Left channel issue [resolved]

Eldergod · 712

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Offline Eldergod

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on: May 16, 2021, 10:59:43 AM
Hey all! Built a Crack last Fall, and have been enjoying it. Decided to build the SEX as a gift for a buddy who sadly doesn’t currently have any tubes in his system. Finished it up yesterday, but no sound out of the left channel. Headphone jack has both channels present, switched the tubes with the same result, and retook all measurements. Any thoughts on chasing the issue? Only strange thing is my measurement of H4 and H7 are negative 3Vish. Any help from you all is appreciated.
« Last Edit: May 17, 2021, 02:47:48 PM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: May 16, 2021, 11:24:52 AM
If you have left and right channels at the headphone jack but you do not have left and right channels at the speaker jacks, the only possibility is the wiring from the HP jack to the speaker jacks.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Eldergod

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Reply #2 on: May 16, 2021, 11:53:24 AM
Thx. There is continuity on all wiring from headphone jack input and out to speaker terminals. Is that strange?



Offline Eldergod

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Reply #3 on: May 16, 2021, 12:18:20 PM
Update. NOT getting L channel in headphones.  I don’t think I had them seated all the way down. So something farther up the chain.



Offline Paul Birkeland

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Reply #4 on: May 16, 2021, 12:32:23 PM
The H4 and H7 measurements are normal.  Those feed both tubes; a problem there would be a problem on both channels.

Are you 100% sure your DC voltage checks were correct?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Eldergod

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Reply #5 on: May 16, 2021, 12:34:24 PM
Yes, as much as a I can be.  I’ll check again. I can’t seem to get continuity between the L input and the volume pot input which is odd.



Offline Eldergod

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Reply #6 on: May 16, 2021, 12:44:21 PM
Update, volume pot is fine.



Offline Paul Birkeland

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Reply #7 on: May 16, 2021, 01:18:31 PM
Can you post some build photos?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Eldergod

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Reply #8 on: May 17, 2021, 02:47:56 AM
Yes.  If you need closer pics of a section, let me know.  Including all four sides below.



Offline Paul Birkeland

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Reply #9 on: May 17, 2021, 05:05:55 AM
The blue/white twisted pair of wires leaving the volume pot and going to the left channel are not properly installed.
« Last Edit: May 17, 2021, 05:33:21 AM by Paul Birkeland »

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Eldergod

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Reply #10 on: May 17, 2021, 05:17:52 AM
Did you mean Green/White leaving the headphone jack (or Blue/White leaving the volume pot)?



Offline Paul Birkeland

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Reply #11 on: May 17, 2021, 05:33:41 AM
Oops, volume pot.  The coffee is starting to kick in finally.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Eldergod

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Reply #12 on: May 17, 2021, 01:24:52 PM
That was it! All good.... thanks so much Paul! Up and running, and sounding great. Can’t wait to build the next one, lol. Really appreciate your support!