The JHS MiniBomb, sold as the Mini Bomb Boost, is a compact JFET boost pedal from JHS Pedals. It is a simple clean boost built around JFET transistors, with a single Boost knob, and it takes up what JHS describes as "a small 1.5\"x3.5\" spot on your pedal board"1. The pedal is discontinued: JHS says plainly, "Sad to say, these aren't made anymore"2.
What it does to your sound
JHS describes the Mini Bomb Boost as a booster with "a huge amount of headroom that can cause a tube amp to naturally overdrive," which the maker calls great for lead passages3. Where you put it in the chain changes what it does:
- Before overdrives or distortions: JHS says "a thicker, stronger and more saturated tone can be achieved"3
- After overdrives or distortions: the same tone, simply louder, with a slight touch of presence3
- Into a tube amp: enough headroom to push the amp into natural overdrive3
The Boost knob is a volume pot at the input of the circuit. Guitar FX Layouts notes that the input goes straight to the JFET with no input capacitor, and that at full counterclockwise the gate of the FET is shunted to ground completely, so there is no sound4.
The circuit
The MiniBomb's circuit is a single-JFET design. Guitar FX Layouts, which traced the layout, found it identical to the Escobedo Duende JFET boost: "The circuit for these two are verbatim." The difference between the two is biasing: "Escobedo just has a trimmer to bias the JFET, where JHS has 5K1 resistor"4.
| JHS MiniBomb | Escobedo Duende JFET | |
|---|---|---|
| Circuit | Identical4 | Identical4 |
| Biasing | Fixed 5K1 resistor4 | Trimmer to bias the JFET4 |
On the transistors, the analysis reads "He probably uses matched j201s," identifying J201 JFETs, likely matched, as the design's parts4. Builders reproducing the circuit on the same page report success with substitutes: one built it with a 2N5457 and another with a BF245A4.
A builder on Guitar FX Layouts warned against the fixed-resistor version without a trimpot: "Also if anyone wants to build this don't bother with the one without the trimpot. I built that one first and it was quieter than the bypassed signal." In the trimmer version, the advice is to measure the voltage between the drain pin of the FET and ground and adjust the trimmer until it reads about 4.5V4.
What builders and players found
Because the pedal is out of production, most detailed listening impressions come from builders who reproduced the circuit and from players who kept one on a board24:
- One builder found it "much better clean boost at first glance than the SHO clone," though "not nearly as raunchy," and described it as very transparent and quiet with added sparkle4.
- Another, using a 2N5457, reported it "sounds amazing! Much fuller and more boost than my LPB1"4.
- A builder using a BF245A found it "a cool little circuit" that adds a tiny bit of noise but makes a darker sounding amp richer and brings presence; it stayed always on for that player4.
- One builder measured unity volume at around 11 o'clock on the knob, found it has lots of headroom, and noted it can get slightly boomy as a full range boost4.
- Another found the MiniBomb makes a Strat warmer, louder, and with a nice top sparkle, replacing an LPB-1 boost on that board4.
On the question of supply voltage, a commenter on the Guitar FX Layouts page asked whether the circuit can run at 18 volts, and the answer given there was that it can pretty well run at 18 volts4.
JHS's own history article on boost pedals notes one player who never took his off the board: "Jared Sharp from SNL still uses this. I believe it's been on his board for a long, long time"2.
The hand-painted edition
JHS offered a hand-painted edition of the Mini Bomb Boost, listed on the maker's product pages as "MINI BOMB BOOST HAND PAINT"3.
Where it fits in JHS's boost range
With the MiniBomb discontinued, players looking at one secondhand are shopping for a small, transparent single-knob boost: the circuit takes up what JHS describes as "a small 1.5\"x3.5" spot on your pedal board"234, and the company's product page calls a good booster "often the most underrated tool a guitarist can own"3. Builders who have put the circuit together place it alongside other simple boosts: one found it a "much better clean boost at first glance than the SHO clone," though "not nearly as raunchy"4, and another reported it "much fuller and more boost than my LPB1"4.
Videos
Curtis Kent
Stairwaytoodevin
Curtis Kent
Questions
Is the JHS MiniBomb discontinued?
Yes. JHS Pedals says plainly that the Mini Bomb Boost is not made anymore. The pedal still turns up used and on players' boards, and JHS has continued the idea of a simple JFET boost in later pedals such as the Fumble, released in June 2026.
What circuit is the JHS MiniBomb based on?
The Guitar FX Layouts technical analysis found the MiniBomb's circuit to be identical to the Escobedo Duende JFET boost, describing the two as verbatim the same circuit. The difference is in the biasing: Escobedo's design uses a trimmer to bias the JFET, while the JHS version uses a fixed 5K1 resistor.
Should the MiniBomb go before or after overdrive?
JHS describes both placements as useful. Before your overdrives or distortions, the pedal pushes them into a thicker, stronger and more saturated tone. Placed after, it gives the same tone simply louder, with a slight touch of presence. It also has enough headroom to push a tube amp into natural overdrive on its own.
Was there a hand-painted JHS Mini Bomb Boost?
Yes. JHS offered a hand-painted edition of the Mini Bomb Boost, listed on the maker's own product pages alongside the standard version.
What JFET does the MiniBomb use?
The Guitar FX Layouts analysis of the circuit identifies J201 JFETs, likely matched pairs, as the transistors in the design. Builders on the same page also report good results substituting other JFETs such as the 2N5457 and BF245A in their own builds.
Sources (4)
- MINI BOMB BOOST HAND PAINT, JHS Pedals
- WHY YOU NEED BOOST PEDALS, JHS Pedals
- MINI BOMB BOOST HAND PAINT, JHS Pedals
- Guitar FX Layouts: Escobedo Duende JFET = JHS MiniBomb, Guitar FX Layouts (tagboardeffects.blogspot.com), 2013-04-28
