Bottlehead Crack Voltage Check

xpboy7 · 1975

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Offline xpboy7

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on: May 07, 2017, 07:39:42 AM
Yo guys, I've just finished building my first DIY headphone amp (with my father who can weld really well).
I've encountered a couple of problems in the voltage check(Page 49) -
I measured 5V instead 50V-100V on terminal 5
I measured 66V instead of 90V-115V on terminal 9
I measured 60KΩ-70KΩ at the Center of the black RCA instead of 90KΩ-115KΩ - not steady at all (jumps between 30KΩ up to 1, wouldn't get lower even when trying to change the measurement to 2M.)

Can someone please attach an image of the first check? I'm not sure I got it right (Page 47).

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( ) Attach the negative lead (typically black) of a volt-ohm meter to the ground buss at terminal
12U. Use of a clip lead to connect the black test lead to the ground buss will free one hand,
making testing much easier and safer. Using the positive lead (typically red) of the volt-ohm
meter, check the resistance of the following terminals. Before you begin, put your red lead on
the ground tab next to the power transformer and see what your meter reads (most likely a
fraction of an ohm); consider any readings you get near this value as being 0Ω.
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Best Regards,
« Last Edit: May 07, 2017, 08:18:48 AM by xpboy7 »



Offline fullheadofnothing

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Reply #1 on: May 07, 2017, 08:28:28 AM
It does appear that you have mismounted at least the red jack—the shoulder of the shoulder washer appears to be on the underside of the chassis pointing up towards the nut. It needs to be above the chassis seated down in the hole to isolate the jack.

The wire that is supposed to go to A1 is going to A2.


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Offline xpboy7

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Reply #2 on: May 07, 2017, 10:24:16 AM
It does appear that you have mismounted at least the red jack—the shoulder of the shoulder washer appears to be on the underside of the chassis pointing up towards the nut. It needs to be above the chassis seated down in the hole to isolate the jack.

The wire that is supposed to go to A1 is going to A2.

Thanks a lot for the reply, I'll check it out and update during the week (most likely weekend-ish) :)