Tube Dampers!?

Hi everyone

Has anyone had experience with tube dampers? If so what warranted their use? Do they really help with the sound quality improvement? Is this just a snake oil kind of thing?

Lastly who are the quality makers tube dampers?

I've seen them range in price from $1.89 for 2 dampers to up to $25

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380149870736&ssPageName=STRK:MEWAX:IT

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350323850081&ssPageName=STRK:MEWAX:IT

Here was a nice set that I saw from another lounge. Really nice but kind of expensive.

http://herbiesaudiolab.net/index.htm

Thanks in advance. JD

I've used them on my Sp3 and honestly couldn't really distinguish any audible difference.....