[I right I]

I am getting the most annoying metal-on-glass noise out of the tubes of my WA6. I have the stock 5AR4 rectifier and 6GL7s from Woo. Has anyone used tube dampers? Any suggestions as to which ones are effective and which are not? I am contemplating using simple O-rings but I am vain about the look of my toys (at least I'm honest about it) and I would like something more "sexy". Ideas?

 

[Dubstep Girl]

Quote:

I am getting the most annoying metal-on-glass noise out of the tubes of my WA6. I have the stock 5AR4 rectifier and 6GL7s from Woo. Has anyone used tube dampers? Any suggestions as to which ones are effective and which are not? I am contemplating using simple O-rings but I am vain about the look of my toys (at least I'm honest about it) and I would like something more "sexy". Ideas?

 
like herbies tube dampers?
 
http://herbiesaudiolab.net/rx.htm

 

[atomicbob]

Does the metal on glass sound occur after 15 to 20 minutes past power on? Tubes exhibit thermal expansion as they warm up and it is not uncommon to get pinged during that time. Then again, some individual tubes are just plain noisy. Others can be pretty quiet. I bought a number of common 6080 / 6AS7G and 6922 for my WA3+, listened and graded them. A few were noisy with respect to residual hum and general noise after warm up.

 

[Silent One]

With my WooAudio WA 6 Special Edition, I switched to adapters to run 6SN7 tubes not long after purchase. No 6SN7; 7N7; 7AF7; 5U4G or USAF-596 ever produced noise, hum or other.
 
It wasn't until I acquired an OTL amp with Power tubes, that I began to experience hum, pop and ping. However, the drive tube and rectifier remain quiet...always.

 

[Yiannis1974]

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It doesn't sound like a tube issue if the problem won't occur under headphone listening.  
 
My guesses-- check your speaker wiring very very carefully.  My bet is you're shorting somewhere.  Check the banana plugs, too.  I ditched those ages ago and wired direct to the post.
 
If your speakers and wires and connectors are 100% perfect, then there's likely a bad solder somewhere inside the amp to the output connectors.  But eliminate all other possibilities first, because Woo QC has been notoriously great (and how often do we get to say that?).

Hello reeltime and thank you very much for your helpful suggestions. I actually checked the speaker connections and they are fine. I have a small integrated amplifier sitting on the side of the WA3 and I just connected my speakers there to test. I performed the test a number of times to make sure and indeed no problems at all with the speakers and the cables. I think I can safely rule out short circuit issues.
 
The Tubes have also been tested at a local hi fi shop and they appear fine....

 

[Yiannis1974]

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Are you RCAs new? I have heard of factory defects in RCAs causing noises like those to which you are referring.

Hi,
 
I have completely disconnected the WA3 from the sonos to see what happens. In other words, the only connections are WA3 power and speaker cable connections. The problem remains unchanged sadly. 
 
One other thing I have noticed is that the woofer cones move slowly in and out (quite a lot of travel). This happens immediately after power up and it continues thereafter. This appears to be a separate issue or it may be connected... who knows.
 
Speakers are Audioengine P4s by the way. No problems at all when I connect them to the Audioengine N22 or a Pro-ject integrated amp that I have sitting next to each other.
 
very weird.

 

[soullinker20]

Hi guys! what tubes can you suggest me for the WA7?
 
 
thank you!

 

[Yiannis1974]

I have finally contacted Jack and asked for an RMA. The WA3 is going back . I have the highest praise for the particular amp so I can only conclude I have been very unlucky. Cost to ship back: $40... Ouch

 

[musicman59]

Quote:

I am getting the most annoying metal-on-glass noise out of the tubes of my WA6. I have the stock 5AR4 rectifier and 6GL7s from Woo. Has anyone used tube dampers? Any suggestions as to which ones are effective and which are not? I am contemplating using simple O-rings but I am vain about the look of my toys (at least I'm honest about it) and I would like something more "sexy". Ideas?

I used to use the Herbie's halo rings but changed to the Duende Criatura rings and I like them better.
http://www.tubedepot.com/dctuberings.html
 
You can see them here in my tubes.
 

 

[ben_r_]

Quote:

I used to use the Herbie's halo rings but changed to the Duende Criatura rings and I like them better.
http://www.tubedepot.com/dctuberings.html
 
You can see them here in my tubes.
 

WTH? Someone please explain to be in physics or electrical terms how those rings "[size=x-small]considerably reduce microphonics, distortion and self-oscillation from audio tubes".[/size]

 

[reeltime]

Quote:

I have finally contacted Jack and asked for an RMA. The WA3 is going back . I have the highest praise for the particular amp so I can only conclude I have been very unlucky. Cost to ship back: $40... Ouch

 
Sorry-- it happens to all of us at one time or another.  Even Woo's lowest entry amps are quiet and shouldn't do what yours is doing.  They are great products (I've owned two and have had wonderful experiences with them).  Hopefully your turnaround is short!

 

[Todd R]

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WTH? Someone please explain to be in physics or electrical terms how those rings "[size=x-small]considerably reduce microphonics, distortion and self-oscillation from audio tubes".[/size]

http://en.wikipedia.org/wiki/Microphonics
 
Since the elements of the tube are in contact with the glass, dampening the glass can reduce the movement of the internal parts of the tube.
 
Try it next time you listen to a tube amp, lightly tap the glass with your fingernail and you should hear some sound come through the headphones (or speakers).
Next, put a tube damper or a high temp O ring or some other device on the tube and do it again. The sound from the tap will be much less. Some tubes will ring a lot more than others depending on brand, type and build quality.
 
You don't have to be tapping on tubes to hear microphonics however. Vibrations from music, transformers and other sources affect tubes. 

 

[john57]

tube amps can also benefit from a isolation platform as well.

 

[GrindingThud]

They increase the effective mass of the glass tube envelope, lowering the resonant frequency.  They also, because of both increased mass and plasticity, decrease the amplitude of vibrations of the glass envelope.  These effects can be substantial, especially in the face of a particularly sensitive tube.  I've have a couple tubes that were so microphonic they could pick up a voice converstaion (they were discarded even though they test good).
Quote:

WTH? Someone please explain to be in physics or electrical terms how those rings "[size=x-small]considerably reduce microphonics, distortion and self-oscillation from audio tubes".[/size]

 

[dminches]

Quote:

tube amps can also benefit from a isolation platform as well.

 
I have my tubed phono pre on a gingko cloud.  I can't say I know if the sound is improved.