Positive/Negative Reinforcement
Discipline depends on their age:
1) Positive
Kids. Leave dad's "precious" audio stuff alone and I'll give you $X.XX/day to do so. (Depending on your budget. Maybe after getting all that cool gear you have no money left over.) Of course, this leads them on a greedy capitalistic path.
2) Negative
Kids. Touch dad's "precious" audio stuff and he will touch one of your "precious" items. It will disappear for an amount of time you don't want to think about. Then again, you may be fostering years of counseling when they grow up.
Wait until you come home one day and your two year old daughter has extracted about 40 of your precious cassette archive tapes. She's had so much fun pulling the pretty tape out and playing with it.
Stashing all in another building with you with the only keys is the best solution so far.