Moving closer is very risky and chances are quite good that he will spot you long before you spot him. When you have moved as close as the terrain will allow, plan to stay put for at least an hour. You have now done the hard work, and this gobbler is very killable. Let him have your entire repertoire of calls, from soft to loud, from box call to wingbone. Each tom seems to be competing with his nearest neighbor to see who can utter the most double and triple gobbles.
Hens are around as well, and they are yelping, clucking, and purring enthusiastically.
You are sitting in the midst of this hullabaloo. Join right in with the rest of the gang. Call loud, often, and just as enthusiastically. If a hen is near you, utter the same call that she is emitting only call louder and more often than she is. If you can lure her to your position, your chances for success will soar and you may kill a gobbler soon afterwards.