Edit 12 aug 2011: posted actual schematic.
Hi everyone!
I'm finishing a build of 4x6SN7 preamps (one bottle, no feedback) in an old Geloso chassis, it will look pretty cool!
ACTUAL SCHEMATIC:
-FACTS:
-I plan on running the outputs unbalaced at first, no output transformer, just the output cap.
-I have no resistor loading the output yet, the output cap is hanging until I connect it to some input.
Now I think I'm not getting this:
-The B+ gets to one side of the output coupling cap (330V approx)
-And the other side measures 170V even though it's not physically connected anywhere.
-QUESTIONS:
-Shouldn't it measure 0V? I mean, it's the point of that blocking cap, right?
-Could it be that as soon a I connect it to ground with my meter (or my finger as it has happened!!!) some current starts coming back from the PSU or from the other preamps?
-Will loading the output with a resistor solve the problem?
I would like to be sure that there is not something really wrong that I will hide in some way (like by dumping current through that loading resistor for instance).
This is the last step in this build, if you guys want to help me not blow it all up, I would really appreciate it!
Best
jules
Hi everyone!
I'm finishing a build of 4x6SN7 preamps (one bottle, no feedback) in an old Geloso chassis, it will look pretty cool!
ACTUAL SCHEMATIC:
-FACTS:
-I plan on running the outputs unbalaced at first, no output transformer, just the output cap.
-I have no resistor loading the output yet, the output cap is hanging until I connect it to some input.
Now I think I'm not getting this:
-The B+ gets to one side of the output coupling cap (330V approx)
-And the other side measures 170V even though it's not physically connected anywhere.
-QUESTIONS:
-Shouldn't it measure 0V? I mean, it's the point of that blocking cap, right?
-Could it be that as soon a I connect it to ground with my meter (or my finger as it has happened!!!) some current starts coming back from the PSU or from the other preamps?
-Will loading the output with a resistor solve the problem?
I would like to be sure that there is not something really wrong that I will hide in some way (like by dumping current through that loading resistor for instance).
This is the last step in this build, if you guys want to help me not blow it all up, I would really appreciate it!
Best
jules