Tube dampers

[AnotherJohnson]

We had a thread recently where the potential importance of tube dampers was debated.

It was noted that some CJ products have them from the factory, and others don’t.

I was looking at Stereophile’s most recent recommended components list, and ran across this in a Class A sub list.

Audio Research Tube Damping Rings: $5 each
Damping rings for all AR products are now available to the public at large. They're made of a proprietary polymer material that converts kinetic energy to heat, and their improvements are not subtle, exclaims BJR: tighter, cleaner, deeper, more dynamic bass; more coherent transient attacks; crisper, more extended highs; plus "improvements in the reproduction of subtle gradations of low-level dynamics." Give 'em a whirl—the cost is minimal. (Vol.23 No.2, Vol.26 No.8)

And they appear to be a bargain compared to the Hal-Os.

Don’t get too curious about the kinetic energy conversion to heat. That is what all damping strategies do … including the wall absorbers that we place around our rooms.

[roberto]

We know the tubes are microphonic. The dampers make to have less microphonic problem. Just tap a tube without the o-ring and install an o-ring and tap again. You will notice how well the microphonic is damped. Also prevents to resonate.

[roberto]

We also know that valves (tubes) work with much energy. This energy might cause the valve to vibrate. The o-ring will diminish this unwanted vibration. It is wise to use the o-rings.

[AnotherJohnson]

It is almost Birthday Eve for Bobby. I send him warm wishes for good health and prosperity as he moves into the next year.

Bobby and I are too old to worry about many things. But perhaps we know something about wisdom.

It is wise not to waste money on exorbitantly priced tweaks.

It is wise to save something from every paycheck so that one day you can retire.

It is wise to buy low and sell high. Whatever money is made in a deal, the only part you control is at the buy. Circumstances and market drive the sell.

It is wise to think of others before you think of yourself.

It is wise to revere God.

It is wise to set a good example.

As for tube dampers, I still think that if you like them, you will LOVE the tube shields. And I still say that tube dampers are harmless, and may help in some circumstances where a tube is microphonic but otherwise good. Maybe someone is marketing green colored silicone dampers. The green would designate the fact that the damper extended the tube’s useful life.

It is wise to take hobbies and other nonessentials in moderation.

[roberto]

Thanks for the best wishes AJ, born in Xmas time is a blessing for me!

I would like to add to your great advices:

It is wise to listen to the masters.

It is wise to think why the river sounds too much? It is because there are big rocks that are coming too. In other words, if there is a lot of chat in the same theme, there must be a reason why this is.

Audio is a matter of liking. Also depends if you are a melomaniac or an audiophile. I think that I belong to be an audiophile. The melomaniac is a person who loves the music, but he or she does not care about the quality of the reproduction. He or she can enjoy the music in a little Bose or in a big system.

The audiophile is the person who really cares the quality of the reproduction of the music in the audio system. He or she choose with much care the quality of components of the entire system. They train their ears spending hours of listen to the music and sometimes the differences are so subtle, that it is difficult to choose what it is under test. Let your ears decide. If you can't hear it, don't buy it. If you can hear it, buy it.

[roberto]

This is very important:

What I do like, not necessary must be your liking and viceversa. I use the food as analogy. I might like garlic and you don't. I like a lot of garlic and you might like just a dash. There are a lot of way of seasoning the food. Same in the audio system. There are rules to follow with logic.

1) Use heavy gauge speaker cable. No 12 or 10 gauge for long runs. The brands? Let your ears decide. Same in interconnects. There are a lot of low price companies with great products.

2) Try to hear it, not what I am telling. There are many things what some audiophiles might talk about, and if you think it is just mambo jumbo, perhaps it is. Trust in your ears. They always tell the truth. If you can hear it, them that's the path.

3) Listen to live unplugged music. A live guitar, or a piano, a bass, a cymbals, percussion instruments, a sax...this is the truth.

4) happy listening!

[AnotherJohnson]

Melophilia and audiophilia both knock on the door of melomania and audiomania… both domains of the AR OCD.

Treat them when you recognize them with a healthy dose of the great literary masters of old … you know who - they are no longer required, or even recommended, in current courses on literature.

[AnotherJohnson]

https://www.walmart.com/ip/20PCS-Tube-D ... lsrc=aw.ds

About 2 for a Buck. Now to compare them to the 10 times more expensive AR, or, shudder, the even more expensive Hal-Os.

[AnotherJohnson]

And an even cheaper source

https://m.aliexpress.com/item/328178752 ... 114fdc433a

Dime each.

[admin]

I really wonder if there is any difference between tube dampeners that cost $20 or 10 cents a piece. At the end of the day, the concept is the same. A flexible material that adds mass and thus changes resonance frequencies of the tube.

[AnotherJohnson]

It is more about constraint than mass.

The mass is trivial. The damping layer constraining the glass is more important.

The energy generated in a small tube is tiny. These aren’t power tubes. The issue is microphonics. Better to choose tubes that are not microphonic.

[roberto]

My experience is that all tubes are microphonic in a certain way. Some are much much less than others, been made by the same company and same number. Some oscillates when they are warming up. I use the o-rings that are available at the tube stores. Tubedepot.com or thetubestore.com have them. Buy the kinda orange colour.

As AJ says, the tension that the o-ring keeps while the tube is hot is what it is important. I have seeing melted o-rings. Basically the ones that are used in the Audio Research goods. I never have seeing melted the ones that CJ use. These have a funny orange colour.

[AnotherJohnson]

O-rings melt. Audio Research silicone tube dampers do not.

If you’ve seen them melt, some idiot swapped them for rubber O-rings before you saw it. Or else the power tubes ran away, or the installation restricted air flow, and anyone else’s would have melted too.

In a guitar combo amp, the speakers and electronics are in the same cabinet, and the tubes are not audiophile grade tubes. Dampers and shields are necessary. I’ve got a lot of them here.

In an audiophile grade component with audiophile grade tubes, dampers are harmless and may help in some cases. Don’t obsess over this tweak. If you put them on and hear an improvement, that’s one data point, and what you’ve done is reduce microphony in a microphonic tube. You haven’t proven that tube dampers are always necessary or desirable.

And don’t go tapping your tubes to find microphony. Tubes are hand made, and the vacuum is necessary for their proper function. Tapping on tubes can accelerate their demise. If you don’t hear a problem during normal listening, don’t go looking for trouble. You may create some.

[roberto]

Yes, they do AJ, and it takes a lot of effort to take them off the tube. I will place a pic of these type of o-rings, with transparent look and the o-ring shape material is not round. Only in the Audio Research I have had this problem.

Anyway, I do think it is wise to have the o-rings on small tubes. These small tubes are the ones to be more microphonic.

[AnotherJohnson]

Here you can see typical specs, and even have them custom made for you in large lots, like Herbie.

https://catalog.monroeengineering.com/v ... ne-o-rings

Audio Research and McIntosh both make really nice stuff. They are technically competent and would not foolishly choose something as cheap as a tube damping silicone o-ring that was not up to the task. If yours are melting, someone has played a trick on you and swapped for rubber … or else there was excessive heat present for some reason of other failure.

Probably 90% of the folks who look at this forum are CJ fans, including me. But there are a lot of competently designed and manufactured products out there. We like CJ best … but Audio Research (as one example) is not built by morons.

[AnotherJohnson]

From the link above

“This elastomer possesses mechanical properties similar to Viton®, with the exception of its slightly lower compression set resistance. It is more suitable for sensitive applications where lighter compressive forces are applied to energize the seal. This core has a Shore A hardness of 70 but it also offers a broader operating temperature range of -80°F to +500°F. (-62°C to +260°C).”

Most small tubes run at glass temperatures well below 260C. In fact less than half that.

AR uses silicone dampers. The odds of melting the correct damper by normal operation of the device are somewhere between zero and epsilon. In a runaway condition, or in a situation where ventilation has been blocked, bets are off. But the loss of the tube dampers is small potatoes in those cases. FWIW, if the correct dampers melted, I’d not bother to scrape the tube clean. I’d toss it.

I’ll let this go at this point. I just hate to add another silly tweak to the long list of voodoo based audio theory that plagues this hobby.

[roberto]

AJ,
These Audio Research are not mine. My customers bring them to me for service. I don’t mind to do it. Usually are into 6922 tubes. The last one was a VT-200. And are factory o-rings for sure. Also the 6H30 in the VT-100 happened too.

As soon as another Audio Research comes for repair, I will take a pic. This could be because of material fatigue.

[AnotherJohnson]

https://forum.audiogon.com/discussions/ ... earch-ones

AR guys debate the dampers. The level of anal retentive behavior extends all the way to worrying about the spacing.

[roberto]

Some were transparent silicon...these are the ones that I am talking about. They do melt. Vintage o-rings perhaps.

[roberto]

I use them almost hitting the bottom of the tube. The ones that CJ uses. They are red to orange colour. I don't think that they harm the quality sound.
My ears do not detect any difference with or without them. But there must be a reason why CJ uses them.