A collaboration between EarthQuaker Devices and Dr. Z Amplification
This all-analog vacuum tube preamplifier combines EarthQuaker Devices' innovative pedal design know-how with Dr. Z Amplification's expertise, backed by decades of experience in the field of tube amplifiers. Featuring a three-band passive EQ, a professional headphone output, a balanced XLR output, and built-in analog cabinet simulation, the ZEQD-Pre delivers authentic tube warmth and dynamics in a complete analog amplification system that integrates perfectly with your pedalboard.
Practice amp with headphones
The headphone output integrates analog cabinet simulation for a realistic amplification experience during your silent practice sessions. Enjoy the full character of EF86 tubes without disturbing your roommates.
Direct amplifier via XLR
Plug the balanced XLR output directly into any console or audio interface and use the ZEQD-Pre as your main amplifier. Analog cabinet simulation is available on demand, or engage the Cab Bypass switch to send a clean signal to your favorite IR loader or modeling software. Ideal for direct recording, backline-free gigs, or hybrid multi-signal path setups.
Flexible routing
All outputs operate simultaneously, even when the pedal is bypassed. Send your signal to an amp, route it directly to the front-of-house console, and listen via headphones—all at the same time. This routing flexibility makes the ZEQD-Pre an indispensable studio tool.
The ZEQD-Pre uses the EF86 pentode, the same tube that gives many Dr. Z amplifiers their crystalline hi-fi sound and exceptional responsiveness.
Technical specifications
Unlike the classic 12AX7 triode (two elements plus a cathode), the EF86 pentode has four internal elements plus a cathode. This structure offers significantly superior performance:
Gain of 185: Significantly higher than that of comparable triodes.
44V RMS Output: High voltage swing for increased dynamics.
Extended frequency response: Clarity across the entire spectrum, from deep lows to detailed highs.
What this means for you
These specifications translate directly into a better playing experience:
Touch sensitivity: The EF86 reacts to every dynamic nuance of your playing. Play lightly and the sound thins out; play harder and the sound blooms. A natural expression that follows your hands.
Clarity across the frequency range: An extended response offers harmonic richness without sacrificing definition. The lows remain precise, the highs crystalline and clear.
Responsive EQ: Higher voltage and wider bandwidth allow the three-band passive EQ to effectively sculpt your sound with minimal signal loss. The interactive controls behave like the tone circuits of classic tube amplifiers: predictable and musical throughout their range.
The EF86 offers hi-fi performance in a tube preamp while maintaining responsiveness and musicality.
Boost: Use the Boost rotary knob to set the volume when Boost is engaged and tone controls are bypassed. Boost mode is very powerful! Be careful when adjusting the Boost level, especially with headphones or the XLR output.
Boost footswitch: This footswitch bypasses the tone controls and offers a full-bandwidth boost without altering the frequency response. It is only active when the engage footswitch is on.
Headphone Output: A 6.35mm (1/4") stereo TRS jack is located on the left side. Use the Level control to adjust the headphone volume when the pedal is engaged. The headphone output operates as a unity-gain amplifier with cabinet simulation, even when the pedal is bypassed.
Direct Output: A balanced XLR output is located on the left side of the pedal.
Ground Lift switch: Press this switch located on the left side of the pedal to ground the XLR output.
Cab Sim Bypass switch: Press this switch located on the left side of the pedal to disable the analog cabinet simulation on the XLR output.
Level: Use the Level potentiometer to adjust the output volume when the tone controls are engaged.
Bass: Use the Bass potentiometer to adjust the frequency range from 20 Hz to 400 Hz.
Mids: Use the Mids potentiometer to adjust the frequency range from 400 Hz to 2 kHz.
Treble: Use the Treble potentiometer to adjust the frequency range from 2 kHz to 20 kHz.
Engage Footswitch: Use this footswitch to engage or bypass the ZEQD-Pre.