Hey so while doing the voltage check on my stereomour Im pretty sure I shorted the probe across terminal 31 and 32. There was a spark and a pop. All the voltages until then where good. Now I get 143 VDC on terminal 31. Terminals 34,36,37,39,40 all now read 0. Looks like the 2a3 tubes no longer glow but its hard to tell with how bright it is right now. I really hope the damage isn't too bad and It's fixable. Thanks.
Stereomour II voltage check [resolved]
- Thread starter DustDoggy
- Start date
Is the fuse still intact?
Can you post some pics of your build? I would wait for all the voltage to bleed down out of the kit and then check the DC resistance of your 120 ohm resistors in your power supply.
This information is readily available by searching the PDF of the manual.DustDoggy said:
Yes, you're correct they are 130 not 120.
What DC voltage do you get if you measure between 41 and 45?
What DC voltage do you get if you measure between 41 and 45?
How about the AC voltage between 19 and 20 on the power transformer terminals?
There's a loose connection on that 41-45 terminal strip somewhere that is causing your problems.
No, the 41-45 terminal strip is a voltage doubler that works off the AC winding of the power transformer. You have the correct AC voltage coming out of the power transformer but you don't have the appropriate DC voltage appearing at that terminal strip. Since you have about half of what I would expect, you are inadvertently half-wave rectifying what's coming out of the PT rather than full wave doubling it. Most of the time this happens from a loose connection not allowing everything to conduct properly when it's supposed to.
Beyond that you also have a distribution problem beyond this terminal strip, but you need to address the issue above before looking for other problems.
Beyond that you also have a distribution problem beyond this terminal strip, but you need to address the issue above before looking for other problems.
Just thought I would post an update. After much reflowing, prodding, reflowing and head scratching I wasn't really getting anywhere. I then read a thread where someone had the same problem and decided I would replace the 130ohm 2W resistors. All voltage checks where spot on and the amp is working perfectly and sounds amazing! I'm excited to start the reduction build and get the vinyl spinning.
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thoven0215
Member
Just wondering, was that thread from me? I got my amp working last weekend, and it has been amazing. Big thank you to PB because I would have not been able to do it without his help.
