Schertler Guitar Contact Mic Open Box Demo  From Schertler

One of the most natural sounding acoustic sensors available and a favourite with sound engineers, DYN-G is suitable for use in both solo and orchestral environments with moderately loud sound levels. 

Easily and safely fitted to the body of the instrument, using special adhesive putty, the sensor can be appropriately positioned to capture the guitar’s best tonal qualities. It can also be quickly transferred from one instrument to another (even during performances or recording sessions). A balanced XLR connector enables direct connection into an acoustic guitar amp, or a microphone input of a mixer. 

DYN-G also works effectively through full-range amplification systems such as the Schertler amplifier series.