Reverse Sawtooth synthesizer vco- seeking feedback to improve design

[Ryan OMalley]

Hi everyone, I'm working on a reverse sawtooth VCO that is controlled by a linear control voltage. my design is inspired from VCO designs that various analog Yamaha synthesizers used in the 1970's. I went with the linear volts/hz control method so that I wouldn't need to have an exponential converter circuit, and so that I can run control voltage into it right from a DAC circuit  It works fairly well, except that the circuit won't oscillate below 96 hz. I'm not sure if I need to increase the capacitance or add hysteresis to the comparator. I will attach  the schematic diagram and a picture of the output waveform on my oscilloscope. any suggestions on how to improve this circuit would be greatly appreciated.