@1b1e65e2 @3f26518c @e82d9b81 @134318c2 

Also the frequency-responce differences between when the tubes are cold, and when the tubes are fully warmed-up, is measurable and noticable to trained ears. :D

One bass-player who was experimenting with different tubes, found a pedal that allowed the tubes to be changed.

He then tested it out with different transistors and was getting measurable differences, even with the same-spec transistors.

Also for nice tubes:

https://vimeo.com/14490689 :D