I spent a couple of days trying connect to the DAC with SSMS to my SQL sandbox server. I read this post, everything tagged 'dac. I even found some posts missing the tag and added it.
My frustration was high, I found several posts like the answer by Milica Medic saying how simple it was.
And I had the answer by Thomas Stringer telling me you can not connect to the DAC with the object explorer.
BUT it turns out the object explorer can connect to the DAC. It grabbed the one and only connection as me, as I was attempting to problem solve, but as I was also logging on as me, I did not realize I had an extra connection via the DAC. Even though I did not have an open Database Engine Query, or object explorer connection. yet it was still there.
I closed and reopened SSMS, to clear any lingering DAC connections that I had accidently made while learning, and magically on re-starting SSMS, I can connect as simple as Milica Medic says!