Crack;Bottlehead OTL
Sep 4, 2023 at 2:56 PM Post #12,047 of 12,346
Replace the tube.
If you keep using this and a short happens u might burn up some other stuff...
Be safe, replace the tube....
What I would do is throughly clean the tube socket then replace the solder inside each tube pin. I have repaired several power tubes doing that. It is especially bad on Russian tubes but I have fixed Tung Sol 5998’s doing that. I then run them in a tube tester or a cheaper amp.

If you like I could examine the tube and replace the solder in the pins at no charge. PM me if you need my help, I can give you a list of folks here who would vouch for me. I run those tubes in amps I designed so even it it damaged one of mine I could repair it.😀

8F5D369C-3E42-4C12-A7ED-3DE132D2ADCC.jpeg
 
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Sep 4, 2023 at 7:51 PM Post #12,048 of 12,346
FWIW, I'd replace the tube. It sounds like that's where the problem lies. If you get a new tube and the problem goes away then you'll know
it's the tube for certain. If the problem remains then you'll have to look elsewhere in the amplifier itself. Moreover, if you keep using this tube
it may damage your amplifier so why risk it? Best of luck!
The Bottlehead forums are very helpful. The Crack specific forum is likely your best resource.
 
Sep 4, 2023 at 8:04 PM Post #12,049 of 12,346
Wondering if anyone can help diagnose an issue I ran into recently with my Crack..

I bought a second-hand Bottlehead Crack amp w/ speedball about 8-10 months ago and have been thoroughly enjoying it with my HD650's. About a week ago though, as I was listening to it the sound on the right side of my headphones cut out. I immediately inspected the amp and noticed that only the left side of the power tube (a TungSol 5998) was lit. I turned the amp off, waited a bit, then turned it back on. Both sides lit up just fine and I continued listening until eventually the same thing happened again. Now only the left side ever lights up when powering on and I only have sound in one channel.

Would I be safe in assuming that the tube is done for? Or could be something else (like a faulty tube socket) causing this? I did go in and redo all of the solder joints around the tube socket but that didn't seem to help.

Just wanted to see if anyone has experienced something similar before I go ahead and spend big bucks on a similar quality replacement tube.
As people are mentioning, it is most likely the tube. However you need to be sure, right? Get the cheapest stock 6080 tube you can get, which should run you only a dollar or two to test the amp. If you try this new tube and have the same issue with only one side working there is potentially a problem with the heater wiring, in which case you'll need to identify what and where.

If the new tube works fine it would seem to be an issue with your 5998. Before scrapping the expensive tube I'd take @Paladin79 up on his offer and see if he can help you get it working again. I'd do these things before buying a new 5998.
 
Sep 4, 2023 at 8:12 PM Post #12,050 of 12,346
As people are mentioning, it is most likely the tube. However you need to be sure, right? Get the cheapest stock 6080 tube you can get, which should run you only a dollar or two to test the amp. If you try this new tube and have the same issue with only one side working there is potentially a problem with the heater wiring, in which case you'll need to identify what and where.

If the new tube works fine it would seem to be an issue with your 5998. Before scrapping the expensive tube I'd take @Paladin79 up on his offer and see if he can help you get it working again. I'd do these things before buying a new 5998.
5998’s have been known to have pin solder issues, I do not just reflow the old solder, I remove it and replace it with silver solder after using rosin flux to thoroughly clean the inside of the pin. @DenverW is absolutely correct about making sure the tube is the culprit. 007F0F43-E163-41DD-80F8-E073E3619CCB.jpeg
This is an octal ready for new solder.
 
Sep 4, 2023 at 8:21 PM Post #12,051 of 12,346
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My Bottlehead Crack, I did all cabinet and copper work. Dual single gang pots and VU meters in the front, all inputs and AC switch on the back.🤪
I do not want to reach around hot tubes to reach a switch or pots.
 
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Sep 4, 2023 at 8:26 PM Post #12,052 of 12,346
E75D488A-0BFF-4A56-ACDA-6198046ACED2.jpeg

My Bottlehead Crack, I did all cabinet and copper work. Dual single gang pots and VU meters in the front, all inputs and AC switch on the back.🤪
I do not want to reach around hot tubes to reach a switch or pots.
Makes me jealous whenever I see your work!
 
Sep 4, 2023 at 8:28 PM Post #12,053 of 12,346
Sep 4, 2023 at 8:47 PM Post #12,054 of 12,346


My Bottlehead Crack, I did all cabinet and copper work. Dual single gang pots and VU meters in the front, all inputs and AC switch on the back.🤪
I do not want to reach around hot tubes to reach a switch or pots.

Bottlehead Crack on STEROIDS!! 🙄. Really like your personal interpretation of the BC and the top of the case as well as the other mod's are very tastefully
done. 👍
 
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Sep 4, 2023 at 8:50 PM Post #12,055 of 12,346
Bottlehead Crack on STEROIDS!! 🙄
I wanted plenty of room in the cabinet for modifications. I used the original power transformer and not a whole lot else.😁
 
Sep 4, 2023 at 8:52 PM Post #12,056 of 12,346
I wanted plenty of room in the cabinet for modifications. I used the original power transformer and not a whole lot else.😁
Always better to have more room!
 
Sep 4, 2023 at 9:03 PM Post #12,057 of 12,346
Always better to have more room!
I got away from using 12AU7’s and went with 6SN7’s with adapter. I am now back into 12AU7’s because I run a PrimaLuna integrated amp that takes six.
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Sep 4, 2023 at 9:26 PM Post #12,058 of 12,346
I got away from using 12AU7’s and went with 6SN7’s with adapter. I am now back into 12AU7’s because I run a PrimaLuna integrated amp that takes six.

Tubes take a certain amount of dedication. As a sailor for the past 50 years I liken the difference between tube and solid state to that of a sailboat
vs a powerboat. A powerboat will get you where you are going faster, but sailing to your destination will take you on a different and in many
instances more interesting journey. 😊
 
Sep 4, 2023 at 10:01 PM Post #12,059 of 12,346
I like that! I liken tubes vs SS to lava cake and rice cakes. The rice cake will fill you, but lava cake is lush and delicious.

And don’t get mad, SS lovers, I’m totally 10% kidding.
 
Sep 4, 2023 at 10:09 PM Post #12,060 of 12,346
I like that! I liken tubes vs SS to lava cake and rice cakes. The rice cake will fill you, but lava cake is lush and delicious.

And don’t get mad, SS lovers, I’m totally 10% kidding.
The only solid state I use for two channel is a Bob Carver amp in my shop that has the same specs as one of his tube amps.56C659CF-7CF6-4FCE-8DCE-73D8D1824A3A.jpeg
Oh and maybe a receiver I refurb.
A60FE198-0F45-46D2-BECA-AD6EB0D074BB.jpeg
 

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