nostr:npub1rv0xtc5q9n9ss7hyc4tand6myhyq6sp7r49ucfnywkhyfxpjhaes2wxuyz nostr:npub18un9rr8ffghh3q6d9d0fsuncxqx3d0lxc2s3amxlle9fz8cahxas2mzn38 nostr:npub1aqkehqwg0ghfe0c3spqskyuunvrrfqf5lwmwmh96vue9t27gja3s6ym25r nostr:npub1zdp33shl69xr0uq3x8n5gsjykq9upycwh6nqm02c3f6x0frrn0dq42vqv8 

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