For 6AS7G tube rollers here .....
Jul 10, 2016 at 10:42 AM Post #3,676 of 9,511
Just got my NOS Tung Sol 6AS7G and popped them in. I noticed that there was a lot of rattle coming from the base of the tube, more so than my Svetlanas. Is this normal?

And when I started the amp one channel in my headphones got struck by a loud pop! They seem fine though. I am leaving the amp on without any headphones connected at the moment.

I've had many Tung-Sols and Chathams, and most of them had a rattle. It seems to be more common in these brands (same tooling facility). I've never had a problem with the rattle. I even have a Chatham where the plastic base came completely unglued from the glass. Still works fine.
 
Jul 10, 2016 at 1:36 PM Post #3,677 of 9,511
I've had many Tung-Sols and Chathams, and most of them had a rattle. It seems to be more common in these brands (same tooling facility). I've never had a problem with the rattle. I even have a Chatham where the plastic base came completely unglued from the glass. Still works fine.


Hi hodgjy,

I understand. Is it normal with pops when heating up? I almost feel afraid one would get one when listening.
 
Jul 10, 2016 at 6:53 PM Post #3,678 of 9,511
Just found this:

"Arcing power tube socket

The B+ may be arcing across the surfaces of the output tube sockets themselves. This is often the case when an amplifier has a lot of dust and dirt inside it. In some cases, the arc can be started by a few seconds of playing without a load on the amp, which causes large spikes on the plates of the output tubes. Contamination of the tube socket surface can let an arc get started, and the arc itself burns the surface of a plastic tube socket body. This leaves a carbon residue in the path of the arc, burned remains of the trail of the arc; the carbon residue is itself somewhat conductive, so in the future, there is a ready made path for the next arc. You have to replace the socket if this is the case."

Could this have been the case? :confused_face_2:
 
Jul 10, 2016 at 7:58 PM Post #3,679 of 9,511
Just found this:

"Arcing power tube socket

The B+ may be arcing across the surfaces of the output tube sockets themselves. This is often the case when an amplifier has a lot of dust and dirt inside it. In some cases, the arc can be started by a few seconds of playing without a load on the amp, which causes large spikes on the plates of the output tubes. Contamination of the tube socket surface can let an arc get started, and the arc itself burns the surface of a plastic tube socket body. This leaves a carbon residue in the path of the arc, burned remains of the trail of the arc; the carbon residue is itself somewhat conductive, so in the future, there is a ready made path for the next arc. You have to replace the socket if this is the case."

Could this have been the case?
confused_face_2.gif

 
As I mentioned earlier, popping, creaking and pinging sounds are quite common with 6AS7G. These tubes have 2.5 amp heaters and they get very hot. And as the tube heats up, these are the sounds the interior metal parts make as they expand. And in my experience the 5998 is the noisiest of all.
 
Now, I have no knowledge regarding the physical condition of your amp, dust and dirt, and so on, but again, even in a squeaky-clean amp, these tubes are going to creak, groan and pop as they heat-up... and as they cool down. It reminds me of the sounds an automobile engine makes after it is turned off.
 
Again, my advice, wait several minutes for these tubes to heat up and stabilize. And then connect your headphones, relax and enjoy.
 
Jul 10, 2016 at 8:04 PM Post #3,680 of 9,511
As I mentioned earlier, popping, creaking and pinging sounds are quite common with 6AS7G. These tubes have 2.5 amp heaters and they get very hot. And as the tube heats up, these are the sounds the interior metal parts make as they expand. And in my experience the 5998 is the noisiest of all.

Now, I have no knowledge regarding the physical condition of your amp, dust and dirt, and so on, but again, even in a squeaky-clean amp, these tubes are going to creak, groan and pop as they heat-up... and as they cool down. It reminds me of the sounds an automobile engine makes after it is turned off.

Again, my advice, wait several minutes for these tubes to heat up and stabilize. And then connect your headphones, relax and enjoy.


Sorry,

I now understand that an "arc" is lightning, and none have occured to my knowledge. It should be as clean as they come, so you are probably correct in your assesment. Much obliged :wink:
 
Jul 11, 2016 at 8:55 AM Post #3,681 of 9,511
Hi hodgjy,

I understand. Is it normal with pops when heating up? I almost feel afraid one would get one when listening.

A few pops during warm up is normal as the materials expand from heat. If they continue for 30 minutes, then I'd consider a new tube. The pings won't hurt anything except your mind.
 
Jul 11, 2016 at 9:10 AM Post #3,682 of 9,511
A few pops during warm up is normal as the materials expand from heat. If they continue for 30 minutes, then I'd consider a new tube. The pings won't hurt anything except your mind.


Thanks hodgjy,

Did some more listening this morning, and no pops after 5 min when I did plug my headphones in. So all is good I presume.

One silly question, are the pops volume dependant, i.e. changes with the volume?
 
Jul 11, 2016 at 9:17 AM Post #3,683 of 9,511
Thanks hodgjy,

Did some more listening this morning, and no pops after 5 min when I did plug my headphones in. So all is good I presume.

One silly question, are the pops volume dependant, i.e. changes with the volume?

I guess it depends on the amp design--and I don't remember what my amps did with pinging tubes because it's been a while.  They were never loud at all, so I had no worries of any damage to my headphones or ears.  They were certainly no louder than listening volume of the music.
 
All vacuum tubes are microphonic, so they can pick up noise and transfer them to the headphones. Tapping the table can even transfer noise with some very sensitive tubes.
 
Jul 11, 2016 at 9:42 AM Post #3,684 of 9,511
I have three different sets of 5998 tubes
 
All three sets stop pinging after about 7 minutes in my amp.
 
If i use them fairly often, i may not have any pings or pops.......if they sit for a good while, I will have pings and pops for a few minutes.
 
Jul 11, 2016 at 10:25 AM Post #3,685 of 9,511
  I guess it depends on the amp design--and I don't remember what my amps did with pinging tubes because it's been a while.  They were never loud at all, so I had no worries of any damage to my headphones or ears.  They were certainly no louder than listening volume of the music.
 
All vacuum tubes are microphonic, so they can pick up noise and transfer them to the headphones. Tapping the table can even transfer noise with some very sensitive tubes.

Ah,
 
I think we are talking about different things here. The pings you mention I do not experience, it was more loud pops. Not something you would like to have in your ears. Note, this only happened when headphones was plugged in from the beginning, or plugged in too soon.
 
Jul 11, 2016 at 5:00 PM Post #3,686 of 9,511
  Ah,
 
I think we are talking about different things here. The pings you mention I do not experience, it was more loud pops. Not something you would like to have in your ears. Note, this only happened when headphones was plugged in from the beginning, or plugged in too soon.


That is usually power sitting in a transformer and getting the power discharged as soon as HP's are plugged in.
 
Try this and this is what I do myself. When turning off your system turn off your tube amp but leave the HP's plugged in and music feed into the amp. You will hear music playing even tho the amp is turned off. The music will get quieter and quieter. Do this for 5 minutes then pack up the rest off the gear. What you have just done is discharged all the power from the transformers and tubes. When you start up the next time you shouldn't have a problem.
 
Don't adjust the volume when turning off. Let it carry on playing.
When starting up have HP's plugged in from the start. Tube amps always want to have a output. Whether it is speakers or HP's.
 
Jul 11, 2016 at 5:19 PM Post #3,687 of 9,511
  Ah,
 
I think we are talking about different things here. The pings you mention I do not experience, it was more loud pops. Not something you would like to have in your ears. Note, this only happened when headphones was plugged in from the beginning, or plugged in too soon.

We may be talking about the same thing. It's common for tubes to make loud pops and pings that are audible in the headphones during warm up.
 
Jul 11, 2016 at 6:31 PM Post #3,688 of 9,511
 
That is usually power sitting in a transformer and getting the power discharged as soon as HP's are plugged in.
 
Try this and this is what I do myself. When turning off your system turn off your tube amp but leave the HP's plugged in and music feed into the amp. You will hear music playing even tho the amp is turned off. The music will get quieter and quieter. Do this for 5 minutes then pack up the rest off the gear. What you have just done is discharged all the power from the transformers and tubes. When you start up the next time you shouldn't have a problem.
 
Don't adjust the volume when turning off. Let it carry on playing.
When starting up have HP's plugged in from the start. Tube amps always want to have a output. Whether it is speakers or HP's.

 
[Bold above mine]
 
No! An OTL (Output TransformerLess) amp is very different than an Output Transformer Coupled amp such as the Woo WA22 . Yes, transformer coupled amps can be damaged if they are operated without a load. But it doesn't hurt an OTL at all.
 
In an OTL amp, the headphones are directly connected to the plates of the 6AS7, with nothing in between. Leaving the headphones plugged in from the start, the start-up surge can easily damage headphones. This is not just theoretical. It has happened. And repairing or replacing headphones can be expensive. 
 
So again, for those who own OTL amps, never turn the amp on or off with the headphones plugged in. And again, after turning the amp on, wait several minutes, until the output tubes have reached their normal operating temperatures and stabilized, before plugging in the headphones.
 
Jul 11, 2016 at 7:20 PM Post #3,689 of 9,511
 
 
That is usually power sitting in a transformer and getting the power discharged as soon as HP's are plugged in.
 
Try this and this is what I do myself. When turning off your system turn off your tube amp but leave the HP's plugged in and music feed into the amp. You will hear music playing even tho the amp is turned off. The music will get quieter and quieter. Do this for 5 minutes then pack up the rest off the gear. What you have just done is discharged all the power from the transformers and tubes. When you start up the next time you shouldn't have a problem.
 
Don't adjust the volume when turning off. Let it carry on playing.
When starting up have HP's plugged in from the start. Tube amps always want to have a output. Whether it is speakers or HP's.

 
[Bold above mine]
 
No! An OTL (Output TransformerLess) amp is very different than an Output Transformer Coupled amp such as the Woo WA22 . Yes, transformer coupled amps can be damaged if they are operated without a load. But it doesn't hurt an OTL at all.
 
In an OTL amp, the headphones are directly connected to the plates of the 6AS7, with nothing in between. Leaving the headphones plugged in from the start, the start-up surge can easily damage headphones. This is not just theoretical. It has happened. And repairing or replacing headphones can be expensive. 
 
So again, for those who own OTL amps, never turn the amp on or off with the headphones plugged in. And again, after turning the amp on, wait several minutes, until the output tubes have reached their normal operating temperatures and stabilized, before plugging in the headphones.

Yeah, I never turn off my amp with HP plugged in....Glenn OTL.
 
I always wait for about 10-15 minutes when using 5998 tubes....letting them warm up before plugging in my cans.
 
That may be a tad long...but I always error on the side of caution.
 
Jul 11, 2016 at 7:37 PM Post #3,690 of 9,511
   
[Bold above mine]
 
No! An OTL (Output TransformerLess) amp is very different than an Output Transformer Coupled amp such as the Woo WA22 . Yes, transformer coupled amps can be damaged if they are operated without a load. But it doesn't hurt an OTL at all.
 
In an OTL amp, the headphones are directly connected to the plates of the 6AS7, with nothing in between. Leaving the headphones plugged in from the start, the start-up surge can easily damage headphones. This is not just theoretical. It has happened. And repairing or replacing headphones can be expensive. 
 
So again, for those who own OTL amps, never turn the amp on or off with the headphones plugged in. And again, after turning the amp on, wait several minutes, until the output tubes have reached their normal operating temperatures and stabilized, before plugging in the headphones.


Geez. I didn't know it was OTL. Thanks for correcting me. Right you are.
 

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