page the whole ELRAD site seems to have disappeared. So the March and April articles are no longer on-line at the ELRAD site. But I made a copy :-).
Boards with the main chip already placed can be obtained via Ingenieur Buero Detlev Mueller. You even get the drivers on a floppy and the EEPROM chip. I had problems with a 33 MHz PCI bus and the UMC cache RAMs. Reducing the PCI speed to 30 MHz solved most of the problem (single sample errors).
A ready made improved version, the DIGI32, is sold at RME Intelligent Audio Solutions.
Voor Nederland: SFB Electronics
These companies carry also other digital audio products. Disclaimer: I have no relation to them.
A great source for semiconductor URLs is Gray's Semiconductor Pages