T4 Opto-attenuator Info
T4 Page
DIY Gear Links
If you're into building your own gear, here is a list of resources you might find helpful:
Prodigy Pro Forum - the grandaddy site for all things DIY. This site has lots of information on DIY pro-audio projects ranging from beginner to exotic and obscure.
Mouser Electronics - One of the biggest electronic components distributors in the US. They stock a lot of the parts used in the projects discussed on the Prodigy Pro forums.
Digi-Key Electronics - Another big electronics parts distributor and another key supplier for components used in the projects discussed on the Prodigy Pro forums.