Hi there, I’m looking for a 4K mini displayport to HDMI adapter to use with a late-2012 iMac. Should I buy the 1.2 to HDMI adapter or the 1.4? Will either work with a 2012 iMac? I’ve tried another brand adapter which was a 1.4 and it sent video ok but wouldn’t pick up the TV in audio outputs. I have an old cheap adapter that works fine, but I don’t know if it’s a 1.2 or a 1.4 adapter. Thanks.