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
Controls :
- 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 bypasse.
- 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.
TECH SPECS :
- Dimensions : 5.88 x 3.94 x 2.75 in. (149 x 100 x 70 mm) with knobs
- Current Draw : 500 mA
- Input Impedance : 10 MΩ
- Output Impedance : Variable
- Headphone Out Impedance : 39 Ω
- Direct Out Impedance : 100 Ω
- Switching : ZEQD-Pre uses mechanical true bypass switching.
- Power : This device takes a standard 500 mA (or higher) 9-volt DC power supply with a 2.1 mm negative-center barrel. We always recommend pedal-specific, transformer-isolated wall-wart power supplies or multiple isolated-output supplies. Pedals will make extra noise if there is ripple or unclean power. Switching-type power supplies, daisy chains, and non-pedal specific power supplies do not filter dirty power as well and let through unwanted noise. DO NOT RUN AT HIGHER VOLTAGES!
