I thought that it was time to start a new thread for the ShibaSoku Distortion Analyzer. I have reverse engineered part of an AD725C and have attached some schematics. I am in work at the moment so time is limited which is my excuse for the messy schematics. I can't guarantee the accuracy.
The equipment is old school and I think that a better way to go is to use a Sound Card preceeded by a Notch Filter as recommended elsewhere.
The equipment is old school and I think that a better way to go is to use a Sound Card preceeded by a Notch Filter as recommended elsewhere.