Herbie's Hal-O tube dampener's on Calypso?

didn't mean to read you a lecture...

I beleive they offer some sort of trial period for these with money back policy. They are inexpensive even compared to some other less effective tweaks. I use them on all of the 6922 tubes in my ARC LS-15 pre and like the results. What they did in my system(at least that's what I heard) was the improvement in the separation of instruments in the soundstage. Making things a little more distinct and easier to identify. But as always, your system is your system and you may or may not hear an improvement. I think it also depends on the type of tubes used, so your results may vary. Try'em out and if not to your liking, I am sure they can be sent back. Search the web also you may find a review or 2. Good luck.

John, I don't think tapping on tubes is such a good idea. It's very unlikely that this is a proper way of finding the most microphonic tubes. You can probably end up damaging the tubes like that. Here is a pretty cool article about NOS tubes that I enjoyed reading - http://www.soundstage.com/tubeor/tube.htm

That's cool John. By the way, back to Herbie's hal-O damping instruments. I experimented with them in my pre-amp and found them to work best(improvement is most noticable) when they are installed at the very top of the tube. Installing them in the middle of the tube and things start sounding sterile. Towards the bottom of the tube the pre-amp sounds a little better than with hal-o rings in the middle of the tube but still not as good as it sounds when the Hal-O rings are installed at the top of the tube. How was your experience?