Silicone tube rings

[krellmk]

[FONT=Verdana, Arial, Helvetica, sans-serif]Silicone tube rings or whatever rings are often used to suppress resonances. They not only dampen the resonance, but do make the sound un-tube-like and less harmonious. [/FONT]

 

[AllenB]

Do you try replacing your speakers with a dummy load and sweeping a high level signal through them to find the squeaks? It's interesting you find this as the frequencies involved are often in the low kHz.

 

[kenpeter]

If you are going absurd with rings, why stop at silicone?

 

[DF96]

Silicone tube rings or whatever rings are often used to suppress resonances.

Do glass envelope resonances have much effect on the metal electrodes inside?

They not only dampen the resonance, but do make the sound un-tube-like and less harmonious.

I guess that may depend on what exactly you mean by "tube-like" and "harmonious".

 

[Miles Prower]

[FONT=Verdana, Arial, Helvetica, sans-serif]Silicone tube rings or whatever rings are often used to suppress resonances. They not only dampen the resonance, but do make the sound un-tube-like and less harmonious. [/FONT]

Never tried 'em myself, but I would suppose this would be more apropos to guitar amps where microphonic tubes in close proximity to the speaker might add some desirable "tone" to the sound.

Not sure what "un-tube-like" sounds like.

 

[JonSnell Electronic]

If there is any truth in the claims of improved 'ringing' rejection, surely the millions of valve amplifiers, that have been made for many years, would have them fitted as standard. Especially in the 50's and 60's when perfect noise rejection was the ultimate in fidelity.
Snakeoil and let's make loads of bucks from the suckers, comes quickly to mind here!

 

[billshurv]

Valves ARE microphonic and there have been many solutions to dealing with that. Tube dampers are at least cheap.

 

[miklos]

if they are microphonic ,than they are deffective

 

[billshurv]

erm, based on what?

 

[miklos]

simple logic, tubes are not manufactured to be microphonic, if they are than they are deffective

 

[billshurv]

clearly you have never tapped a working tube amplifier with a pencil then. All tubes are microphonic to some degree or other. Some types much worse than others.

 

[DF96]

Yes, all are microphonic to varying amounts. Not sure how a ring on the outside will damp vibrations on the inside, but I guess it won't do any harm.

 

[Miles Prower]

if they are microphonic ,than they are deffective

Not defective, just cheap. The 6BQ7s that have series connected heaters, the ones with a thin filament between cathodes, ring like bells. These are by their construction, cheaper versions. Microphony wasn't a problem, given the original design purpose: Small signal, VHF amplification to 300MHz. Of course, I avoid these like the plague when I use 'em for non-standard, audio applications for which they were never intended, and audio isn't even mentioned in the spec sheets (though the 6BQ7 makes an excellent cascoded LTP).

Furthermore, all components are microphonic to one degree or another. I did a TRF xcvr project where all 100db_v of gain occurred in the audio subsystem. With that much gain, its op-amps and transistors made for noticeable and annoying microphonics, especially when the volume was too high. Nothing you can do about it besides trying to minimize the effect with good, solid construction practices.

 

[miklos]

In old times manufacturers used suspended sockets in for example reel to reel tape recorders to keep the mechanical noises , like motor vibrations generated ones away from the input tube, but those where almost exclusively pendodes with more electrodes and a bigger construction (EF86 or EF804). Today nobody uses anything else than triodes ,like the ECC83 or ECC88, much smaller electrodes and the later one with frame grid. And yes, if you put enough gain on your dinner table, it can be used as a microphone, some secret organizations using this technique with great success.

 

[trobbins]

Some extra info on microphonics in link - there are ways to tame the beast if you need to tame it for starters - I hadn't seen the condom style before (which may rub off that Mullard label )

http://dalmura.com.au/projects/Microphonics%20in%20valves.pdf

 

[Vincent77]

simple logic, tubes are not manufactured to be microphonic, if they are than they are deffective

Wrong. Computer and some industrial tubes were manufactured without anti-microphonic structures, because it didn't matter and it was cheaper.

Other tubes have mica dampers to reduce the vibrations. For example, the ECC88 has internal mica dampers, while the industrial version E88CC / 6922 does not, and is more microphonic - some users prefer a little microphonic reverb...