The AT-04 archtop pickup separates the piezo sensing unit from the bridge itself. No longer embedded within the bridge's upper saddle, the piezo sensor is attached directly to the underside of the saddle, fully enclosed and shielded to guard against the possibility of line noise.
Repositioning the sensor in this way has made the bridge physically stronger by maintaining its integrity. No slots have had to be cut into the bridge to fit the sensor inside it. In addition, and as a direct result, vibration transmission within the saddle itself and sound transmission to the sensor are both vastly improved.
This pickup has been designed to operate properly and sound terrific without the use of a preamp when plugged into any 'normal' amp (guitar amp, bass amp, etc.). If you require the added ability to be able to plug directly into a P.A. or mixer then you may wish to add one of the Mini-Pre belt-clip preamps to your pickup system.