However, from the factory preset #8, i.e. Blackhole, when I activate HotSwitch, Feedback Freeze builds up and up, like self-oscillation.
That’s exactly how that factory preset works. The HotSwitch switches the FEEDBACK parameter to FREEZE, which freezes the feedback and builds up…If you don’t like it, you may edit the HotSwitch mapping by click and hold the HOTSWITCH button in H9 Control, and change parameters to a new setting, then click the HOTSWITCH button again to confirm your change.
aa true yeah, thats why Freeze on Decay parameters do not self build up and oscillate.
Thanks for the clarification.