Piezo systems

Double Pick-up for guitar

PU-1 single piezo for acoustic guitars

Blender only
Both signals of a piezo element (PU-4 or the one you're using already) can be mixed with the BS-2 type pre-amp: it has a piezo input and a mic input with adjustable volume for both piezo and mic, a balance control between the piezo and mic,

Piezo Pick-ups for double bass