I have 2 tad 2050 modules and 2 2030 modules. I made 2 pairs of amplified speaker using the 2050's. Only common connection is a "Y" on the input side to accept the stereo source. works perfectly as expected. for the 2030's there are issues. there are 3 paired connection points clearly marked for polarity, 12 volt DC in, AUDIO IN, AUDIO out. when I common the input and output using stereo 1/8 jacks, there is a loud "buzz" in both headphone pieces, and the sound is mixed mono. Not what I want or expected. Should I wire them separately and use a "Y" on in and out? The connections are screw terminals at all points. Solutions?