Introduction A Sovtek EL84 power pentode tube I was working on my Vox AC30 clone that I built in high school, around 2009-2010, trying to figure out why I always had an oscillation issue when I turned the master volume up too far. Investigating the power amp side of the circuit revealed that I had incorrectly connected some of the grid-stopper resistors. I removed the tubes from the sockets so I could solder on the socket terminals without risking any damage to the tubes while they were in place, only to realize that the tubes were so stuck in their sockets that 2 of the 4 tubes cracked in their base.