I always cringed when I heard the reverb springs in my '73 Fender Super Reverb bouncing around in the back seat or trunk of my car. I knew it wasn't seriously affecting the amp (I get my reverb from an effects pedal now) but to this day that sound still unnerves me while driving (yeah, I still use that same Super) - what a great buy ($300 new) that turned out to be 27 years later !