The Preset was changed a lot to provide fully synchronised signals. The Notes explain the improvements: A waveform with a built-in Wave Cycle Multiplier of 512 runs at 1/512 of the program frequency. This forms a perfectly synchronised modulation.
A 4 Hz 10% duty cycle gate on the Modulation input provides strong signal spikes whilst keeping the tube cooler than most other Presets.
For more details, please check the link: