I dont see a problem with a digital limiter - not uncommon. Note the "level" control is digital as well - only the "sensitivity" control is analog.
Well it's as good as a compression plugin being used in post for limiting, but isn't it utterly useless in the field for protecting against clipping? If I use the limiter in a MixPre/FP24, I can actually prevent clipping, if I use the limiter in an R44, the only thing that can truly prevent clipping is the sensitivity knob isn't it? Sure you can limit after getting the sens knob right, but I can do that in my NLE after-the-fact with way more control, so why would anyone ever bother using it?
I strongly suspect the block diagram is drawn incorrectly. In the manual, they say:
"This switch turns the input level limiter on/off in the
analog circuitry. The limiter compresses the input level appropriately to prevent distortion when the input level is too high. The limiter can be set to operate each channel independently or to be used in combination with channels
(linked). For details, refer to “Limiter link” (p. 68)."
and
"Limiter Turn this ON if you want to prevent unexpectedly loud sounds or strong attacks from producing clipped noise. The limiter threshold is -10 dB relative to digital full scale. The limiter can group and link each channel. See Limiter link (p. 68)."
and
"Limiter Turn this OFF when recording an audio source whose levels have already been adjusted (in contrast to a live audio source whose levels might change unpredictably), or if you have already checked the maximum volume levels that are going to occur. Turn this ON if you need to prevent clipping (distortion) caused by unexpected loud volumes or strong attacks."
and
"The Limiter, Low Cut and Input level knob[SENS] settings are invalid for digital input"...
So according to that it's Pre A/D...and it makes more sense the block diagram is wrong than the limiter is post A/D. Same goes for the low-pass filter.
digifish