Yes, same as yours Richard.

As a side note I looked at substituting the 16F1705 with a 16F1614 but it only has out1, again on RA0 so did not proceed.

But out2 for me (1705) continues to have the DAC variation superimposed on a 700mV offset no matter what gain I have (x1,2 or 4). The comlementary/inverted output appears to be an undocumented "feature", may have its uses down the track, although I don't understand why the difference in gain between the two.

I tried an external Vref of 1.2V (LM385) and the waveforms appear stunted - may be due I didn't buffer the ref output - however the offset remains and this is the key problem.

Only when I used Vdd as Vref did the offset disappear but in the intended application I need the 1.024V reference, so Vdd is useless. I can use an external DAC (and get some greater resolution at the same time) but it defeats the purpose of using an all-in-one PIC in the first place, plus the pcb is already done albeit a prototype for my needs so I can hack it to use out1.

I won't waste anyone else's time pursuing this further, it is what it is - warts and all...

Cheers, stay safe,
Bill