Strange resistance readings and Popping when inserting headphones [resolved]

Souter · 1525

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Offline Souter

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Hi,

Could anybody offer some advice please, I'm just a novice builder!

I'm in the UK and these are my readings after finishing my build:

RESISTANCE:
1 - 2.48
2 - 2.42
3 - 0
4 - 2.56
5 - 2.45
6 - 0
7 - 1.11
8 - 0
9 - 1.11
10 - 0
12 - 0
13 - 2.50
14 - 0
20 - 0
22 - 0
B3 - 1.11
B6 - 1.11
Center pin - 2.23
Ground tab - 0

VOLTAGE:
1 - 84
2 - 192.5
3 - 0
4 - 192.3
5 - 83.6
6 - 0
7 - 114.2
8 - 0
9 - 114.9
10 - 0

Both led's have lit up.
When I insert headphones the 6080 tube flashes and I get a shock from the metal.

Is there anything obvious that I have done wrong? My soldering looks okay but I'm no expert!
I've attached some pics.

Any help would be very much appreciated.

« Last Edit: March 24, 2022, 01:35:32 PM by Paul Birkeland »



Offline Paul Birkeland

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One of the black wires connected to the headphone jack has no solder on it.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Souter

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Thanks I'll check that.
One of the capacitors I had supplied has a large dent in it, not sure if this could be the reason for my issues?



Offline Paul Birkeland

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One of the capacitors I had supplied has a large dent in it, not sure if this could be the reason for my issues?
You can certainly replace that down the road if you'd like, but I would definitely solder the loose wire first.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline reglys

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Hi Souter

I am waiting for my Crack so I am very interested when people have problems to understand what can go wrong with the kit. Please tell us when it will be resolved.

Do not give up, you are very close.

Hi Mr. Birkeland

Reference picture 232212.
The grounding point at the headphone is crucial if I undertand well:
The black wire coming from the right is the main ground.
All the connections at the top of the picture ( resistor, resistor, bare conductor) should be all soldered together including the main ground and the black wire going to the bottom to bring the ground to the big cathode resistors. What is the purpose of those resistors. Loads for the output tubes when there is no headphone connected?

Test point 2 and 4 are at 192V. Its looks very high according to your spec. Does Souter should change the primary taps on the power transfo?
« Last Edit: March 24, 2022, 12:36:52 PM by reglys »



Offline Paul Birkeland

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What is the purpose of those resistors. Loads for the output tubes when there is no headphone connected?
If you plug a 1/4" to 1/8" adapter into the amp but have no headphones plugged into the adapter, DC voltage will be present on the headphone jack without those resistors.

Test point 2 and 4 are at 192V. Its looks very high according to your spec. Does Souter should change the primary taps on the power transfo?
High but not too high.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Souter

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Hi all,

Thanks so much for your advice, does the headphone jack look okay now?

I'm a bit worried about turning it on again!



Offline Souter

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Its working, and I'm still alive! Happy days.

Thanks all for you advice, now to start the speedball...



Offline reglys

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Hi Sauter

I am glad for you. Maybe you should enjoy your Crack for 2 weeks and after that, you could start your speedball kit.

I know, the DIY audio is very addictive.

I am happy! because of you I know how this female audio jack works and how is important the ground at this nevralgic point.