O Ring for Tube damper?
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O Ring for Tube damper?
Went to an auto parts store looking for an O ring hOokup. Found some black ones the guy said were heat resistant up to 1200 degrees. The question is if he knows for sure? Most I see for sale as actual tube dampers are red. And these look like plain rubber. I may try it and keep an eye on them but I wanted to see if anybody had any similar experience/melted rubber bands on tubes? Thanks!
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Re: O Ring for Tube damper?
mattymel wrote:Found some black ones the guy said were heat resistant up to 1200 degrees.
Consider that we often touch or wiggle or even pull the operating preamp tubes with our fingers when we troubleshoot and don't raise blisters. That says that you don't need 1200° O-rings. Nearly all the heat emitted by an amp comes from the PT, power tubes and a few of the resistors.
Most I see for sale as actual tube dampers are red. And these look like plain rubber.
Red is a more appealing color and sells better than black to people who are looking for mechanical damping rather than fluid sealing. O-rings come in dozens of materials and colors according to their uses. Neoprene, Teflon and Buna-N are widely-known trade names for a few materials and most of them are black. Here's a link to information from one of the benchmark companies making o-rings
http://www.parker.com/portal/site/PARKE ... ky=O-RINGS
I'm sure no preamp tube generates enough heat to affect any of the o-ring materials you'd buy from an auto parts or local industrial supply store. Find a couple that fit and get a couple thicknesses since the thin one may be enough or the thicker (heavier) one may be needed. The particular elastomer used is unimportant but the mass (weight) is what does the damping.I may try it and keep an eye on them but I wanted to see if anybody had any similar experience/melted rubber bands on tubes? Thanks!
KennyO
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Bigger is NOT necessarily better and too tight defeats the damping action you're installing it for. The elastomer is as important as the size so go by trial and error and, being a musician, play it and use your ears.
Any thickness between .080" and .140" should do fine. It should be tight enough that it won't move up or down when you move it or play the amp and that's not very tight. Position the o-rings at the point where the internal structure is in contact with the glass envelope. The lower one probably won't have any discernible effect and if the upper one doesn't seem to do much, add another of the same size there instead of changing to a larger one.
Remember that some tubes are noticeably microphonic and some are not. If the tube in there is not, drop the o-rings into your repair kit for a future tube that rings like a cracked bell. Of the microphonic ones, some are helped by installing o-rings and some are not. Once more, play it and use your ears.
KennyO
Any thickness between .080" and .140" should do fine. It should be tight enough that it won't move up or down when you move it or play the amp and that's not very tight. Position the o-rings at the point where the internal structure is in contact with the glass envelope. The lower one probably won't have any discernible effect and if the upper one doesn't seem to do much, add another of the same size there instead of changing to a larger one.
Remember that some tubes are noticeably microphonic and some are not. If the tube in there is not, drop the o-rings into your repair kit for a future tube that rings like a cracked bell. Of the microphonic ones, some are helped by installing o-rings and some are not. Once more, play it and use your ears.
KennyO
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