shot
Well-known member
Hi,
I'm in the end of the racking job on some Beag preamp modules. I'm done with PSU, recapping and metalwork, and unit sounds fine. But as a last thing I'd like to balance it's outputs doing impedance balancing.
What would be the right way to do this? I'm confused since I've read some different articles on it and got an advice that confuses me even more.
I got advice from a local guy to just stick 100R in between ground and cold on xlr and be done with it. That seems to me not to be the right way, since I don't know actual output impedance of the unit and 100R is a blind guess...
I got an (real wild diy!) idea to throw a 5K potentiometer in the same spot and run my output wire deliberately near the power xfmr so it picks up some hum, and then monitor the input on my analyzer until I tweak the pot to the point of the max cmrr. Later I replace the pot with a measured value. Would that work?
Or should I replicate C32/R55 network (or more?) on the cold side grounding it? See the attached schemo...
(notice there's three outputs, I'm using only the first one)
best,
Luka
I'm in the end of the racking job on some Beag preamp modules. I'm done with PSU, recapping and metalwork, and unit sounds fine. But as a last thing I'd like to balance it's outputs doing impedance balancing.
What would be the right way to do this? I'm confused since I've read some different articles on it and got an advice that confuses me even more.
I got advice from a local guy to just stick 100R in between ground and cold on xlr and be done with it. That seems to me not to be the right way, since I don't know actual output impedance of the unit and 100R is a blind guess...
I got an (real wild diy!) idea to throw a 5K potentiometer in the same spot and run my output wire deliberately near the power xfmr so it picks up some hum, and then monitor the input on my analyzer until I tweak the pot to the point of the max cmrr. Later I replace the pot with a measured value. Would that work?
Or should I replicate C32/R55 network (or more?) on the cold side grounding it? See the attached schemo...
(notice there's three outputs, I'm using only the first one)
best,
Luka