tube damper help

I have used herbies and the stock dampers that come with audio research pre amps and both seem to work well;I asked Ralph from atmasphere what he prefers once in a thread and his reply was to stay away from tubes that are known to be microphonic if you can;good advice I thought.

I don't know specifically which compounding we used at work.
Here, however is a link to a site which shows 2 different silicon compounds with way different max temps listed.
I would say the higher temp one is to be preferred. At least for output tubes.

http://www.marcorubber.com/silicone.htm

My experience with o-rings tells me I would tend to avoid the silicon. While I doubt in home use you'd ever get one to weep, there is a binder oil as part of the compound. We used to put them in an oven at over 100c+ at very low pressure. They would weep out oil. We couldn't use them as sold to us for reasons completely unrelated to tube guys use as a damper. Later, we found a source for pre-baked rings and began using them.

My o-rings are the S1000 compound from Marco Rubber and they neither weep nor jump for joy.

:-)

David

Arm,
I stipulated that it would be Very unusual for this to actually happen. Fact is, Silicon O-rings have a silicon oil binder in them. Period. If you saw evidence of this on a preamp, it would probably be WAY too hot. Output tubes? I don't know how hot they get. You are more likely to see such oils on output tubes, but still and all, since I've never seen it noted, I'll have to call it a real long shot.

If I owned a tube amp......and felt the need for tube damping, I'd make sure I bought either Kalrez or Vacuum baked Silicon. Your gonna have to trust me on this one. We chased a contamination problem for months in a 'wafer fab'. A place making 'chips'. We knew everything but the cause. One engineer suggested the silicon O-rings as the cause. We baked some ourselves and collected a couple teaspoons of oil from the catch cup we fabricated. In all fairness, we baked maybe enough silicon rings for 100 tube dampers. But, when we used 'em, the problem went away like we flipped a switch.

In short, the oil is real, You will only see it if something is seriously wrong and WAY over heats. I may have OCD!

It was easy to hear the improvment that Herbie's tube dampers made on the power tube of my ARC REF 3.