CRACK OTL - Issues After First POWER ON [resolved]

mipheres · 6025

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Offline Paul Birkeland

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Reply #30 on: November 03, 2016, 06:12:18 AM
Based on your voltages, at least half of the 12AU7 is glowing.  It can't be that both halves don't glow.  Please recheck with the light off in the room.

Also, can you measure (carefully) the DC voltage at A7?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mipheres

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Reply #31 on: November 10, 2016, 03:56:05 AM
Hi,

DC Voltage on A7 is 0 - zero.


Offline Paul Birkeland

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Reply #32 on: November 10, 2016, 04:30:51 AM
Quote from: Caucasian Blackplate on November 03, 2016, 06:12:18 AM
Based on your voltages, at least half of the 12AU7 is glowing.  It can't be that both halves don't glow.  Please recheck with the lights off in the room.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mipheres

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Reply #33 on: November 14, 2016, 08:17:19 AM
yes, looks like both halves glow.
see attached


Offline Paul Birkeland

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Reply #34 on: November 18, 2016, 06:39:19 AM
Carefully check the voltage at A8.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mipheres

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Reply #35 on: November 19, 2016, 08:19:25 PM
A8 measures 11.3V


Offline mipheres

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Reply #36 on: November 25, 2016, 10:35:39 PM
Bump


Offline Paul Birkeland

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Reply #37 on: November 26, 2016, 11:00:56 AM
You can replace the LED or wire in a jumper from A3 to A8.  (The LED has likely taken too much heat and has fractured)

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mipheres

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Reply #38 on: November 26, 2016, 09:04:20 PM
sorry I dont know what to do exactly. can you write a more detailed explanation?
Thanks



Offline Paul Birkeland

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Reply #39 on: December 01, 2016, 01:14:34 PM
Quote from: mipheres on November 26, 2016, 09:04:20 PM
sorry I dont know what to do exactly. can you write a more detailed explanation?
Thanks
Connect A3 and A8 with a piece of wire.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mipheres

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Reply #40 on: December 04, 2016, 08:04:00 PM
Hi,

Looks much better now.
all measurements are around the documentation values:
where it says 90V in the document I measured 82V
where it says 170V in the document I measured 162V

Also at the TRS Peak test, I measured 10V and the decline was to 0V.

Do you think I can connect the HD650?

Best regards,
YM


Offline Paul Birkeland

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Reply #41 on: December 08, 2016, 10:52:34 AM
Yes, I think you're ready to go.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

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