I've found that double tempo helps. 77 bpm x 2 = 154 bpm. Its a little tricky because of the fast metronome but once you get used to it, it becomes easier.
also 1/32 time correct if you want to keep the regular tempo. 1/32 with double tempo would help get those notes closer to where you want them.
you can try it with TC off too, and put 16 levels on and use two pads, or load the sample into two pads.
See you in PA