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March 24, 2019, 06:16:55 am

Author Topic: Glow test 2AU7  (Read 114 times)

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Offline jake111

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Glow test 2AU7
« on: March 15, 2019, 03:51:24 pm »
I have the lower front and back of the 2AU7 glowing, the upper part only glows in the front. Is this normal?
Thanks, Jess

Offline Paul Birkeland

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Re: Glow test 2AU7
« Reply #1 on: March 15, 2019, 05:10:30 pm »
That could be totally normal depending on the 12AU7.  Sometimes the placement of the heater inside the cathode sleeve isn't 100% consistent between halves (and it doesn't need to be).

-PB
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline jake111

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Re: Glow test 2AU7
« Reply #2 on: March 17, 2019, 11:01:27 pm »
Finished and sounding great with HD 6XX.
The voltage test terminals that were supposed to be 0v were a bit higher.
3. 00.3v
6. 00.3v
8. 00.5v
10. 00.3v
Is this something to be concerned about?

Jess

Offline Paul Birkeland

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Re: Glow test 2AU7
« Reply #3 on: March 18, 2019, 04:26:51 am »
This is probably not an issue.  If your meter has different ranges, it may not resolve 0V very well on a setting like 200V. 
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline jake111

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Re: Glow test 2AU7
« Reply #4 on: March 18, 2019, 09:26:41 am »
The chassis plate gets pretty darn hot. Is there a temp range for that?

Offline Paul Birkeland

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Re: Glow test 2AU7
« Reply #5 on: March 18, 2019, 10:03:16 am »
The chassis plate gets pretty darn hot. Is there a temp range for that?
If you pass your voltage checks, the chassis plate temperature is appropriate.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man