B-Stock refers to items that were opened and returned, have a cosmetic blemish or imperfection (powder coat, printing, stripped screw hole, etc), or were used as demo units on pedal boards.  These products are tested and are guaranteed to function normally.  B-Stock items come with our standard lifetime warranty.  ALL SALES ARE FINAL; NO RETURNS, REFUNDS OR EXCHANGES.

ZEQD-Pre™
The All-Analog Simulation Solution

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.

The Technical Side

Unlike the common 12AX7 triode (two elements plus cathode), the EF86 pentode has four internal elements plus cathode. This structure yields measurably superior performance:

• Gain Factor of 185: Significantly higher than comparable triodes
• 44V RMS Output: Substantial voltage swing for enhanced dynamics
• Extended Frequency Response: Full-spectrum clarity from deep lows to detailed highs

What This Means for You

These specifications translate directly to playing experience:

• Touch Sensitivity: The EF86 responds to every dynamic nuance in your playing. Play lighter and it cleans up; dig in and it blooms. Natural expression that follows your hands.
• Full-Frequency Clarity: Extended response means harmonic richness without sacrificing definition. Bass notes stay tight, highs remain bell-like and clear.
• Responsive EQ: Higher voltage and broader bandwidth let the passive Three-Band EQ shape your tone effectively with minimal signal loss. The interactive controls behave like classic tube amp tone stacks—predictable and musical across their entire sweep.

The EF86 brings hi-fi performance to tube preamplification while staying responsive and musical.

Boost: Use the Boost rotary knob for volume control when the Boost is active and the tone controls are bypassed. Boost mode is very loud! Be careful when setting the Boost level, especially when using headphones or XLR out.

Boost Footswitch: This footswitch defeats the tone controls and delivers a full-range boost without altering the frequency response. This switch is only active when the Activate footswitch is on.

Headphone Output: A TRS (Stereo) ¼” headphone jack is located on the left side. Use the Level control to adjust headphone level when the pedal is active. The headphone output works 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 on the left side of the pedal for ground lift on the XLR output.

Cab Sim Bypass Switch: Press this switch on the left side of the pedal to remove the analog cabinet simulation on the XLR output.

Level: Use the Level rotary knob to adjust the output volume when the tone controls are active.

Bass: Use the Bass rotary knob to adjust the frequency range from 20 Hz to 400 Hz.

Middle: Use the Middle rotary knob to adjust the frequency range from 400 Hz to 2 kHz.

Treble: Use the Treble rotary knob to adjust the frequency range from 2 kHz to 20 kHz.

Activate Footswitch: Use this footswitch to activate or bypass the ZEQD-Pre.