Final voltage failure

ArtnShit · 4733

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Offline ArtnShit

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on: October 31, 2022, 12:25:28 PM
 Hi,

All the resistances were good. Voltages were fine for everything except the O-connections okc and okd had voltages of 2.24 vdc and 2.3 vdc. The rest had very low or something that couldn’t be picked up on my meter.

Any ideas?

Thanks in advance

a&s


Offline Paul Birkeland

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Reply #1 on: October 31, 2022, 02:16:12 PM
Voltages were fine [...]. The rest had very low or something that couldn’t be picked up on my meter.
Which voltages were fine? Which were too low to be picked up on a meter?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline ArtnShit

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Reply #2 on: October 31, 2022, 03:57:33 PM
 oa ob oc od had very close to zero or unreadable levels. Sorry for the convoluted sentence!

a&s


Offline Paul Birkeland

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Reply #3 on: October 31, 2022, 04:46:38 PM
oa ob oc od had very close to zero or unreadable levels. Sorry for the convoluted sentence!
You can't have OKC and OKD with more voltage over those other values.  Are you sure the meter is set to DC and otherwise working OK?  What do you see at IA and IB?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline ArtnShit

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Reply #4 on: November 01, 2022, 02:45:49 AM
It looks like my meter red lead became a bit loose. I was able to get more detailed readings.

IA 216.5
IB 216.5
OA .1
OB 165.9
OC 58.5
OD 93.6
OKA 55
OKB 94.8
OKC 2.435
OKD 1.565

a&s


Offline Paul Birkeland

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Reply #5 on: November 01, 2022, 04:09:27 AM
Well one side is working perfectly.  I suspect on the non working side that there's either an issue with a solder bridge or cold/missing solder on the bottom of the board, or a miswire on the sockets. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline ArtnShit

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Reply #6 on: November 01, 2022, 09:05:23 AM
Hi Paul,

I have resoldered a bunch of the bridges, tabs, etc., and checked the wiring and am not finding any errors. Am I missing anything?

Thanks in advance

a&s


Offline Paul Birkeland

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Reply #7 on: November 01, 2022, 09:08:37 AM
You either aren't using a soldering iron that's hot enough or you aren't holding it on your joints long enough to flow out, possibly both.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline ArtnShit

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Reply #8 on: November 01, 2022, 09:47:39 AM
I got it working! Thanks for your insight. It ended up being a resistor that needed reflow on the board. Additionally, my last post about the tab in the other voltage test is reading totally fine now with the hold circuit wired up.

I am about to add two Sowter 1990s to the amp. Will that change where I should ground the turntable or anything? So excited to finally hear the phono half of my setup. Once this is done all of the amplification in my system will be Bottlehead.

a&s


Offline Paul Birkeland

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Reply #9 on: November 01, 2022, 10:19:40 AM
The 1990s don't change turntable earthing. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline olegreg

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Reply #10 on: November 27, 2022, 06:39:20 AM
Hi ArtnShit
I am also getting 0 VDC at OA and similar voltages down the A side. Which resistor had the cold joint?