Additional details: The circuit, as shown above, is just one of 3 identical stages in parallel. As shown above the output (pink trace) is measured across R which is actually 2-5 Ohm resistors in series. The problem I see with the output are the over shoots. With a 12V DC supply IN, I'm getting spikes to 25V and down to -9V. The input signal has no over shoots until it is plugged into the circuit. Any help would be appreciated.