Hi, I recently completed a Boot Hill 5E3 build and the amp sounded excellent for ~3 hours of playing then it started getting the humming/crackling/distortion as you can see in the video I made at the link below. I tried alot of the troubleshooting tips on this forum including: removed each preamp tube - still had same issue hum does not go away if i turn the volume pots all the way down tried poking around with a chopstick with no results plugged amp into other speaker to ensure it wasn't speaker issue The last thing i did was switch the 2 new JJ 6V6 tubes out with some old 6V6 tubes I pulled out of a Laney amp in the early 80s (probably russian) - when i did his the problem went away. What is weird though is the 2 new JJ 6V6 tubes have been used for several months in a stereo (to break them in) with no issues. Any idea what is going on here? I am still not convinced the tubes are the root problem but would be happy if it is lol.