No sound output, all resistance and voltages correct

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snevok

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Just finished putting together my crack, but I'm not getting any sound output from it.  I'm guessing it's because I wired up the Neutrik 1/4" jack wrong since it's laid out slightly different than the stock, but who knows.  I tried to find a guide on how to wire up the Neutrik, but they were all archived so I had to go off of wording alone ):

Resistances:
1-x
2-x
3-0
4-x
5-x
6-x
7-2.84k
8-x
9-2.85
10-x
12-0
13-x
14-0
20-0
22-0
B3-2.84k
B6-2.84k
RCAR-95.2k
RCAB-94.6k
RCAGND-0

Voltages:
1-78.4
2-177.5
3-0
4-177.5
5-75.8
6-0
7-105
8-0
9-104.1
10-0

Both LEDs on the smaller tube light up. 

I was gonna attach an Imgur album of the build, it won't let me attach links and I have no idea how to just insert a picture, so please 'decode' the following message to see the pictures.  Even though it is painted on the bottom, all metal contacts have the paint stripped off under them.

htt ps://imgur.co m/a/DFqZAnE

Thanks y'all for your time, and hope you're all doing well during these crazy times (:
« Last Edit: April 06, 2020, 10:58:24 AM by snevok »



Offline Paul Birkeland

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Reply #1 on: April 06, 2020, 11:01:21 AM
You used an Alps PC board mount pot without the PC board.  That can cause problems.  Teflon tube sockets can also do strange things.  A4 does not look to be well soldered.  The chassis ground lug by the IEC power entry module is not soldered.
 
I see a lot of random bare wires poking around on your headphone jack.  They all should be trimmed. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline grufti

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Reply #2 on: April 06, 2020, 12:20:38 PM
Looking at your imgur image, the left side green wire plus solder blob on your input tube appears to be in contact with two pins. It's been ages since I worked on a Crack and I have no clue whether it is supposed to do that or not. It's probably worth checking. That and Paul's comments of course.

Your Alps pot looks fine to me.


« Last Edit: April 06, 2020, 12:22:35 PM by grufti »



Deke609

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Reply #3 on: April 06, 2020, 06:55:21 PM
I may be wrong about this, so hopefully PB or someone else can verify, but it looks to me like you've shorted both left and right signal to ground (and to each other) at the Neutrik jack.  Assuming the red and white signal wires are attached to the correct terminals on the Neutrik jack (I don't know if this is the case -- I didn't look up the Neurik jack datasheet), I believe (1) the black wire coming from the center terminal of the 5-terminal board near the 9 pin socket should only attach to the Neutrik terminal to which the other black wire is attached (the one on the left hand side of the pic you posted), and (2) the bare wire connecting the Neutrik terminals to which the red and white wires are attached should be removed -- i.e., there should be no connection between the right signal wire and the left signal wire.

But, again, I may be wrong so wait for confirmation from someone more knowledgeable before making the changes suggested above.

cheers, Derek
« Last Edit: April 06, 2020, 07:03:40 PM by Deke609 »



Offline Paul Birkeland

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Reply #4 on: April 07, 2020, 05:14:20 AM
Yeah, that might be what's in my red circles.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Deke609

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Reply #5 on: April 07, 2020, 07:31:40 AM
Missed that. Didn't see that you had circled the same things.

To the OP - here's how I think the Neutrik Jack should be wired - see attached. (I have a lot of boring work to do, and was looking for an excuse to procrastinate)

cheers, Derek