Tube dampers?


My system consist of Shanling STP 80 and T200 cd player, I have been looking around for tube dampers and I found some o-rings and other types of dampers, dont know which ones will work better for my setup since my El 34 electro harmonix and WE 396A/GE 5670W have a metal type cage around them so I dont know if I will have enough room to play with when it comes to tube dampers. I did look into Brass, O-Ring and Herbies type of dampers however I dont know much about any of them. Any advise?

I've heard about ARC, Herbies, Mapleshade and other vendors, some cheap and some $$$ If you recommend a product please please provide me with a link so I can lookup the information. Not looking to break the bank but do some worthwhile improvements.

Thanks, Robert
chgolatin2
Another vote for Herbies. I use them on my Ref 2 mk1 and heard differenty sonics as you "roll" them up or down the tube quite easily. They also do not dry up so you can use them on your next tube change.
I suppose it is time to dig out the Herbies that came with the amp I bought here on audiogon. They are in the basement somewhere.
I tried using O rings on my pre. Didn't notice any change. After a while the tubes started to make a ringing sound so I removed them. I think I'll try some teflon tape as I have some on hand.
This is the first time I've tried any kind of tube damping.
I bought some Duende Criatura tube rings. for MY JD100 AND
DK VS1. It's an amazing diference in detail and bass control.I'm hearing things that i didn't hear before.