Speedball upgrade help [resolved]

istudysand · 514

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Offline istudysand

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on: October 25, 2020, 07:55:31 AM
I'm new to bottlehead. I recently built the crack. I bought a speedball upgrade for my crack. The crack was working great prior to the speedball upgrade. When I added the small board, it passed the voltage check, however after I added the large board it passed the resistance check, but fails the voltage check.
OA - 17V
OB - 55V
G - 0V
B+ - 109V
I followed the troubleshooting guide until it suggested post on forum. I went back and retested the voltages of 1-10.
1 - 75V
2 - 113V
3 - 0V
4 - 112V
5 - 27V
6 -0V
7 - 4V
8 - 0V
9 - 30V
10 - 0V
Would appreciate any help!
« Last Edit: October 26, 2020, 05:20:19 AM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: October 25, 2020, 08:18:33 AM
Typically I would expect to see this problem when the mounting hardware on the TIP50 transistors isn't installed properly, or if there are soldering issues on the bottom side of the big board.  You might want to pop the wires out of one side and flip it over so we can see if there are any solder bridges shorting things out. 

It's also not ideal to have the 2N2222 transistors touching the board, so if you can heat those joints up and just move each transistor a tiny bit off the board, that's not a bad idea either.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Paul Birkeland

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Reply #2 on: October 25, 2020, 08:19:24 AM
A4 also doesn't look like it's well soldered.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Paul Birkeland

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Reply #3 on: October 25, 2020, 08:21:00 AM
The wire leaving B2 and going to the front of the amp needs to be crimped around the socket pin and resoldered.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Paul Birkeland

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Reply #4 on: October 25, 2020, 08:22:11 AM
The black wire on the volume pot that goes to the center lug of the 9 pin socket also needs to be crimped on the pot lug and resoldered. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline istudysand

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Reply #5 on: October 25, 2020, 05:54:43 PM
Thanks, it works now!