Radial StageBug SB-4 Active Piezo Instrument Direct Box

The Radial StageBug SB‐4 Active Piezo Instrument Direct Box solves the age‐old problem of piezo pickups sounding harsh and unnatural through PA systems. This compact active DI has been specifically engineered for piezo transducers, featuring an ultra‐high 5 meg ohm input impedance that smooths out the troublesome peaks and frequency response issues that plague typical piezo installations. Perfect for orchestral artists, bluegrass players, and acoustic performers who need reliable amplification, the SB‐4 fits easily inside your instrument case and works brilliantly with violin, dobro, mandolin, cello, double bass, and other stringed instruments.

The active circuitry balances your signal for long cable runs up to 100 metres without signal loss, while maintaining exceptional linearity and minimal distortion across the entire audio spectrum. Powered by 48V phantom power from your mixing desk, there’s no need for batteries or external power supplies. The unit includes both a standard XLR output for the PA system and a 1/4" auxiliary output for connecting to a stage amplifier, giving you maximum flexibility in your setup.

Two crucial features help combat the feedback issues that acoustic instruments face on stage. The built‐in high‐pass filter eliminates excessive low‐end frequencies that can cause wooden instruments to resonate and feedback, while the 180° polarity reverse switch tackles acoustic hot spots by changing the phase relationship between your PA system and room acoustics. This phase flip can eliminate problematic frequency peaks at specific stage locations without requiring harsh EQ adjustments that compromise your natural tone.