New Builder learned so much from his mistakes he now wants to rebuild

Agweeks · 2965

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Offline Agweeks

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What DC voltage do you get between terminals 12 and 3?

175

Adam Weeks

Well Tempered Turntable, Sumiko Blue Point 2, Schitt Mani, Stereomour II, Klipsch La Scalas

Schiit BiFrost, Bottlehead Crack/Speedball, Sennheiser HD 6xx


Offline Paul Birkeland

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OK, 12 and 3 are supposed to be wired together in the amp.  Your 12 and 3 are not wired together. 

The common problem I find when I see this condition is that there's a loose black wire on the headphone jack.

There is 100% a broken, missing, or unsoldered black wire in your amp. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Agweeks

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Ok.  I found that if I measure between 12 and the ground lug on the volume pot that the LED's on the 12AU7 illuminate.  Thoughts?

Adam Weeks

Well Tempered Turntable, Sumiko Blue Point 2, Schitt Mani, Stereomour II, Klipsch La Scalas

Schiit BiFrost, Bottlehead Crack/Speedball, Sennheiser HD 6xx


Offline Paul Birkeland

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You have a loose, broken, or disconnected ground wire in your amplifier. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Agweeks

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Does the fact that I can illuminate the LED’s by grounding the volume pot isolate the problem to the volume pod or does it also make it possible the grounding issue is somewhere else?

Adam Weeks

Well Tempered Turntable, Sumiko Blue Point 2, Schitt Mani, Stereomour II, Klipsch La Scalas

Schiit BiFrost, Bottlehead Crack/Speedball, Sennheiser HD 6xx


Offline Paul Birkeland

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You have a loose, broken, or disconnected ground wire in your amplifier.  There are ground wires on the volume pot as well (the black ones).

You have 170V DC between terminal 12 and terminal 3.  These are supposed to be connected by wires.  Yours are not.  This is the problem with your amplifier.  You need to fix this problem with your amplifier before bringing in other information. 

There is a wire from 12 to the headphone jack.
There is a wire from the headphone jack to 3.

One of these is not doing its job.  Please focus on fixing this and leave everything else for later.


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Agweeks

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It was the wire from the volume pot to terminal 3.  I wired that and the amp works.  The voltage for A3 is now 1.5.  Do I need to check anything else?

Adam Weeks

Well Tempered Turntable, Sumiko Blue Point 2, Schitt Mani, Stereomour II, Klipsch La Scalas

Schiit BiFrost, Bottlehead Crack/Speedball, Sennheiser HD 6xx


Offline Paul Birkeland

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If the DC voltage from 3 to 12 was 175V, then you have another one that's loose.  A loose wire from terminal 3 to the volume pot would not create that symptom.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man