Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Universe Man on August 14, 2021, 06:01:29 PM
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I measured terminal 1 as instructed and got a value of ~125v. Any suggestions? Passes resistance test and both LEDs and tubes turn on.
I’ll add that terminal 2 measures in the acceptable range.
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Can you post some build photos? What are the voltages on terminals 1-10? You can't have both terminal 7 and 9 have acceptable voltages with 125V on terminal 1.
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1 120
2 160
3 0
4 161
5 118
6 0
7 128
8 0
9 126
10 0
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Can you post some build photos? What are the voltages on terminals 1-10? You can't have both terminal 7 and 9 have acceptable voltages with 125V on terminal 1.
I checked over all the joints a couple times and they all seemed okay. Unless there is something I’m just missing repeatedly, which there might likely be, I’m not sure what could be wrong.
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Posting photos may help.
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Posting photos may help.
I put a couple in a reply above
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Posting photos may help.
Do you think more angles are needed?
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If you pull the 6080 and run the amp with just the 12AU7, what voltage do you get at terminal 1?
Also, can you carefully measure the DC voltage at A3?
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If you pull the 6080 and run the amp with just the 12AU7, what voltage do you get at terminal 1?
Also, can you carefully measure the DC voltage at A3?
1 is 152 without the tube
A3 is 2v
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Looking back over this with fresh eyes, your voltages on 1 and 5 are too high. This would have me more suspicious that you have a bad solder joint on the green twisted pair of wires running between the octal socket and the 9 pin socket, and you aren't getting the 12AU7 all the way hot because of that.
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Looking back over this with fresh eyes, your voltages on 1 and 5 are too high. This would have me more suspicious that you have a bad solder joint on the green twisted pair of wires running between the octal socket and the 9 pin socket, and you aren't getting the 12AU7 all the way hot because of that.
I touched up those joints but t1 still goes up then settles around 122
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Is the 12AU7 glowing up top?
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Is the 12AU7 glowing up top?
Yes
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Can you double check that you didn't get a 12AT7 by mistake?
Something just isn't adding up here...
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Can you double check that you didn't get a 12AT7 by mistake?
Something just isn't adding up here...
Box says 12au7, tube text is worn down a bit and harder to interpret. Might look like it says At or something? What do you think?
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Can you see any printing on the tube? I think you may have accidentally gotten a 12AT7.
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Can you see any printing on the tube? I think you may have accidentally gotten a 12AT7.
I can make out a 6679, online it says that’s a 12at7. Problem solved(ish)! I guess the question now is what to do about it…
Regardless of if I’m getting a replacement 12au7, is it safe now to finally use with my hd6xx? I see that it’s higher output, but the headphones are fairly high impedance.
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Can you see any printing on the tube? I think you may have accidentally gotten a 12AT7.
Also, do the voltage readings seem good considering it’s a 12at7?
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You definitely can't use a 12AT7 in the amp. You can contact replacementparts(at)bottlehead(dot)com to let them know you got a 12AT7 by mistake. Including a link to this thread is a nice idea, along with your name and mailing address.
The voltages at terminals 1 and 5 would be about what I would expect for a 12AT7.
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You definitely can't use a 12AT7 in the amp. You can contact replacementparts(at)bottlehead(dot)com to let them know you got a 12AT7 by mistake. Including a link to this thread is a nice idea, along with your name and mailing address.
The voltages at terminals 1 and 5 would be about what I would expect for a 12AT7.
Ok, I will take care of that.
Thank you for helping.