JFET in MXR Noise Gate Schematic

[LP Hovercraft]

At the risk of sounding like a dumbass, I am sketchy on the orientation of the JFET on the Tonepad layout.  Since its backwards, does that mean (top to bottom) Drain, Gate, Source or Source, Gate, Drain.  I have it built, and have verified my connections are correct, but all I am getting is a quieter (in volume) guitar signal and a faint distortion sound.  I have tried reversing the connects on the 500K pot, too.  I'm a tad stumped.  Have any of you come across this problem?