[Badas]

Didn't you have cables that were too close to the amp, making all your tubes noisy? Is there any other wireless interference in your house? Some types of tube may be more susceptible to noise than others.

At one stage I thought that might be the case. However it proved to be not the case. Everyonce and a while when I suspect interference I picked up my amp and went into my workshop and pluged it in. I don't play music but just listen to the amp/tubes. The noise continues.

Right now the Mullards have settled. After 1 hours use. But they come and go with the noise. My memory from last time is the Mullards are noisy for 30 minutes or so then they settle to be mostly quiet. That suggest tubes to me rather than interference. If it was interference wouldn't they be noisy continuously?

 

[adeadcrab]

I have an OTL amp that I would SWEAR was making noise with specific tubes; changing tubes would result in no noise, sometimes for days at a time.

It was damaged in transit, the chassis was dinged up and not standing up properly, one of the cables was cut up and damaged from shipping, resistors were bent out of shape.
Had it repaired and now it works great. NOS tubes sometimes crackle while burning in for a few days and then it's fine.
Could be your amp internals.

Send me a few spare pairs of your tubes and I will confirm if they make noise for me too 

 just kidding 

 

[Badas]

I have an OTL amp that I would SWEAR was making noise with specific tubes; changing tubes would result in no noise, sometimes for days at a time.


It was damaged in transit, the chassis was dinged up and not standing up properly, one of the cables was cut up and damaged from shipping, resistors were bent out of shape.

Had it repaired and now it works great. NOS tubes sometimes crackle while burning in for a few days and then it's fine.

Could be your amp internals.


Send me a few spare pairs of your tubes and I will confirm if they make noise for me too   just kidding :bigsmile_face:

I wish there was someone local I could lend the tubes to so I could confirm.

If it was my amp or interference then wouldn't the fault stay on a particular channel. If I swap tubes the fault switches sides.

I think I might just roll my amp over. Take off the underneath plate and take a look at the internals. Something just doesn't feel right. The Mullards are virtually quiet now. They certainly have a lovely romantic balanced sound. I would really like to use these. I wonder if Woo has made a cap change to the WA22?

 

[adeadcrab]

Do you always have just of the pair of tubes not work properly? Still worth going over the amp internals IMO.

 

[Badas]

Do you always have just of the pair of tubes not work properly? Still worth going over the amp internals IMO.

Sorry. I'm not sure what you are saying here? If you don't mind can you re-phrase?

I have a well respected audio shop near me that does a lot of tube amp repairs. I think I will take my amp in and pay them to inspect.

 

[adeadcrab]

Sorry,

Do you always have just one of the pair of tubes not work properly? If you switch tubes then the issue goes to the other side. I had the same issue, although eventually the noise started switching sides, and both sides at the same time.

 

[Badas]

  Sorry,

Do you always have just one of the pair of tubes not work properly? If you switch tubes then the issue goes to the other side. I had the same issue, although eventually the noise started switching sides, and both sides at the same time.

The faults or noise always seems to follow the tubes.
 
Let me explain. I have sets with just one noisy tubes and sets with both. The sets that are both noisy are not always noisy equally. One might be noisy and the other can be noisy and crackle.
 
If I have one quiet and one noisy and switch them around the noisy tube switches.
 
If I have a noisy tube and a noisy/crackle tube and switch then they switch also.
 
If one is quiet and the other noisy the quiet one never gets noisy. It remains quiet no matter what socket it is in. The noisy never gets quiet. also.
 
The faults follow the tubes. Not where they are plugged in. That is why I have not looked at my amp being at fault seriously. Everything points to the tubes being at fault themselves.
 
What could be at fault in the amp is the circuits not being as tolerable as others. Maybe Woo has made some sort of change and it reveals noise easier?????
 
Advolt. When was yours manufactured? Mine was purchased Sept 2014 and it would have been manufactured in August as it takes a while to ship here (New Zealand).
 
Another interesting point is that I have the Tung-Sol 7236. Which I purchased the set from Woo themselves. The 7236 is a lot more powerful tube. It has a lot more gain than the 6080. The 7236's are dead quiet. Not a tiny bit of noise. I would have thought if there was a fault with the circuit this tube would reveal it as it is adding more load. Yet they are quiet.

 

[mikoss]

I've cured tube noise by giving the pins a thorough cleaning. I use baking soda and water in a small dish, mixed to a paste, then carefully scrub each pin with a q-tip and the paste. Rinse and then also use rubbing alcohol on each pin with a q-tip if you like. Avoid getting the alcohol anywhere else. Rinse the pins thoroughly with water after.

If you see a dark residue on the pins, this method may help to clean them and resolve some noise issues.

 

[DavidA]

I've cured tube noise by giving the pins a thorough cleaning. I use baking soda and water in a small dish, mixed to a paste, then carefully scrub each pin with a q-tip and the paste. Rinse and then also use rubbing alcohol on each pin with a q-tip if you like. Avoid getting the alcohol anywhere else. Rinse the pins thoroughly with water after.

If you see a dark residue on the pins, this method may help to clean them and resolve some noise issues.

+1
I've also had good results with Deoxit, red color one for most metals and yellow one for gold pins.

 

[Badas]

I've cured tube noise by giving the pins a thorough cleaning. I use baking soda and water in a small dish, mixed to a paste, then carefully scrub each pin with a q-tip and the paste. Rinse and then also use rubbing alcohol on each pin with a q-tip if you like. Avoid getting the alcohol anywhere else. Rinse the pins thoroughly with water after.

If you see a dark residue on the pins, this method may help to clean them and resolve some noise issues.

 
 

  +1
I've also had good results with Deoxit, red color one for most metals and yellow one for gold pins.

 
I will give the baking soda a go. Thanks.
 
Pins are very clean looking. No harm in trying tho. I will give them a go on the Mullards. As really they are the only noisy tubes I care about. Most of the others I'm not excited about.
 
I don't have alcohol but I do have a can of contact cleaner. Can I use that? and do I rinse again after applying the alcohol / contact cleaner?

 

[DavidA]

The contact cleaner will work but the Deoxit is a thick liquid that really helps with bad electrical contacts.
When I have problems with batteries in flash light not getting end to end contact and the light is flickering using the Deoxit makes the problem go away completely, every time.
There is also a cleaner that Deoxit makes and it will make the pins look almost brand new but needs to sit for a while for it to work.
Good luck, hope that it clears up your noisy tube problem.

 

[Badas]

  The contact cleaner will work but the Deoxit is a thick liquid that really helps with bad electrical contacts.
When I have problems with batteries in flash light not getting end to end contact and the light is flickering using the Deoxit makes the problem go away completely, every time.
There is also a cleaner that Deoxit makes and it will make the pins look almost brand new but needs to sit for a while for it to work.
Good luck, hope that it clears up your noisy tube problem.

Is this the stuff?
 
http://www.listeningpost.co.nz/Products/Audio-Accessories-Adaptor-stereo-home-theater/Cleaning-Supplies/Caig-Laboratories-deoxit-contact-cleaner-rejuvenator-__I.82983__N.27756__C.55048
 
I'm very limited to what I can get here.
 
Some other stuff I can get locally:
 
http://www.fishpond.co.nz/c/Electronics/q/Deoxit

 

[Dogmatrix]

 
Is this the stuff?
 
http://www.listeningpost.co.nz/Products/Audio-Accessories-Adaptor-stereo-home-theater/Cleaning-Supplies/Caig-Laboratories-deoxit-contact-cleaner-rejuvenator-__I.82983__N.27756__C.55048
 
I'm very limited to what I can get here.
 
Some other stuff I can get locally:
 
http://www.fishpond.co.nz/c/Electronics/q/Deoxit
 

I use the wipes every time I swap tubes , even though they look clean there is always a little dark oxide on the cloth after
 
Also , might pay to check your voltage over or under can cause problems with tubes
I checked mine and found it was over 250v so I bought a small step down transformer which dropped it to around 230v
One of my 5998 tubes had a slight hum at 250 gone at 230

 

[DavidA]

 
Is this the stuff?
 
http://www.listeningpost.co.nz/Products/Audio-Accessories-Adaptor-stereo-home-theater/Cleaning-Supplies/Caig-Laboratories-deoxit-contact-cleaner-rejuvenator-__I.82983__N.27756__C.55048
 
I'm very limited to what I can get here.
 
Some other stuff I can get locally:
 
http://www.fishpond.co.nz/c/Electronics/q/Deoxit

Yup, that's it, the second site has package deal for the two different ones (red and gold).  I don't care for the aerosol, gets all over the place and can stain stuff.
I've also tried using the gold one on gold plated RCA connectors and sometimes there is a difference if the connectors haven't been touch for a while (2 or yrs).

 

[Badas]

 
I use the wipes every time I swap tubes , even though they look clean there is always a little dark oxide on the cloth after
 
Also , might pay to check your voltage over or under can cause problems with tubes
I checked mine and found it was over 250v so I bought a small step down transformer which dropped it to around 230v
One of my 5998 tubes had a slight hum at 250 gone at 230

My system is on a Belkin Pure AV power conditioner (pic of it on the bottom of the rack) and is set on 230v. So it should be good.