Tube temperature for ARC Ref 6

I have a REF5se and had this concern when I first purchased the unit. Using an infrared thermometer I can get readings up to 156° which is mostly over the 6550. But in talking to the folks at Active Thermal Management, I was told that the 6550 would be equivalent to a 75 W lightbulb. And a little Googling and I found that the surface of a 75W bulb can reach 200 degrees. So ventilation is the best solution but if space is limited, ATM offers some very quiet fans. I have achieved a 45 to 50° reduction in temperature readings. As far as tube dampeners I haven’t tried anything other than the original ARC since last time I looked Stereophile had them listed as very good. I forget what classification the assigned, but it was enough for me to figure on keeping them. On a previous LS26 I experimented with some Silicone rings from Herbies and also some other, I don’t recall the brand but didn’t feel any advantage over the ARC standard rings. YMMV.

I use the Rx in my Ref 40 and have had no issues. The effect relative to the original rubber type dampers is to give greater control and tightness. You can hear more air and snap in the recording. I have them on all the tubes including the 6550

i did opt for the HAL-O III for my VTL power amps but they run much hotter

I use Ultra Sonic tube dampers on all the small signal tubes with great results; most noticeable is tighter bass.

  The reason not to use dampers on 6550's or other power tubes is to allow the tubes to present harmonics and overtones. New production power tubes are low in microphonics and don't need damping. However, I can see how a damper might be needed for some NOS tubes.

theo.....Thanks for that great info....Very helpful. I really would of thought those tubes would of ran alot hotter.                                                                 theo.... folkfreak......lowrider57.......I guess there will always be some kind of debate as to wether Herbies dampers improve the sound as to stock ARC dampers. I guess you really have to try them yourself and see if your ears hear a difference. At  about $250 for dampers is quite alot. At least Herbies has a 30 day money back guarantee. So with that said, i am curious to see or hear for myself. 

I recently put Herbies Ultra Sonic tube dampers on all the tubes in my REF6.  Unfortunately, I can't tell you what difference they made, as it occurred at the same time as the installation of a new set of tubes from ARC, plus pasting the tube pins and back panel connectors with Total Contact.  It all sounded much better when re-inserted into the system.