O-Ring Tube Dampers

shload · « **on:** 11 Apr 2003, 08:08 pm »

Anyone using silicone o-ring tube dampers on their equipment? Positive or Negative results. Thanks Joe

jcoat007 · « **Reply #1 on:** 11 Apr 2003, 08:19 pm »

I use Herbie's with great results.

http://herbiesaudiolab.home.att.net/

nathanm · « **Reply #2 on:** 11 Apr 2003, 09:35 pm »

Would O-rings melt I wonder? How hot does the outside glass get on an average tube? I'd like to damp the rectifier tube on my SE-9 as it makes a mechanical buzzing noise. If regular 'ol O-rings did the trick that'd be cool.

shload · « **Reply #3 on:** 11 Apr 2003, 10:12 pm »

Using silicone o-rings should be ok with the heat. Asking because I saw them on Ebay[/url]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=14974&item=3017993393&rd=1 . Found the rings online for about that price for a Qty of 50. Joe[/url]

nathanm · « **Reply #4 on:** 11 Apr 2003, 10:40 pm »

Probably could get those at a hardware store I'd imagine, and not mess with shipping. Just another option to consider. Although I am not sure how much the average O-ring is going for these days.

JoshK · « **Reply #5 on:** 12 Apr 2003, 12:49 am »

I used Halo tube dampers and I have to say I could not tell a difference before and after. If there was one it was so minor to be leagues less than cables which are a couple steps below a component change, IMO.

Jay S · « **Reply #6 on:** 12 Apr 2003, 01:40 am »

I use a Hal-o's on some of the tubes in my tube pre. I'm getting more today for the rest. Not too sure about the impact.

Here's what I can tell you about o-rings. I bought my Joule tube pre used, and there were o-rings on 2 of the tubes that had become rock hard due to age and exposure to heat!! I had a horrible time getting them off as I was worried about damaging the tubes.

Juan R · « **Reply #7 on:** 12 Apr 2003, 12:56 pm »

Where about the brass one , like from Mapleshade?

Herbie · « **Reply #8 on:** 16 Apr 2003, 06:04 pm »

I've used Mapleshade dampers in the past. The resulting sound quality is not bad, with only a very slight "brass" coloration to the music, but they are a hassle to use and are not adaptable to differences in tube diameters. Contrary to the manufacturer's claims, these brass dampers do not function as heat sinks, but act as dutch ovens, causing tubes to run considerably hotter than they should. The brass heats up and holds the heat, surrounding the tube with that heat while blocking the air-flow necessary for tube cooling.

BTW, Josh: There's nothing wrong with the fact that HAL-O damping instruments have little effect with your tubes---this means that your tubes do not suffer significantly from microphonic distortions, and that's a good thing!

Keep on enjoying the music.

Nelgan · « **Reply #9 on:** 16 Apr 2003, 06:20 pm »

I've had good results with Herbie's with some of the slightly microphonic tubes that I have. I love my Tungsrams, but they are slightly microphonic. The Halo dampers silenced them substantially.

MaxCast · « **Reply #10 on:** 16 Apr 2003, 06:21 pm »

I have to agree with Herbie. I have a pair and on one set of tubes they made a definite impact for the good. On another set of tubes I couldn't tell if it helped or not. For the money they are great to have on the tube.

JoshK · « **Reply #11 on:** 16 Apr 2003, 07:26 pm »

Quote from: Herbie

BTW, Josh: There's nothing wrong with the fact that HAL-O damping instruments have little effect with your tubes---this means that your tubes do not suffer significantly from microphonic distortions, and that's a good thing!

Thanks Herbie for the comment. Also I would say that honestly I didn't care if it added a whole lot or not, it was a cheap enough tweak to try out anway. I could see how it would work for some more than others.

nathanm · « **Reply #12 on:** 16 Apr 2003, 08:43 pm »

Here's a general question: Does tube microphony only affect the sound if the acoustic waves from the speakers are loud enough to be fed back through the air and to the tube, or does the microphonic nature itself cause a coloration regardless? For example, would you expect to see less effects of microphony at lower SPLs or if you were using headphones? So far in my tube experience the microphonics only became self-evident when the amp was physically struck. It was harder to tell if sounds through the air alone were being picked up.

I just bought some orange silicone O-rings from McMaster-Carr. Not super cheap, but in audiophile terms a mega bargain!

Hopefully I got the size right. The ones for the 12ax7s or similar diameter I got 25 rings for like 8 bucks. Not too bad. Hopefully it will damp the buzzing 5AR4. As far as the other tubes I guess I will have to wait and hear. Not expecting much though. Might look cool though. ?

Nelgan · « **Reply #13 on:** 17 Apr 2003, 03:39 am »

It depends on just how microphonic the tubes are. Highly microphonic tubes will be excited by power supply vibrations. I had one set of tubes that would start ringing when my preamp was turned on, and the ringing would intensify as long as I left the power on, with no music signal present at the inputs. An extreme example, but it does not take high SPLs to affect tubes prone to microphonics.

KKM · « **Reply #14 on:** 17 Apr 2003, 03:39 pm »

Also check out Pearl tube coolers, claims to extend life of the tube and tame some microphony.

TheChairGuy · « **Reply #15 on:** 19 Apr 2003, 04:05 pm »

I have nothing to compare to in either Herbie or other O ring tube dampers, but have been very pleased with a $.02 damper I read of on one site or another long ago.

A rope caulk top hat.

In hardware store, they are usually known under Mortite or Dennis brand names (usually in paint area), it is string rope caulk that is quite pliable. I think the package is $5 or so...but you'll only use 1/1000 of package. Can be used for so many other things, you won't mind.

Put a thin dime sized dab on top of the tube (small input tubes only as I would think large output tubes may overheat) and allow 'tip' of tube to peek thru 'hat'. Keep to only top of tube and use less not more if not sure.

Has improved every tube I've ever used it on - some dramatically. Probably the microphonic ones were dramatically, others less so.

I haven't noticed any shorter lifespan for any tube ...and I think I'm on 10 or 12 tubes now with it (none dead yet). Of course, some of you may like the 'sound' of tubes in natural state, so beware. It comes off easy enough if you want to remove it.

nathanm · « **Reply #16 on:** 19 Apr 2003, 07:40 pm »

I've outiftted my SE-9 with an array of silicone O-rings. Wouldn't you know it, the rectifier wasn't cooperating and making it's normal buzzing sounds. I think it got scared when it saw me coming and decided to behave itself. If you want a problem to go away just have TWO people try to observe the problem. I know this works with computers, perhaps it will work for audio as well?

Anyway, I think it made an improvement. The music sounds more orange now, with more bounce. Yet still firm. I'd say around 70 durometer or so. Asthetically it's a toss up. Perhaps black would be a better color, but I didn't have much choice.