No sound after Speedball installation [resolved]

vinnie · 1559

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Offline vinnie

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on: April 16, 2023, 02:11:53 AM
I finished building my crack a few weeks ago and so far I'm pretty happy with it.
Today I installed the Speedball upgrade.

Unfortunately I don't get any sound now. All LED's light up and the tubes are also heating up.
There is a distinct crack/pop a few seconds after turning the amp on. But no loud buzzing or humming and it is silent otherwise.

My voltage readings:

OA      114,7V
OB      110,2V
G        0V
B+      190V

OA      74,7V
IA       190V
B-A/B  0V
IB       190V
OB      84V

The mains voltage is 230V.


Any help is appreciated.
« Last Edit: April 16, 2023, 10:03:30 AM by vinnie »



Offline Paul Birkeland

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Reply #1 on: April 16, 2023, 05:23:04 AM
Can you post some photos of your build?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline vinnie

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Reply #2 on: April 16, 2023, 06:15:27 AM
If you need any particular angle please let me know



Offline Paul Birkeland

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Reply #3 on: April 16, 2023, 06:37:39 AM
Could I see some shots of the headphone jack and volume pot specifically?

The issue you're hunting down is very likely to be something that was present in the initial build and was knocked loose when installing the Speedball.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline vinnie

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Reply #4 on: April 16, 2023, 10:02:21 AM
No need. I found the issue.  :D

I checked all solder connection before and they seemed fine.

I removed the screws to the large circuit board to get a better view and maybe find some loose wires.
Only then I noticed that the wire connecting 9U to OA was broken somehow.

I rewired it and it did the trick.

Thanks :)