I've had this JG G36C for about a week now after buying it from Toronto Airsoft and having them replace the spring so that I can play CQB games; 350 fps on a modify m90 spring.
One thing I noticed is that the gearbox sounds different when I'm connecting it directly to the gearbox versus the extra wiring that goes to the hand guard with a fuse in it (came stock).
http://youtu.be/x4Z1jspjTsA
Connected directly to the gearbox, it sounds high pitched, fast, and crisp.
Connected to the fuse wiring, it sounds lower pitched, slower, and i don't know... bad.
Another thing I'm concerned about is that the fuse is actually starting to burn out (refer to attached pic).
Any suggestions?