Hey.
We especially designed the Heatmaster so it can handle the DDC pumps without any problems. With this in mind the Heatmaster has, as stated above, an extrem high PWM frequency (over 20kHz which is a lot compared to other PWM controls) that is suitable to run all current DDC pumps and Fans without any of the disadvantages PWM normaly brings with it.

Hope this clarifies the matter a bit.

Greetz
Dietz