[bpiotrow13]

Can anyone help me identify what kind of tube this is?

Sophia Princess 274b.

https://images.app.goo.gl/jE9MUEXbyrWaHnZw5

I used to have it in woo wa22 and wa6se. Nice sounding and basically looks amazing.

 

[michael2v]

I had a BHC awhile ago and I know I have some good singles left that I will never use, let me have a look tomorrow, believe it or not, I think they are hiding in some kitchen cabinet my wife couldn't reach up to.

I would be happy to get in on this action if any manage to turn up.

I just acquired a lovely pre-owned BHC and swapped out the stock GE 6AS7GA with a garden-variety RCA 6AS7G and it is a big enough difference (in a really good way) that I'm curious to see where else this thing can go!

 

[HTSkywalker]

Can anyone help me identify what kind of tube this is?

A beautiful one

 

[N72826]

Hello everyone, I recently acquired a pair of Tung Sol 6AS7Gs on ebay. There are what appears to be 4 red/black "sleeves" at the base of these tubes that are loose. And when I say "loose" I mean the sleeves slide up and down. I'd like to know if this is normal or not, because I assume this isn't by design and is the reason I ran into the issue I detail in the next few paragraphs. I attached photos at the bottom of this post of the sleeves I'm referring to with the hopes of showing how they move, hopefully someone can shed some light on this.

So I plugged one of them into my BHC and after warming up for a little while, I noticed hissing/clicking and some very sensitive microphonic behavior just from the vibrations of typing on my keyboard which hadn't happened with any of the other tubes I tried. I began tapping the chassis/metal plate of the BHC to determine if it would get any louder/become a bigger problem as time went on. This decision turned out to be an extremely bad idea because doing so caused an extremely loud pop in the left channel of my headphones.

I took off my headphones immediately and turned off the BHC in order to swap back to the Tung Sol 5998. Surprisingly, neither my headphones or the BHC suffered any damage. I also didn't have any ringing/muffled hearing so I'm hoping that's a good sign.

I would just like to know exactly what could cause it if possible so that there's no possibility of it ever happening again. I was and still am genuinely shocked at how loud that was. I only tried one of the tubes I got, but they both have loose sleeves. So I am likely never going to plug either one of these tubes in out of fear for my own health.

Below you can see how the sleeves move up and down simply because of gravity, indicating how loose they are. The first two photos are identical, I just highlighted the things I am referring to so that someone more knowledgeable may be able to identifty exactly what they are because I just keep calling them sleeves.

 

[mordy]

Hello everyone, I recently acquired a pair of Tung Sol 6AS7Gs on ebay. There are what appears to be 4 red/black "sleeves" at the base of these tubes that are loose. And when I say "loose" I mean the sleeves slide up and down. I'd like to know if this is normal or not, because I assume this isn't by design and is the reason I ran into the issue I detail in the next few paragraphs. I attached photos at the bottom of this post of the sleeves I'm referring to with the hopes of showing how they move, hopefully someone can shed some light on this.

So I plugged one of them into my BHC and after warming up for a little while, I noticed hissing/clicking and some very sensitive microphonic behavior just from the vibrations of typing on my keyboard which hadn't happened with any of the other tubes I tried. I began tapping the chassis/metal plate of the BHC to determine if it would get any louder/become a bigger problem as time went on. This decision turned out to be an extremely bad idea because doing so caused an extremely loud pop in the left channel of my headphones.

I took off my headphones immediately and turned off the BHC in order to swap back to the Tung Sol 5998. Surprisingly, neither my headphones or the BHC suffered any damage. I also didn't have any ringing/muffled hearing so I'm hoping that's a good sign.

I would just like to know exactly what could cause it if possible so that there's no possibility of it ever happening again. I was and still am genuinely shocked at how loud that was. I only tried one of the tubes I got, but they both have loose sleeves. So I am likely never going to plug either one of these tubes in out of fear for my own health.

Below you can see how the sleeves move up and down simply because of gravity, indicating how loose they are. The first two photos are identical, I just highlighted the things I am referring to so that someone more knowledgeable may be able to identifty exactly what they are because I just keep calling them sleeves.

I am not familiar with this problem but it doesn’t look like the black base itself is loose.
It is definitely not a normal thing and it appears that both tubes are defective.
It is not worth risking your headphone drivers or damaging your amp - contact the seller and ask for a refund.
If the seller gives you problems, contact eBay for a resolution.

 

[N72826]

I am not familiar with this problem but it doesn’t look like the black base itself is loose.
It is definitely not a normal thing and it appears that both tubes are defective.
It is not worth risking your headphone drivers or damaging your amp - contact the seller and ask for a refund.
If the seller gives you problems, contact eBay for a resolution.

Thank you for your reply, I am planning on getting a refund.

And you are right, the base isn't loose. If the base were loose, I probably wouldn't have plugged it in at all.

In the first photo, if you look inside the tube at the very bottom, I highlighted the four small sleeves I am referring to in red.

 

[leftside]

A few things that are worth mentioning/repeating:

1) Let the amp warm up for a while before plugging in headphones.
2) Get some cheap sacrificial headphones. I have a pair from Amazon that cost $20. Plug these in first to test everything is "ok"
3) If you have a lot of tubes, consider a tube tester

 

[N72826]

A few things that are worth mentioning/repeating:

1) Let the amp warm up for a while before plugging in headphones.
2) Get some cheap sacrificial headphones. I have a pair from Amazon that cost $20. Plug these in first to test everything is "ok"
3) If you have a lot of tubes, consider a tube tester

Thank you for the suggestions. I wish I had taken this advice before risking my hearing and my headphones.

 

[g0ldl10n]

I took off my headphones immediately and turned off the BHC in order to swap back to the Tung Sol 5998. Surprisingly, neither my headphones or the BHC suffered any damage. I also didn't have any ringing/muffled hearing so I'm hoping that's a good sign.

You're lucky - this happened to me once but for me, I did have ringing/muffled hearing from the side (left as well) terribly, and the driver was blown - swear to god felt like I was hit with a flashbang in a movie scene or something.. horrible experience.

 

[mordy]

You're lucky - this happened to me once but for me, I did have ringing/muffled hearing from the side (left as well) terribly, and the driver was blown - swear to god felt like I was hit with a flashbang in a movie scene or something.. horrible experience.

I once blew a driver in a Beyerdynamic T1 from an explosive pop from a defective tube. Since then I have made it a habit to first plug in an inexpensive, sacrificial headset whenever I try out a new tube.

 

[g0ldl10n]

I once blew a driver in a Beyerdynamic T1 from an explosive pop from a defective tube. Since then I have made it a habit to first plug in an inexpensive, sacrificial headset whenever I try out a new tube.

That's always smart - I do not do this, although I should - but when it happened to me it was actually a driver tube I used a lot, and it was already warmed up and playing for the past hour or so, then huge pop and I saw it arc inside the tube when it happened, was very unpleasant. Needless to say, I do not use that specific tube anymore, although it tests fine

 

[N72826]

You're lucky - this happened to me once but for me, I did have ringing/muffled hearing from the side (left as well) terribly, and the driver was blown - swear to god felt like I was hit with a flashbang in a movie scene or something.. horrible experience.

Holy crap man I feel you. It's the worst because we weren't expecting a sonic boom in our eardrums

 

[g0ldl10n]

Holy crap man I feel you. It's the worst because we weren't expecting a sonic boom in our eardrums

Ya, I probably have hearing damage in that ear because of that, but at least as of now, I don't notice anything.. probably because I run mismatched tubes with my now mismatched ears

 

[HTSkywalker]

A damaged ear, a sold kidney, a wife knowing about a tube cost....This hobby is getting way more dangerous than I originally thought

 

[JackarlTwo]

Is there much difference between these tubes in terms of sound? I understand the QDD means it's from another factory?

https://www.langrex.co.uk/products/6080-cv2984-mullard-qdd-nos-boxed-valve-tube/

https://www.langrex.co.uk/products/6080-mullard-grade-1-valve-tube/