so.. I tried the npc

The thought of npc seemed like a great idea to me. So I did the quick diode mod ppb my 959. I took it out immediately after seeing what it produced on the scope. What I noticed was a large carrier that I could only get so low with high peaks and very fast transition. The carrier was almost flat on the negative side. This is like distortion on top off distortion correct?
What it needs its a smoother transition on the neg side. Could the resistor value be raised and 2 diodes in series for...

so.. I tried the npc