Theres a trick I learned to AQ amps, when ever you move the nob, its like a "tick," you feel it...
for SSF every tick, it goes up by 1, starting from 5 ending @ 50 i think, so I moved my nob 20 times, so that puts me @ 25 hz..
for LPF, every tick is 5, so I moved it up, counting by 5's till I got to 80.
pics uploading