Lee Noble

I use the line in at the back of the unit. If you push play on Tape A (with no tape present) then the incoming audio is mixed with the tape output (hiss). Adjusting the level of the input device can moderate the level of audible hiss. This is not for audiophiles, just something I discovered accidentally.

I used an elastic band pulled taught over the blade of a flat headed screwdriver to hold the nut (beneath the yellow screw) in place. Alternatively I was thinking of carving the eraser on the end of a pencil into a wedge shape to do the same job when tightening the screw on reassembly. Just needs something to grip it in place to stop it spinning.