Potential valve damping tweak

[johnm]

Hi folks!

Have read alot about the puported benefits of adding tube dampers to get that extra bit of performance out of one's system.

Would an appropriate gauge of heatshrink tubing be a good candidate for a tube dampener? I have some clear heatshrink sleeving here that would fit signal valves which I'm willing to try out so long as nobody think this'll cause any problems?

Cheers,

- John

[analog_sa]

You can try as long as the heatshrink covers only a small area of the valve. Otherwise it will affect heat dissipation. No idea how much heat can a heatshrink take before it starts smelling funny and melting. A safer idea is to use some instant silicon gasket maker.

[kevinkr]

I think I have to agree with analog_sa on this one, and I have to add that I have not found this technique to more than marginally effective. It is the components inside the envelope and particularly the grid structure that rattles around. Anything on the exterior will slightly damp vibrations over a pretty limited frequency range if at all.

I think it is largely wishful thinking and a certain amount of self-delusion that comes into play with these sorts of tweaks particularly when they cost a lot of money.. (I know- I admit that out of curiosity I have tried various commercial tube dampers, and can't say that any of them really worked - aforementioned delusions aside.)

I've found properly isolated sub-chassis to be helpful as well as increasing mass/damping a non isolated chassis - mechanical isolation between the component chassis and a typical shelf seems to do a lot more frankly.. Also isolating vibrating transformers mechanically from low level stages is a big help too.

You can try your idea with the heat-shrink tubing over a small area of the envelope in the vicinity of the micas and see if it does anything good. If the stuff stinks you'll have to come up with an alternative, but the experiment is almost free. (I assume you value your time.)

[rdf]

Originally posted by kevinkr
I think it is largely wishful thinking and a certain amount of self-delusion that comes into play with these sorts of tweaks particularly when they cost a lot of money..

Phono stages excepted in my case. My Sonic Frontiers rang like the Gong Show when tapped before adding Pearl Coolers. I won't claim the sonic skies opened afterward though.

[johnm]

Well in the end it turns out the heat-shrink tubing I had was just a little too tight to fit over the valve anyways - doh!!!

The Valve amp (a freshly built Dynaco ST70) rests on a wooden chopping board with rubber feet as it is so I guess it's already pretty well isolated.

Thanks for the replies though