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.
Practice Amp with Headphones
The headphone output features built-in analog cabinet simulation for a realistic amp feel during quiet practice sessions. Enjoy the full EF86 tube character without disturbing your housemates.
Run the balanced XLR output straight into any console or interface and use the ZEQD-Pre as your main amp. The analog cabinet simulation is there when you need it, or flip the Cab Bypass switch to send a pure signal to your preferred IR loader or modeling software. Perfect for direct recording, backline-free gigs, or hybrid rigs with multiple signal paths.
All outputs work simultaneously, even when the pedal is bypassed. Send your signal to an amp, route a direct feed to front-of-house, and monitor through headphones—all at once. This routing flexibility makes the ZEQD-Pre an invaluable studio tool.
Why The EF86 Tube?
The ZEQD-Pre uses the EF86 pentode—the same tube that gives many Dr. Z amplifiers their pristine hi-fi tone and makes them such responsive pedal platforms.
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:
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Gain Factor of 185: Significantly higher than comparable triodes
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44V RMS Output: Substantial voltage swing for enhanced dynamics
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Extended Frequency Response: Full-spectrum clarity from deep lows to detailed highs
What This Means for You
These specifications translate directly to playing experience:
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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.
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Full-Frequency Clarity: Extended response means harmonic richness without sacrificing definition. Bass notes stay tight, highs remain bell-like and clear.
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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.
1 – All claims require a purchase receipt. It is the customer's responsibility to present it when making a claim.
2 – Except as stated below, in-store sales are final and items purchased may not be returned. By completing their transaction, the customer acknowledges that they have taken the item(s) in optimal condition.
3 – Guitars, basses, pedals, amplifiers, accessories, and tubes are not returnable. By paying for the item, the customer acknowledges that: (i) they inspected it and found it to be in optimal aesthetic condition without defects; and (ii) they tested it and it was functioning properly.
4 – All claims due to defects are subject to the manufacturer’s terms and conditions.
5 – Guitars, basses, pedals, and amplifiers will have a 30-day warranty. The electronics of guitars and basses will have a 90-day warranty. Guitars Boutique, at its sole discretion, will decide whether to repair, replace parts or components (with identical ones), and/or replace the item with an identical one.
6 – At the store's discretion, defective items may be exchanged for an identical item SUBJECT to the defective item being in the same condition as when it was acquired, including its original packaging with all its accessories. This will be done as store credit only. The credit does not apply to special orders or lay-away.
7 – All merchandise leaving the store will be considered as used in the future.
8 – No refunds will be given, regardless of the person.
9 – Special, clearance, or discounted items are not returnable.
Puerto Rico only.
In case of a return, the shipping cost will be deducted from the refund.
Guitars Boutique ships to PR via federal mail USPS, UVA, and iWide.
Estimated delivery time once the order has been shipped:
- Lightweight items, less than 14 pounds are shipped via USPS.
- Heavier items are shipped via iWide and UVA.
- No shipments are made on Sundays.
Guitars Boutique is not responsible for delays caused by shipping companies.
