No, they are both adjusted the same way. You have to loosen the brush holder clamping screw, then slide the adjuster UP (clockwise as viewed from the rear) to lower the output, or DOWN (counter clockwise as viewed from the rear) to increase the output. As mounted on the engine, the adjustable brush faces the outside. Here are a couple pictures showing the 3 and 5 brush holders, but since I always use an electronic voltage regulator, that's the only pictures I have at the moment.
Be very carefull when making adjustments, as the bakelite brush holder is very fragile, and many are cracked or broken with pieces missing.