Bad Chatham 2399?

[Aeolus Kratos]

Hi everyone,

I've just been joining this awesome Bottlehead Crack community for a very short time, since my first troubleshooting topic : http://www.bottlehead.com/smf/index.php/topic,4451.msg41786.html#msg41786

The problems back then was the bad stock 6080 and 12AU7 tubes. So I ordered a Tungsram E80CC on Ebay and the Tung-Sol 5998 power tube on Radio Electric Supply ( vacuumtubes.net ). And they finally arrived just a moment ago. The NOS E80CC is good, but what I pulled out from the big box is a Chatham 2399 instead of a Tung-Sol 5998 and there are some little broken glass inside the tube. There are 3 pieces of glass, 2 are very tiny and 1 is a little bigger.

I insterted it to my Speedballed Crack and let them warm up, then I plugged my HD650 and I heard some 'sound' coming from the right channel AT THE SAME TIME I was plugging the HD650 into my Crack. It's not noise or hiss, it's just a 'ting' sound. But when the HD650's jack is fully plugged, it's back to dead silent. I'll let them have some time to burn in and the sound is simply amazing. But this really confuses me

I have several questions:

- As far as I research, the Chatham 2399s are identical to the Tungsol 5998s, but I have read somewhere that there are some differences between them. Can anyone confirm if the 2399's and 5998's sound identical or not?

- Despite the fantastic sound, I'm really confused about the 3 little broken glass pieces inside my Chatham, can they do harm to my Crack and my HD650?

- There are some measurements on my Chatham's box:

Gm: 16.15 / 16.70 ( 104% )
Plate current: 95.7 / 112.6 ( 94% )
Brand: Chatham
Construction: Black plate - 2399

Are they good or bad? Sorry for this silly question, but I really have no idea about these concepts

-  Lastly, what is the proper way to burn-in tubes? I just turn the Crack on and let the tubes 'burn', or do I have to play the music and plug a headphone into my Crack?

Thanks in advance! I'm totally a newbie here. Forgive me if there is any mistake. My English is not so good

[adamct]

2399 and 5998 are the same. Minor differences depending on when produced, but I wouldn't worry about it.

The glass pieces are odd, but if the tube works, I wouldn't worry about it. Glass isnt conductive, a d if you arent shaking the tube, it should be fine. If it will bother you, you can try to exchange it for another.

The "ting" sound was just microphonics. The tubes were picking up vibrations from when you inserted the plug and amplifying them.

The tube values look fine.

Best regards,
Adam

[2wo]

Small bits of glass in a tube are not uncommon. Nothing to worry about if the tube works well otherwise...John

[Aeolus Kratos]

2399 and 5998 are the same. Minor differences depending on when produced, but I wouldn't worry about it.

The glass pieces are odd, but if the tube works, I wouldn't worry about it. Glass isnt conductive, a d if you arent shaking the tube, it should be fine. If it will bother you, you can try to exchange it for another.

The "ting" sound was just microphonics. The tubes were picking up vibrations from when you inserted the plug and amplifying them.

The tube values look fine.

Best regards,
Adam

Hi Adam,

Thank you very much for your help! I'm relieved now

As for the 'ting' sound. Is there any way to solve this problem? Can tube dampers prevent the tubes from vibration, so the microphonics will be gone?

Thanks again!

Cheers,
Kratos

Small bits of glass in a tube are not uncommon. Nothing to worry about if the tube works well otherwise...John

Here are some pictures of my Chatham 2399 with pieces of glass:

The red circle indicates where I think the glass pieces comes from

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm6.staticflickr.com%2F5469%2F9465982868_5bb3f007c4_b.jpg&hash=ed52d2bea153f1057af98b42bfdae5d56393a30f)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm4.staticflickr.com%2F3676%2F9465982200_674df6c1ff_b.jpg&hash=d19a978daa10dc2d6139f34af5676f6ec68a9ac1)

And these are the broken glass, there is one fairly noticeable piece :
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm4.staticflickr.com%2F3692%2F9463198565_6887983014_b.jpg&hash=e8f0ce6e1f06f841d09f5bd7f88b0771523cea7c)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7292%2F9463197381_1dfb41cc62_b.jpg&hash=5abf5b3e624ff816f81379a9410ebce361708ff1)

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm3.staticflickr.com%2F2833%2F9463196275_71d06d8286_b.jpg&hash=52c5335a37b38a3907a3b892bff754d0e788f7ea)

[adamct]

Could be from there...in any case, I still don't think it's a problem. If you want to contact the seller and try to exchange it, you certainly can, but you might get one that tests at lower values than the one you have.

As for the microphonics...you only hear them when you insert the plug in the Crack, right? I think you said that as soon as the plug is fully inserted, it's back to being silent, right? If so, I wouldn't worry about microphonics, that is totally normal. You can try tube dampers if you like, but I don't think they will stop some mild ringing when you insert and remove the headphone plug.

BTW, others will jump in if I'm wrong, but I think the 12AU7 is the more likely culprit for the microphonics.

Best regards,
Adam

[Aeolus Kratos]

Could be from there...in any case, I still don't think it's a problem. If you want to contact the seller and try to exchange it, you certainly can, but you might get one that tests at lower values than the one you have.

As for the microphonics...you only hear them when you insert the plug in the Crack, right? I think you said that as soon as the plug is fully inserted, it's back to being silent, right? If so, I wouldn't worry about microphonics, that is totally normal. You can try tube dampers if you like, but I don't think they will stop some mild ringing when you insert and remove the headphone plug.

BTW, others will jump in if I'm wrong, but I think the 12AU7 is the more likely culprit for the microphonics.

Best regards,
Adam

Hi Adam,

I received my Chatham yesterday, but after a day working fine, my Chatham seems to have some problems today. I've recently noticed that there is some 'hiss' ( the 'oooooooo' sound or the high frequency sound ) coming from the right channel as I fully insert the plug. When I insert half of the plug, the 'hiss' comes from both channel ( because I read somewhere that if you insert half the plug into Crack, it turns out you will hear the right signal through both channels ) . The 'hiss' is constant regardless the volume. But when I turned to max volume, the 'hiss' became louder.

But the weird thing I figured out is that this problem does NOT always happen. Since this morning, I have turned my Crack on 3 times, and the problem only happened twice. The first time was in the morning, I got up and let the tubes burn in. The hiss appeared as soon as the tubes warm up. I let them run for 2 hours, and when I returned, the hiss was gone. The last time I noticed is when I was listening to my Crack tonight, it's silent when the amp started up. But after about 2 hours, this hiss appeared again. I feel like this happens randomly.

I'm pretty sure this is due to my Chatham, as this does not happen with my old 6H13C and the Tungsram E80CC

I think I would exchange my Chatham

Thanks a lot, Adam, your help is simply awesome.

Best regards,
Kratos.

[Aeolus Kratos]

There is one thing I've just noticed. When I replaced the Tungsram E80CC with my cheap old unknown 12AU7, the amp is back to silent. That means:

- Chatham 2399 + Tungsram E80CC => hiss

- My old 6H13C + Tungsram E80CC => silent

- Chatham 2399 + my old 12AU7 => silent

Now I really don't get it. Is it because of my Chatham or Tungsram? Or because of something else?

[Paul Birkeland]

The hiss could also be environmental (on the powerline).  Look for corelations between the hiss and things like fluorescent lights, computers, etc. that are powered on at the same time.

Glass bits inside the tube are no big deal, this is incredibly common.

-PB

[Aeolus Kratos]

The hiss could also be environmental (on the powerline).  Look for corelations between the hiss and things like fluorescent lights, computers, etc. that are powered on at the same time.

Glass bits inside the tube are no big deal, this is incredibly common.

-PB

Hi Paul,

Yes, you're probably right. The hiss has no longer happened for 2 days now. I guess that maybe some of my electric devices could be wrong.

I have contacted the seller of this tube, and they said the glass bits are just the defect and this happened in about 20%-30% of all the tubes. They are willing to refund or exchange a new tube for me, but I think I would keep it. The glass bits do not bother me very much

Best regards,
Kratos.

[Aeolus Kratos]

Hi guys,

Last night, I've experimented a problem with my Crack...again

I turned my Crack on and let the tubes warm up for about 10 minutes, then I plugged my HD650 into it. But when the music was playing for just a few minutes, there was a big 'pop' sound coming from the left channel ( it was like there is an 'explosion' in the left channel ). Then it was back to silent again and nothing happened after that.

My Crack killed my $5 headphone once when I tested it with bad tubes back then. Now I'm really afraid that what if would kill my HD650 too, I don't want to take risks again, especially with a $400 headphone

Any advice?

Best regards,
Kratos.

[adamct]

I had something similar happen to me once. It was a bad 6080 tube. I swapped it out and everything was fine.

[Aeolus Kratos]

I had something similar happen to me once. It was a bad 6080 tube. I swapped it out and everything was fine.

Hi Adam,

I was using the Chatham 2399 and the Tungsram E80CC when this problem happened. If they were bad tubes, I would

[adamct]

Why not try the stock tubes that came with your kit? That will at least help with troubleshooting.

Also, FWIW, I have an E80CC, too. I used it for quite a while and liked it. But ultimately it didn't sound better than my 12AU7s or 12BH7s, and Doc has said that it isn't ideal in the circuit, even if it will work just fine. So I went back to my Mullard 12BH7.

In any case, try the stock tubes.

[Paul Birkeland]

If you get popping, then no sound, there will be voltages that are off.

If you measure those voltages, then post them here, we can make recommendations that are more accurate than just general speculation.

-PB

[Aeolus Kratos]

Why not try the stock tubes that came with your kit? That will at least help with troubleshooting.

Also, FWIW, I have an E80CC, too. I used it for quite a while and liked it. But ultimately it didn't sound better than my 12AU7s or 12BH7s, and Doc has said that it isn't ideal in the circuit, even if it will work just fine. So I went back to my Mullard 12BH7.

In any case, try the stock tubes.

Hi Adam,

This is why I could not try the stock tubes:

I've just been joining this awesome Bottlehead Crack community for a very short time, since my first troubleshooting topic : http://www.bottlehead.com/smf/index.php/topic,4451.msg41786.html#msg41786

The problems back then was the bad stock 6080 and 12AU7 tubes. So I ordered a Tungsram E80CC on Ebay and the Tung-Sol 5998 power tube on Radio Electric Supply ( vacuumtubes.net ).

But other than that, I have several variants of 12AU7's and 6H13C's. I'll try to swap them.

You said that this problem happened to you once. How often did it happen? This is just the first time this happened to me, after a week the Crack was working perfectly.

Best regards,
Kratos.