Crack 1.1 noise in right channel

A Jedi · 9901

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Offline Paul Birkeland

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Reply #45 on: July 01, 2019, 10:16:05 AM
The 22.1K resistor at 5U is not well soldered or connected, though that is a left channel component.

If you wiggle the wire at A5, does it move in that joint?

The image of the octal socket is out of focus, so it's tough to say much about that.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline A Jedi

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Reply #46 on: July 01, 2019, 10:20:31 AM
Both A5 and 5U are rock solid. I have more pics but site errors when I try to post with attachments...I get a 500 error.
« Last Edit: July 01, 2019, 10:22:55 AM by A Jedi »



Offline Paul Birkeland

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Reply #47 on: July 01, 2019, 10:45:31 AM
You may need to shrink the size down a little bit.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline A Jedi

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Reply #48 on: July 01, 2019, 10:56:33 AM
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Offline A Jedi

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Reply #49 on: July 01, 2019, 10:57:12 AM
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Offline A Jedi

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Reply #50 on: July 01, 2019, 10:57:49 AM
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Offline A Jedi

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Reply #51 on: July 01, 2019, 10:58:23 AM
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Offline A Jedi

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Reply #52 on: July 01, 2019, 10:59:01 AM
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Offline A Jedi

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Reply #53 on: July 01, 2019, 10:59:32 AM
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Offline A Jedi

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Reply #54 on: July 01, 2019, 12:52:00 PM
One thing I haven't mentioned is that there was a small chip on the transformer when I received the kit. I took pics and emailed Bottlehead immediately and was told it shouldn't be a problem. Is it possible the transformer was dropped and is damaged? And that's why I'm having these issues?



Offline Paul Birkeland

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Reply #55 on: July 01, 2019, 02:09:41 PM
The transformer is definitely not an issue.  That little piece of the bobbin that snapped off doesn't serve any function.

The joints that pop out at me are 6U and the 3K resistors attachment point at 3U.  I see a lot of flux at 3U and it's possible that one is really well soldered and the other is somewhat insulated by flux.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline A Jedi

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Reply #56 on: July 01, 2019, 05:25:04 PM
The transformer is definitely not an issue.  That little piece of the bobbin that snapped off doesn't serve any function.

The joints that pop out at me are 6U and the 3K resistors attachment point at 3U.  I see a lot of flux at 3U and it's possible that one is really well soldered and the other is somewhat insulated by flux.


Went over those. No difference. I give up. Will send it in.



Offline A Jedi

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Reply #57 on: July 04, 2019, 02:23:07 PM
Ok fine I guess I haven't given up. Spoke to to Doc B on the phone and ended up cleaning both the tube pins and sockets. Also tried a cheater plug to lift ground. Tiny improvements but still not enough.

One thing dawned on me - the PT had some sort of resin on the contacts. I basically just poked holes in it to slide the wires through and then soldered. Is there any benefit to undoing all PT wiring, making sure the contacts are completely clear of the "resin" and re-soldering?



Offline Paul Birkeland

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Reply #58 on: July 04, 2019, 02:33:36 PM
It is varnish, and it should burn right off when you solder.  Also, every connection to the power transformer is common to both channels, so an issue here that made noise would make noise in both channels.  Such an issue should also rather immediately present itself in the voltage checks. 

If you want to check the operation of the transformer, you can measure the AC voltage between pins B7 and B8, then check the AC voltage between pins 18 and 19.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline A Jedi

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Reply #59 on: July 04, 2019, 03:04:28 PM
It is varnish, and it should burn right off when you solder.  Also, every connection to the power transformer is common to both channels, so an issue here that made noise would make noise in both channels.  Such an issue should also rather immediately present itself in the voltage checks. 

If you want to check the operation of the transformer, you can measure the AC voltage between pins B7 and B8, then check the AC voltage between pins 18 and 19.

Hmmm ok then that's not it. And voltage checks are a-ok.