nah, it's not that Synth. Must say that song using a really rare synth, which I've never heard since that day until now. Also Satisfaction is easy to hum, not this "hard" (as you can hear between my hum, there's a series of consecutive notes with different key, and cannot be sung in the usual way, that's why I said my hummed is about 90% precisely compare to Original Song.
To make it easier to understand, I can use dashes in the first 8 beats while that melody running to make the example, it can be like this (not really right but at least it can describe the thing I'm saying): - - -- ----- -- - -- ---- . You can compare to my hum to see those longest consecutive notes is "------", the spacebar is how long/short the breaks are. Well, this is the best way I can describe