CIGARBUM Posted April 2, 2011 Share Posted April 2, 2011 Do the tube thingies, that is the little things that go over the tubes to assist in cooling or vibration, not sure. Do these have any value? Do they work? Thanks. Cigarbum Quote Link to comment Share on other sites More sharing options...
clermontcop Posted April 2, 2011 Share Posted April 2, 2011 Hey Cigarbum I think the correct term for them is called a cylindrical shield, I could be wrong though. In my opinion they do work, but im not to sure if they have any value. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted April 2, 2011 Share Posted April 2, 2011 They will likely work best if the tubes are very microphonic. They will help stop the vibration that causes distortion. I'm not sure how much they aid cooling. Quote Link to comment Share on other sites More sharing options...
Edgar Posted April 2, 2011 Share Posted April 2, 2011 If you mean tube shields, then about all they do is cause the tube to run hotter; see Fig. 6 in the first paper here. Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 2, 2011 Share Posted April 2, 2011 The only tube thingie I have experience with are the "Tubesox", an expanding elastic tube that slides over the tube. They have copper metal threads as well as elastic, probably to help control the temp. My tubes didn't seem a lot hotter, but I didn't measure and they probably were. The manufacturer probably should be consulted. I thought the sonic benefit in one preamp (CAT) was a modestly greater clarity, so I left them in until I sold the preamp. I recall that Ken Stevens specified the tubes they were OK to use on, and the ones to NOT put them onto. Jud Barber (Joule Electra) also specified which tubes they were OK to use on, but thought there wouldn't be any sonic benefit. Predictably, for his preamp, he was right. It's trial and error, YMMV. It's hard to find these, and things may have changed since I tried them over 10 yrs. ago. These are what I used to have: http://www.rayofsound.com/e_accessories.html Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted April 2, 2011 Share Posted April 2, 2011 As mentioned above, these are tube shields which are used to reduce hum in high level circuits (such as phono stages). They definitely make a difference in some, but not all situations. If the shields are spring loaded, they may help to reduce microphonics to some degree. Since they are used with tubes which only generate heat from the filament (which isn't much), tube life isn't affected to any great degree when they are used. The shields also affect inter-electrode capacitance to a slight degree which theoretically can influence the highs, but I've never been able to hear any difference. Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 2, 2011 Share Posted April 2, 2011 The Tubesox that I mentioned claim to reduce microphonics, and to control resonances in the tube's glass envelope. I thought they definitely did the latter. They are elastic rather than metal (except for the copper threads), and didn't affect hum IME. Quote Link to comment Share on other sites More sharing options...
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