R40 gets hot, voltages a bit off

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R40 gets hot, voltages a bit off

Postby bencollins2 » Sun Aug 20, 2017 4:07 pm

Hey everyone! So I've built two N72s that sound amazing, and working on my third.

This time, it seems that R40 is getting hot. I'm measuring correct voltages at Q1-Q3, but they're slightly off from Q4-Q6.

I did make a dumb mistake at one point, turning R39 CC clockwise rather than counter-clockwise, and saw a bit of smoke, though I killed the power immediately. Could this have fried anything important?

I've pulled out all the transistors and re-soldered, re-flowed everything in that area. Still getting these slightly off values, and can't touch R40 for more than a couple of seconds. Maybe this is all within a certain tolerance..

Q4
Collector: 5.6
Base: 0.88
Emitter: 0.3

Q5
Collector: 22.2
Base: 5.57
Emitter: 5.0

Q6
Collector: 22.2
Base: 4.97
Emitter: 4.39
bencollins2
 
Posts: 1
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