Do you have a tech practice?

I was listening to a podcast recently where they discussed the need for a tech practice. The argument was that they have choir practice, praise team practice, band practice, etc..., but less importance is placed on the Audio/Visual component of the church service.

For a typical service, we will have 10 volunteers and 1 paid staff member who work behind the scenes. While I agree wholeheartedly in principle, it is practically impossible to get a volunteer staff to give up a night to practice.

Do you have a tech practice? Are all the volunteers required to attend?