The JAM Pedals Rattler 2 (also sold as the Rattler mk.2) is a distortion pedal built on the RAT circuit, updated in July 2024 with three major changes over the original Rattler: a footswitchable mid boost, a two-way symmetrical/asymmetrical clipping toggle, and a proprietary custom op amp chip in place of the scarce LM308 chip used in earlier units12. It is made by JAM Pedals, entirely hand-made and hand-finished, including a paint job with unique diagonal strokes on each pedal1.
The mk.2 sits somewhere between the original Rattler and the Custom Shop Rattler+ in character, with the tin-can op amp Rattler+ being a touch smoother in its output1. Guitar Pedal X's reviewer, who owned both a Standard Rattler and a Rattler+ before the mk.2, called the new version "a little smoother and more refined" than its predecessor3.
What it does and how it is controlled
On the outside the Rattler 2 keeps the classic RAT control set: Level, Gain and Tone knobs, plus two footswitches, one for the main Rattler bypass and one for the Mid Boost15. The clipping choice and the boost adjustments live inside the enclosure.
| Control | What it does |
|---|---|
| Level | Output volume |
| Gain | Distortion amount |
| Tone | High-frequency roll-off |
| Clipping toggle (internal) | Asymmetrical (up) or symmetrical (down, marked S) |
| Mid Boost footswitch | Engages the mid boost on top of the base tone |
| Bypass footswitch | Turns the Rattler circuit on and off |
Guitar Pedal X's reviewer settled on Level at 3 o'clock, Gain at 3 o'clock and Tone at 2 o'clock on his own unit1.
The Mid Boost and the internal trimmers
The Mid Boost is the headline addition of the mk.2. It is engaged by its own second footswitch, and its character can be tuned inside the pedal14:
- A Trim-pot for the Mid Boost Level, default set somewhat in the middle, adjusts the intensity and output of the boost1.
- An internal low-cut switch lets you cut or include the low end of the boosted signal; switch down is low-cut4.
- A Fat Boost Dip-Switch, default set on, adds fatness to the boost and can be cut back if you do not want it1.
Symmetrical and asymmetrical clipping
The internal clipping toggle-switch selects between two diode-clipping configurations14:
- Asymmetrical (switch up): the reviewer at Guitar Pedal X found this the richer, more textured setting, and his preferred side of the switch1.
- Symmetrical (switch down, marked S): makes the output somewhat smoother1.
The same two-way clipping option was recently included on JAM Pedals' Octaurus Octafuzz, so players familiar with that pedal will recognize the switch4.
The custom op amp
The original Rattler used the LM308 chip, which became scarce, so the mk.2 replaces it with a JAM Pedals proprietary custom OpAmp chip3. JAM Pedals says the custom chip "preserves the open, dynamic, and tube-amp feel that made the original Rattler so revered"4. In practice, Guitar Pedal X's reviewer found the new op amp "overall a touch more refined and less raspy" than the earlier circuit1.
Power-up modes
The Rattler 2 remembers which of its two circuits should be on when you power it up. Holding the footswitch at power-up cycles through four startup combinations1:
- Rattler Off, Boost Off
- Rattler On, Boost On
- Rattler Off, Boost On
- Rattler On, Boost Off
This lets a player, for example, set the pedal to come up with the boost already engaged, or with the whole effect bypassed.
Versions and the bass model
Every Rattler 2 is entirely hand-made and finished, including the paint job, with unique diagonal strokes on each pedal1. The circuit sits somewhere between the original Rattler and the Custom Shop Rattler+, JAM Pedals' two earlier versions of the pedal, the Standard Rattler and the Rattler+13.
Nels Cline is listed among JAM Pedals' artists as a Rattler user6.
What reviewers said
Guitar Pedal X reviewed the pedal at length when it landed at dealers in July 20241:
"have always considered it one of the very finest Rats in terms of its rich texture and beautifully balanced output"
The same reviewer concluded that the mk.2 "wholly lives up to the legacy" of the original, while noting the new op amp makes it a touch more refined and less raspy1. A second reviewer, who already owned the Standard Rattler and the Rattler+, found this version "a little smoother and more refined" than its predecessor3. ===
By July 2024 the pedal had already shipped in some numbers, with the reviewer's own unit referenced #0459, and it was available at international dealers as well as the JAM Pedals webstore at $2491.
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Questions
What is the difference between symmetrical and asymmetrical clipping on the Rattler 2?
An internal toggle-switch selects between the two. In the up position the pedal clips asymmetrical, which the reviewing player at Guitar Pedal X found richer and more textured. With the switch down (marked S) the clipping is symmetrical, which makes the output somewhat smoother. It is the same two-way clipping option JAM Pedals recently used on its Octaurus Octafuzz.
What op amp does the JAM Rattler 2 use?
The Rattler 2 uses a JAM Pedals proprietary custom OpAmp chip rather than the LM308 chip of the original, which had become scarce. JAM Pedals says the custom chip preserves the open, dynamic, tube-amp feel that made the original Rattler so revered, and reviewers found the new version a touch more refined and less raspy than its predecessor.
Is there a bass version of the Rattler mk.2?
Yes. JAM Pedals makes the Achenbach Rattler Bass mk.2, a bass version of the same mk.2 circuit, alongside the standard guitar versions. The bass version was announced at the same time as the guitar Rattler 2 in July 2024.
How do I set the Rattler 2 to start with the boost on?
The pedal stores a startup state for both the Rattler and the boost, cycled by holding the footswitch while powering it up. The four available combinations are Rattler Off with Boost Off, Rattler On with Boost On, Rattler Off with Boost On, and Rattler On with Boost Off. Hold the footswitch at power-up until the combination you want is set.
Sources (6)
- Guitar Pedal X, Guitar Pedal X, 2024-07-25
- Jam Pedals Rattler Mk.2 Distortion, Delicious Audio, 2025-03-17
- Guitar Pedal X, Guitar Pedal X, 2024-08-30
- Guitar Pedal X, Guitar Pedal X, 2024-07-18
- Guitar Pedal X, Guitar Pedal X, 2024-12-17
- Nels Cline (Wilco), JAM Pedals
