There is always someone finding a problem with whatever is posted. The original circuit used an established method. It has been in use for about 20 years. Here is a little more complicated circuit that may work better. The only problem I had with the original is the RF gain is the volume control so when you turn it up on a weak signal and then get a boomer on channel it may tend to hurt your ears. The diodes used here limit the peaks and help prevent the ear damage. It can be switched from balanced to unbalanced by installing or removing the jumper. This particular circuit has been used in commercial units since the '60s.