We stopped making the switch pickups ("Active EQ") in the mid-'90s. We replaced them with the Pro-Active series. The little rocker switches on the Active EQ pickups change the sound. Switch #1 shifts the coil resonance. On a Jazz Bass neck pickup and a P Bass pickup, the resonance moves downward from 22 KHz to 6.4 KHz. On a Jazz Bass bridge pickup, it moves downwards from 17 KHz to 4.9 KHz. The effect is to give a more focused sound with a harder attack. Switch #2 gives a broad band bass boost of 4 dB for the Jazz Bass neck and P Bass pickups, and 5 dB for the Jazz Bass bridge. The switches can be a very effective tool for changing the tonal "character" of your instrument.