thornev
Super Member
Novice question coming...
I've built the Unity Gain mod on a small board and I'm ready to install it in my 500C. I know the left and right input leads attach to the center tabs of the volume control. What I don't know is (1) what to do with the left and right output leads as I'm not taking advantage of (i.e. connecting to) the preamp OUT and power amp IN circuits and (2) how to find a 5 mA connection to which to connect the IN4007 diode.
I've not done much of tracing voltage and current in a live unit except for when I installed the IBAM circuit. Is it a matter of probing around components with a digital multimeter until I find 5mA? Since it's a bias connection I assume that's a matter of following a specific circuit, but where do I start?
And because some people like pictures, see attachment (please excuse the lack of aesthetic symmetry). Black and white leads are left and right OUT. Red and green leads are left and right IN. Grey leads are ground and 5mA connections.
I've built the Unity Gain mod on a small board and I'm ready to install it in my 500C. I know the left and right input leads attach to the center tabs of the volume control. What I don't know is (1) what to do with the left and right output leads as I'm not taking advantage of (i.e. connecting to) the preamp OUT and power amp IN circuits and (2) how to find a 5 mA connection to which to connect the IN4007 diode.
I've not done much of tracing voltage and current in a live unit except for when I installed the IBAM circuit. Is it a matter of probing around components with a digital multimeter until I find 5mA? Since it's a bias connection I assume that's a matter of following a specific circuit, but where do I start?
And because some people like pictures, see attachment (please excuse the lack of aesthetic symmetry). Black and white leads are left and right OUT. Red and green leads are left and right IN. Grey leads are ground and 5mA connections.
Attachments
Last edited: