Tech 21 Sansamp RPM bass preamp. This is a very versatile preamp with endless tone shaping capabilities. With the three band eq with sweepable midrange and drive control you can get everything from a Ampeg type SVT tube growl to a sweet B-15N thump as well as a clean uncolored sound. This is a quality USA made analog circuitry unit. No fancy digital modeling sounds here. It can be used directly with a power amp as designed or incorporated into the effects loop of any stand alone bass head to add additional tonal options. Price now only $180 shipped in lower 48 states. PayPal only.