The above idea sounds good for the head. Another possibility I’ve used on occasion is to use one of those tension belts with a ratchet on it. Not quite as elegant but simple and you don’t need to make it.
This is certainly a departure from the typical Tiny Desk repertoire. I'm not really sure what to make of it, but overall have to say I kind of like it. Your opinions may, of course, differ...
Ooooh, Ampeg 8X10 stack. Plenty of pant-flapping heft. Yum-yum!
.....and most important of all, a rented backline so you don’t need to kill yourself schlepping the damn thing 👍