A collaboration between EarthQuaker Devices and Dr. Z Amplification This all-analog tube preamplifier brings together EarthQuaker Devices’ innovative pedal design and Dr. Z Amplification’s decades of tube amp expertise. With a passive three-band EQ, professional headphone output, balanced XLR output, and onboard analog cabinet simulation, the ZEQD-Pre delivers authentic tube warmth and dynamic response in a complete analog amplifier system that fits right on your pedalboard.