Tube coolers?

Thanks everyone for the advice. I am trying to place a pair of 6NS7s in a space where there is only about 3-quarters of an inch to 1 inch from the top of the tube to the shelf above. (The rack is open on all 4 sides, though.) So I will give the Pearl coolers a try and see what happens, and try a fan later if I need to.

I am not sure how much heat 6NS7s generate, as I have not used them before. (I have some 12AU7s in a headphone amp that are pretty cool, so I was hoping the 6NS7s were cool also.)

Herbies tube coolers are very nice. I use them in all my equipment to get rid of heat from my tubes.

Http://www.herbiesaudiolab.net

And he and his wife are nice people to boot...Can't beat that and his prices.

I ran across this old booklet while looking into the subject of tube coolers.

Very interesting reading about tube reliability, but fairly technical. It does seem to suggest that cooling the glass is very helpful, but only mentions blowing air on them as a strategy. It's amazing how much has probably been forgotten about tubes :)

Thanks again for that, and especially to Auxetophone for that great book! I really appreciate that great find.

Has anyone found that the Pearl PCF or Herbie's Tube coolers/dampers have helped extend the life the tubes they have used them with? I'm just curious.

Also regarding Gundam91's post about putting a ground wire on each of the Pearl PCF tube coolers. My tube amp has a ground lug in the rear. Would I connect the wire from the tube cooler to the ground lug? I'm thinking I would need to connect the wires from each of the coolers to some other metal chassis.