Got my order for 2 Raytheon 12AX7 tubes today: Super Reverb RI: Steps taken: Raytheon in V2 and V4 - Loud hiss\hum Raytheon-1 in V2 and Tung Sol in V4 - normal hum Raytheon-2 in V2 and Tung Sol in V4 - Loud hiss/hum Good harmonic test on Raytheon 1 Harmonic test on Raytheon 2 failed - no sound through the speakers Gently sanded the posts in Raytheon 2 but received the same results. Used the same tube in V2 in a Deluxe Reverb with no noticeable hum/hiss. At first I did hear it, but it went away after around fifteen seconds. Also, I did hear a harmonic when tapping it within the DRRI. Do these need to burn in at all? If so I'll let it go for a while, but since one is not producing harmonics when tapped I'm pretty sure it's bad. The hum/hiss was there whether the guitar was plugged into the amp or not. Strange that the same tube would work fine in a DRRI and not a SRRI.