The GUPtech Slime Mid-Boost is a compact pedal that works as both a midrange boost and a one-band parametric EQ. GUPtech describes it as "a compact, no-nonsense midrange weapon built to push your tone exactly where it needs to sit in the mix"1. The circuit is based on the mid section of the company's GUPtech pPTSD parametric EQ, so it takes the part of that pedal most players reach for most often and puts it in its own box1.
Controls
The Slime gives you a single fully sweepable mid band with level control, and the three knobs cover the three things a parametric band needs1.
| Control | What it does |
|---|---|
| Frequency | Selects between 250 up to 2.5k frequencies to tweak1 |
| Gain | A "remove", unity at noon, "Boost" knob, used to remove or add the desired frequency1 |
| Focus | A "narrow" to "large" bandwidth control1 |
| Volume | A post-EQ volume used to control the overall pedal volume, unity around noon1 |
The Gain knob working both ways is worth noting: with unity at noon, turning it down cuts the selected frequency and turning it up boosts it, so the Slime can scoop a problem mid as well as push one forward. The Focus knob then sets how wide a region around that frequency is affected, from a narrow slice to a large band1.
Sound and use
GUPtech says the pedal "is aptly named because it has a somewhat gooey quality when used as a boost"1. As for how players are putting it to work, the maker quotes one user, Jerome: "I use my Guptech parametric 3-band EQ so much that I wished for a fourth band and here it is."1 That is the intended role: a fourth, independent mid band alongside a larger EQ, or a standalone mid shaper on a board that has no EQ at all. For more pedals in this family, see Boost Pedals and the GUPtech Le Chiou EQ-Boost.
Slime Mid-Boost Gold Rush Edition
The Slime Mid-Boost Gold Rush Edition is a variant with exactly the same circuit as the original GUPtech Slime, in a unique Gold box2. GUPtech lists it as a boost pedal, the "Unique Gold Rush Edition Slime Boost"2.
The Gold Rush Edition was listed as sold out on GUPtech's product page as of October 20262.
Videos
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Questions
What frequency range does the GUPtech Slime Mid-Boost cover?
The Frequency knob lets you select between 250 up to 2.5k frequencies to tweak, according to GUPtech. That covers the core of a guitar's midrange, from low-mid warmth up into the upper-mid region where a part either sits in the mix or disappears into it. Combined with the Gain and Focus knobs, it gives you a single fully sweepable mid band with level control.
What power does the GUPtech Slime Mid-Boost need?
GUPtech lists the power requirements as 9V DC center negative with a 6mA consumption. That low draw means it sits comfortably on any standard pedalboard power supply without worrying about current budgets.
Where is the GUPtech Slime Mid-Boost made?
GUPtech describes the Slime Mid-Boost as boutique handmade construction in Saguenay, Quebec, Canada. The pedal is built to order by the maker rather than mass produced.
What is the Slime Mid-Boost Gold Rush Edition?
The Gold Rush Edition is a version of the Slime Mid-Boost with exactly the same circuit as the original GUPtech Slime, housed in a unique Gold box. GUPtech lists it as a boost pedal. It was sold out as of the maker's product page in October 2026.
Is the Slime Mid-Boost a parametric EQ?
Yes. GUPtech lists it as a 1-band Parametric EQ. It gives you one fully sweepable mid band with level control, and the three knobs (Frequency, Gain and Focus) cover the three things a parametric band controls: which frequency, how much of it, and how wide the affected region is.
Sources (2)
- Slime Mid-Boost, GUPtech
- Slime Mid-Boost, guptech.ca
