I whipped up a few of these, using the layout that gaussmarkov had generously provided, and neither of them worked properly, producing an annoying pronounced flutter+tick when the frequency booster section was activated. After much trial and error, I realized that in gaussmarkov's layout and drawing, the 10uf electro on the ground leg of the input stage (labelled as C3) is shown as going to ground. It should go to Vref to work properly.
I'm having a difficult time finding that layout at the moment, but if you have it or the accompanying drawing, and tried building it, unsuccessfully, this is your solution. My apologies for neglecting the error so long. The fault is all mine, not having corrected the original drawing that gaussmarkov used as his reference.