The HKs don't have a name for it, but "surround off" + "DSP off" + "no tone controls" = pure direct, ie analog inputs go straight through without ever being digitized or otherwise manipulated.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8