Thank you, indeed R9 value is critical. A low value induces cross conduction spikes. A high value adds deadtime, preventing cross conduction spikes. Past the optimal value where the cross conduction spikes get eradicated, the distortion increase. Actually the lowest distortion occurs when there remain visible crossover spikes, same spike magnitude as the coil ripple current at idle. EMI will be badly impacted. This is of course on simulation. Don't know if the real world behaves this way.In the philips circuit, R9 330ohm controls deadtime. As default the philips eval module comes set to high efficiency mode (long deadtime). Play around with the value of this resistor and see what changes that brings in simulation THD.
Have you considered an epoxy prototyping board for the comparator/modulator?I have a test power module that takes the differential signals in from the PUT (Prototype Under Test) IE i dont design a full amp board until i i have prototyped the modulator section and tested it.