SamyGO

Not quite possible for C series.

In B series, indeed, recording channel without encryption is supported by TV self!
Original Samsung code produce DRMless stream at B series. We just write a wrapper to samsungs own code so start PVR functions.
In C series, we just enable TV's own PVR tool from Service Menu instead of writing a wrapper. It's same thing to start functions by wrapper... But in C series, TV produces DRM'ed files by itself.

So we do not changed pvr functions on B series. Just used that functions. So this is the main difference...
I wish you understand the situation well now.

So is it impossible to have unDRMed stream at C series? No, but it's not "quite" possible.
That require much work & reverse engineering on C series...

Answers are not here, I am B series owner and donations doesn't enough to buy me a TV, just for hacking
If you will to do that, install IDA and look what you could recover from exeDSP.

What is IDA? An emulator or disassembler? Where do you get it? Another possibility is to remove DRM from file after it's recorded.

IDA is disassembler, try to use google.