Tube temperature for ARC Ref 6

On the 6550:
(5429748) UltraSonic Rx-50 Damping Instrument     $30.29 X 1 = $30.29

on the 6H30's (# for both REF6 and REF150SE)
(5429716) UltraSonic Rx-9 Damping Instrument     $27.95 X 11 = $307.45

@docknow .........  Thanks for the info...I guess if you used the UltraSonic Rx-9 for the Ref 150 and that did not need the Hal-O III for extremely hot tubes, that would be safe to say about not needing that for the Ref 6 power supply 6550 and 6H30 .... So i will order 7 UltraSonic Rx-9 dampers , 6 for the analog stage and 1 for power supply ( 6H30's) And 1 UltraSonic Rx-50 for the 6550 power supply. I was concerned about the power supply tubes and NOT using the Hal-O III for extremely hot tubes and having UltraSonic Rx - 50 and Rx - 9 melt . 

Hi folkfreak: Ask Ron at Marigo Audio to let you audition some of his 3mm white dots underneath the smaller tubes of your preamp. That's what I've been using.