The JAM Pedals "Achenbach" Rattler mk2 is a limited-artwork version of JAM Pedals' Rattler 2 distortion pedal, painted by The Simpsons artist John Achenbach. JAM Pedals describes the Rattler as "a bold, open and dynamic distortion pedal that channels the fat, creamy voice of classic early-'80s circuits through a custom discrete-component op-amp"1. The circuit is a Rat-style design: the Rattler Bass version of the same family is described by the maker as inspired by the sound of the late '80s ProCo RAT2.
The mk2 keeps what JAM Pedals calls the tube-like response of the original Rattler while adding clickless switching, a footswitchable mid boost and expanded control over clipping and midrange1. The "Achenbach" version is sold out at the maker's webstore3, and every limited artwork pedal is a one-of-a-kind hand-painted piece, so no two look identical1.
The controls and the mid boost
Three knobs sit on top: Level sets output, Tone shapes the frequency balance, and Gain controls fuzz intensity1. Guitar Pedal X's rundown of the Rattler MK2 lists the full control set as "Level, Gain, Tone, Clipping : Asymmetrical / Symmetrical, Mid Boost Footswitch, Bypass Footswitch"4.
The left footswitch engages a mid boost before the distortion stage1. Two internal adjustments shape that boost:
- An internal trimmer sets the boost level1.
- An internal DIP switch keeps the full low end, or applies a low cut for a tighter sound1.
A clipping switch offers two saturation profiles: the top position selects the original asymmetrical clipping, and the bottom position selects symmetrical clipping for a different feel and compression profile1. JAM Pedals also describes two frequency voices: scooped mode tightens the response and emphasises the octave effect, while full-range mode retains more harmonic body for lead work1.
| Control | What it does |
|---|---|
| Level | Sets output1 |
| Tone | Shapes the frequency balance1 |
| Gain | Controls fuzz intensity1 |
| Clipping switch | Top: original asymmetrical clipping; bottom: symmetrical clipping1 |
| Left footswitch | Engages a mid boost before the distortion1 |
| Right footswitch | Bypass4 |
| Internal trimmer | Sets mid boost level1 |
| Internal DIP switch | Full low end or low cut for a tighter sound1 |
Power and connections
The "Achenbach" Rattler mk2 runs on 9V DC, center-negative, with a current draw of 95 mA1. There is no battery option on the mk2, unlike the handwired Rattler ltd, which takes a 9V battery or 9V DC, center-negative, and draws only 6 mA5.
At 95 mA the mk2 draws noticeably more current than the 6 mA Rattler ltd15. Input impedance is 500 kΩ and output impedance is under 5 kΩ1.
JAM Pedals ships the pedal DDP, with 20% UK VAT and all duties included and no extra charges on delivery, and offers a 30-day money-back guarantee with a refund, no questions asked, if you are not satisfied1.
The Achenbach artwork and the handwired Rattler ltd
The artwork on this version is by John Achenbach, the artist JAM Pedals credits as a Simpsons artist5. Every limited artwork pedal is a one-of-a-kind hand-painted piece, and the pedal you receive will differ in detail from the photos shown1. The same mk2 circuit appears in other custom artwork versions, which JAM Pedals sums up as "same sound, different artwork": the "Moonrock" Rattler mk.2 and "Neurones" Rattler mk.2, plus "Batkin", "Monterey" and "Ophis" versions1. There is also an "Achenbach" Rattler Bass mk.2 for bass players, a bass-adjusted variant of the same distortion2.
The Rattler ltd is a different, more elaborate build. JAM Pedals describes it as "our limited-edition, vintage-voiced distortion, reimagined through the artwork of The Simpsons artist John Achenbach"5. Where the mk2 uses JAM's proprietary discrete-component op-amp, developed to preserve the open, dynamic and tube-amp-like feel associated with the discontinued LM3081, the ltd is built around what the maker calls the exceptionally rare NOS LM308AH metal-can chip for authentic vintage character with modern clarity5.
| "Achenbach" Rattler mk2 | "Achenbach" Rattler ltd | |
|---|---|---|
| Op-amp | Custom discrete-component op-amp1 | NOS LM308AH metal-can5 |
| Construction | Standard5 | Point-to-point wiring, carbon-composition resistors, tropical-fish capacitors, faux-leather enclosure5 |
| Clipping | Switchable: asymmetrical or symmetrical1 | Symmetrical, smoother and slightly less aggressive than the standard Rattler5 |
| Gain modes | Gain knob1 | Toggle: high gain right, lower gain left; low-gain is more open, less compressed, closer to overdrive5 |
| Mid boost | Footswitchable, with internal trimmer and low-end DIP switch1 | Not listed |
| Power | 9V DC center-negative, 95 mA1 | 9V battery or 9V DC center-negative, 6 mA5 |
| Bypass | True bypass1 | True bypass5 |
| List price | £294.00 GBP1 | £464.00 GBP5 |
Guitarist Tim Miller, quoted on the maker's page, gives his view of the ltd5:
"The JAM Rattler LTD is an exceptional distortion/overdrive pedal. It has a wide range of distortion tones and responds very well to my playing dynamics."
Both versions carry the same 30-day money-back guarantee and DDP shipping terms15.
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Questions
Who painted the Achenbach Rattler?
The artwork is by John Achenbach, an artist known for his work on The Simpsons. JAM Pedals describes the Rattler ltd as its vintage-voiced distortion reimagined through his artwork. Every limited artwork pedal is a one-of-a-kind hand-painted piece, so the pedal you receive will differ in detail from the photos shown.
Is the Achenbach Rattler mk2 still available?
No. JAM Pedals lists the "Achenbach" Rattler mk2 as sold out. The same circuit is also offered in other custom artwork versions such as the "Batkin", "Monterey", "Moonrock" and "Ophis" Rattler mk.2, which JAM Pedals describes as same sound, different artwork.
What is the difference between the Rattler mk2 and the Rattler ltd?
The mk2 uses a custom discrete-component op-amp that JAM Pedals developed to preserve the feel of the discontinued LM308, with a clipping switch and a footswitchable mid boost. The ltd is handwired point-to-point around a rare NOS LM308AH metal-can chip, uses symmetrical clipping with a high/low gain toggle, and draws 6 mA instead of 95 mA.
Can the Rattler ltd run on a 9V battery?
Yes. JAM Pedals lists the Rattler ltd's power as a 9V battery or 9V DC, centre-negative. The mk2 version runs on 9V DC, centre-negative only, with a current draw of 95 mA, so it has no battery option.
What op-amp is in the JAM Rattler ltd?
The Rattler ltd is built around the NOS LM308AH metal-can op-amp, which JAM Pedals describes as exceptionally rare and chosen for authentic vintage character with modern clarity. The standard Rattler mk2 instead uses a proprietary discrete-component op-amp designed to preserve the open, dynamic, tube-amp-like feel associated with the discontinued LM308.
Sources (5)
- “Achenbach” Rattler mk2., JAM Pedals (jampedals.com)
- “Achenbach” Rattler Bass mk.2, JAM Pedals (jampedals.com)
- Rattler, JAM pedals (www.jampedals.com)
- Guitar Pedal X, Guitar Pedal X, 2024-12-17
- “Achenbach” Rattler ltd, JAM Pedals (www.jampedals.com)
Duke Levine
