Been lots of contriversy on what is going on with the knobbs , Turn the machine on and put the gain to 10=+ for getting good depth leave it thear .. put the machine in AUTO AND SET THE THRESHOLD TO A SLIGHT HUMM AND BEFOR YOU GROUND BALANCE I SET THE DISC KNOBB TO 9:00 now after ground balancing i switch it into no motion . now once you are in no motion the funktion of the Disc knobb changes into a sensitivity knobb if the machine is humming to much i turn it to the right untill it just barly is buzzing , this is whear the no motion is at its deepest,, After finding a target , you can turn the disc knob to the right and bring the sensitivity down and narrow up the target , I like this as its just easy to do with your thumb then after i findit i put the coal to the ground and turn the knob left untill i just hear a very soft buzz agine ,, If the buzz starts creeping up on you just move the disc knob to the right a little this way i can switch to any mode fast and check as well like today i got a signal in no motion , so i then just switched into disc,and it gave a good beep , it was a 22 slug i could also thumb up the disc knob as well but when putting it back into no mo AM i set the disc whear it was before, and this is working very well for me and i think the guys at tesoro defenetly got it set up perfectly this is a great light weight machine and a real relick machine i find i am liking this thing more,