I'm very sorry to say that your question makes little sense. Freebase DMT does not have a pH. Nor does solid ascorbic acid. A watery solution of ascorbic acid does have a pH but it depends on the concentration of the ascorbic acid in the solution among other factors, like temperature, the presence of other ions etc.). Please read up on basic chemistry if you want to understand this better.
You don't need the ascorbic acid with the DMT freebase, because your gastric acid is much stronger than the ascorbic acid and will do the salting anyway. The only reason for adding ascorbic acid that I see is in case you would be ingesting so much freebase DMT that it would actually upset your stomach acidity. You are not very likely to do that I hope.