Hello Again, For those who aren't familiar with my project this is a PWM LASER Comms system, specifically a transmitter circuit I am currently developing. I'm having issues getting rid of a DC offset on one of my circuit lines. As can be seen from the waveform diagram below, my 'pink' or oscillator output is offset by approx 200mV. I've tried a range of different capacitors between oscillator output and comparator input to try and block the DC but with no luck. Having the oscillator and 'blue' audio signal both with zero DC biasing is vital for my PWM comparison to be accurate ('green' output). Any feedback appreciated. Thanks.