I decided to try something different and ordered a pair of Electro Harmonix EL84 / 6BQ5 Cryo + Matched Vacuum Tubes. These are certified by CyroSet for undergoing their Cryoset Deep Cryogenic Treatment to 300 degrees below zero (Farenheit) and holding them there for a minimum of 24 hours.
This is said to improve the overall quality of the vacuum tubes. The cost was not expensive so I thought I would try it, nothing ventured, nothing gained. So waiting for the tubes to arrive and will roll into the P-100
OK, so you may ask what is Cryoset? You can check them out at "Cryoset.com"
When I have a chance to try the tubes I will report more!