Crack Crackling

magicalmysterytour · 1169

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Offline magicalmysterytour

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on: January 02, 2021, 03:37:31 PM
Hey guys,

I have a moderate crackle in the right channel with my Crack kit (no speedball). I built the kit a few months ago and it made sound but later developed a crackle. Thinking that it was a bad tube, I waited for a new tube (which didn't fix the problem). When I flipped the top plate over to look at the circuit I saw the plate resistor on the right channel is charred and the B+ wire coming from the 6080 is slightly charred. Could this issue be more then a bad joint? Any ideas?

Matthew



Offline Paul Birkeland

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Reply #1 on: January 02, 2021, 03:52:24 PM
From what I can see in your photos:

5L is unsoldered.

4U/4L have not been heated enough for the solder to flow out.

3U has not been heated enough for the solder to flow out.

3L looks unsoldered.

2L is a cold solder joint (needs more heat)

The green wire attached to B7 in the lower hole does not look to be soldered.

The joints at B8 look cold, but I can't see them all the way.

B2 needs more heat to flow out.

The wire at 9U needs more heat/solder.



I would need more photos to get an idea of what happened to the 22.1K resistor.  Does it still measure at 22.1K?  This resistor won't char unless you also have a voltage problem in the amp, and knowing what voltages are off could sure be helpful. 
« Last Edit: January 02, 2021, 03:54:46 PM by Paul Birkeland »

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man