Originally posted by jatrax Just FYI, but I do not think you and the OP are talking about the same thing. The 2x macro converters are a special form of tele-converter that include a helicoid allowing 'macro' focusing distances. The OP just said 2x converter, so they might be looking at the old cheap 2x converters which IMHO are not worth the $30. The macro converters are better made and even though the IQ will suffer they still have a use. I have two of them, one with the glass removed to make a variable extension tube.
I know what the OP is talking about, and was assuming the OP and I are on the same page. The 2x Macro converter is a regular MC7 teleconverter that has a macro feature as you said. I was conveying my experience with the teleconverter since he was specifically asking about old Vivitar teleconverters, which this is (just with an extra feature). I got my macro converter attached to a Super Program for about 30$, so YMMV.
So after Ebaying, it does seem as if the OP might not be on the same page as me, BUT you can find MC7 teleconverters for around 30$ without A contacts. If you're going to spend that little money on a TC, that's the one I'd go for.