The MXR Echoplex Preamp is a stompbox preamp that recreates the preamp section of the original Maestro Echoplex EP-3 tape delay. That old unit's preamp was prized on its own for the color and bite it added to a guitar signal, and Dunlop says the pedal "recreates the EP-3's legendary preamp mojo, following the same signal path with FET circuitry"1. It sits in the wider family of preamp pedals, alongside Dunlop's own Dunlop Echoplex Preamp and Dunlop EP101 Echoplex Preamp pages on this site.
What it does
The pedal does two things at once. Guitar World's review video described it this way: "In addition to providing a few dB of gain, it affects the phase response of different frequencies to make a guitar sound" bolder and more focused3. In practice that means it is not a boost in the plain sense: it shapes the signal as it lifts it, which is why players reach for it in front of an amp rather than as a clean volume push.
The circuit's heritage matters to the sound. The original EP-3 ran its preamp from a 20V supply internally, a figure Aion FX cites when describing the design the pedal follows4. Premier Guitar's reviewer summed up the pedal's overdrive character plainly: "Like the preamp it replicates, the pedal delivers relatively subtle overdrive"2.
Controls
The pedal keeps things deliberately minimal, with a single Gain knob.
| Control | What it does |
|---|---|
| Gain | Sets the amount of preamp gain. From position 7 and above, the pedal produces light overdrive clipping, per the Dunlop manual5 |
That single-knob layout is a large part of the appeal for reviewers. Premier Guitar's reviewer called it "Incredibly easy to use" and described it as "a sturdy, elegant, and stupidly simple stompbox"2.
What reviewers found
Premier Guitar's reviewer put the pedal to work on a real session, using it with an old Fender Vibro Champ for Crazy Horse-style grind on a rhythm guitar track2. The review's test gear covered a spread of guitars and amps: a Squier J Mascis Jazzmaster, an '80s '52 Reissue Fender Telecaster, a '64 Fender Tremolux and a '70s Fender Vibro Champ2.
Videos
Guitar World
Rob Chapman
GAK
Questions
What is the MXR Echoplex Preamp based on?
It is based on the preamp section of the original Maestro Echoplex EP-3 tape delay. Players used that unit partly for the color and bite its preamp added, and Dunlop says the pedal follows the same signal path using FET circuitry. Aion FX notes the design compares to the 20V supply of the original unit.
Is the Echoplex Preamp an overdrive pedal?
Not primarily. Premier Guitar's reviewer described its overdrive as relatively subtle, like the preamp it replicates. The Dunlop manual notes that from Gain knob position 7 and above the pedal produces light overdrive clipping, so it can push into mild breakup, but its main job is preamp color and gain.
Sources (5)
- ECHOPLEX® PREAMP, Dunlop (jimdunlop.com)
- Quick Hit: MXR Echoplex Preamp Mini Review, Premier Guitar, 2014-06-09
- Review: Dunlop EP101 Echoplex Preamp, Guitar World, 2014-06-19
- Ares Vintage Preamp / Echoplex EP-3 Preamp, Aion FX, 2019-10-18
- EP101.pdf, Dunlop Manufacturing, Inc., 2019
