Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: RSpies on February 18, 2017, 05:23:24 AM
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Hi,
Just started the Speedball upgrade to my Crack and I am not getting the correct voltages when I add the first small board. The Crack was working well before I started so I suspect the problem is with the board or the attachments.
Voltage check showed:
OA 78
IA 147
B-A/B 0
IB 147
OB 136
The LEDs on the left (looking from the volume pot end) glow, but much weaker than the two on the right.
Where should I be looking for the problem?
Thanks
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There are quite a few connections on the board that haven't flowed properly. Should all have a neat little "mountain" with an inverse meniscus. i.e. not a blob. They just need a bit of heat from a properly tinned iron and then just a small amount of solder to reflow them. Can't say which one will cure your problem, maybe none of them, but they need doing. Do the same at the tag strip.
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I would agree, more heat, especially on the center legs of those MJE-350's.
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Thanks, I resoldered some of the connections and it works now. The second and fourth points are now in around 160-161 instead of 170-190. I assume that is close enough not to be concerned. I don't notice any problems listening to it.
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Sure, those aren't particularly disturbing. The important voltages are at T1, T5, T7, and T9, with the rest of the high voltage terminals (2, 4, B2, B5, etc) all dropping a bit more than usual as you install each piece of the Speedball.
-PB