bobschwenkler
Well-known member
Hi All,
So I'm looking at a U67 PSU that's got some voltages that are too high. http://www.danalexanderaudio.com/Micpics/Neumann/NU67uPSU.jpg
One thing I'm not sure about is the value of GR3, but as it is I'm getting -15V across it, and the variable resistor R4 is not affecting the voltage drop. I'm getting the same -15V everywhere to the right of R2, all the way to the heater output.
The caps in here are original, but it doesn't seem like out of tolerance caps would be giving me this sort of issue, would it? My main suspect is GR3 at the moment.
I'm also getting between 35V and 40V too much along the B+ supply, all the way between GR1 and the B+ output. The supply is jumpered for 117VAC input and I'm getting very close to that at the input.
Any suggestions?
So I'm looking at a U67 PSU that's got some voltages that are too high. http://www.danalexanderaudio.com/Micpics/Neumann/NU67uPSU.jpg
One thing I'm not sure about is the value of GR3, but as it is I'm getting -15V across it, and the variable resistor R4 is not affecting the voltage drop. I'm getting the same -15V everywhere to the right of R2, all the way to the heater output.
The caps in here are original, but it doesn't seem like out of tolerance caps would be giving me this sort of issue, would it? My main suspect is GR3 at the moment.
I'm also getting between 35V and 40V too much along the B+ supply, all the way between GR1 and the B+ output. The supply is jumpered for 117VAC input and I'm getting very close to that at the input.
Any suggestions?