The "Moonrock" Rattler mk.2 is a distortion pedal from JAM Pedals, the Greek maker's updated take on the Rat-style circuit. The mk.2 adds two things the original Rattler did not have: a second footswitch that brings in a mid boost ahead of the distortion, and a switch that selects between two clipping voices. Inside, JAM uses a proprietary discrete-component op-amp the company developed to preserve what it describes as the open, dynamic and tube-amp-like feel associated with the discontinued LM308 chip1.
"Moonrock" is the name of this pedal's finish, not a different circuit. JAM sells the Rattler mk.2 across a series of custom artwork versions, each hand-painted and each with the same sound and controls1.
Every limited artwork pedal is a one-of-a-kind hand-painted piece, and JAM notes that the pedal received will differ in detail from the photos shown on its product page1.
What it does to your signal
The Rattler mk.2 runs a distortion stage with a mid boost available in front of it. The clipping voice switch chooses between the two voices: the top position selects the original asymmetrical clipping, and the bottom position selects symmetrical clipping, which JAM says gives a different feel and compression profile1. Players who know the Rat family will recognize the asymmetrical setting as the traditional voice; the symmetrical option is the mk.2's addition.
The left footswitch engages the mid boost before the distortion1. Because the boost feeds the clipping stage, it increases saturation as well as adding midrange, which is the usual way a boost-before-distortion arrangement behaves. How hard it pushes is set internally, not from the floor.
The controls
| Control | What it does |
|---|---|
| Gain | Sets saturation1 |
| Tone | Shapes the frequency response1 |
| Level | Sets output level1 |
| Clipping voice switch | Top position selects original asymmetrical clipping; bottom position selects symmetrical clipping for a different feel and compression profile1 |
| Left footswitch | Engages the mid boost before the distortion1 |
Two further adjustments live inside the pedal:
- An internal trimmer sets the mid boost level1
- An internal DIP switch keeps the full low end or applies a low cut for a tighter sound1
The 95 mA current draw means the Rattler mk.2 needs a power supply output that can deliver it. On a pedalboard with a shared or daisy-chained supply, budget for the full 95 mA against that output's rating1.
The Rattler mk.2 family
JAM sells the mk.2 circuit across a set of hand-painted artwork versions, described by the maker as the same sound with different artwork1:
- "Moonrock" Rattler mk.2 (this pedal)1
- "Batkin" Rattler mk.21
- "Monterey" Rattler mk.21
- "Ophis" Rattler mk.21
- "Achenbach" Rattler mk21,2
- "Neurones" Rattler mk.2 (sold out)1,3
There is also a bass version, the "Achenbach" Rattler Bass mk.2, a distortion pedal on the same mk.2 platform voiced for bass4. For the earlier, non-mk.2 circuit, see the JAM Pedals Rattler and the Rattler 2.
Buying direct from JAM
JAM ships the pedal free, DDP, with 20% UK VAT and all duties included and no extra charges on delivery1. The maker's return policy allows a refund within 30 days of receiving the product if you are not satisfied, no questions asked1.
Questions
Is the JAM Rattler mk.2 true bypass?
Yes. JAM Pedals lists the "Moonrock" Rattler mk.2 with true bypass, so the pedal is removed from your signal chain entirely when it is switched off. The maker also specifies an input impedance of 500 kΩ and an output impedance of under 5 kΩ, figures that matter if you run long cable runs or place the pedal before or after other effects on your board.
What does the left footswitch do on the Rattler mk.2?
The left footswitch engages a mid boost that sits before the distortion stage. That pushes the clipping harder and brings the guitar forward in a band mix without changing the pedal's main gain setting. The amount of boost is not on an external knob: it is set with an internal trimmer, so you dial it in once with a small screwdriver and then call it up from the floor.
How do I change the mid boost level or the low cut?
Both are inside the pedal. An internal trimmer sets the mid boost level, and an internal DIP switch chooses between keeping the full low end and applying a low cut for a tighter sound. You will need to take the back plate off to reach them, so most players set them at home rather than mid-gig.
Is the Moonrock Rattler mk.2 different in sound from the standard one?
No. JAM Pedals describes the artwork versions of the Rattler mk.2 as the same sound with different artwork. "Moonrock" is one of several hand-painted variants alongside "Batkin", "Monterey", "Ophis", "Achenbach" and "Neurones", and the circuit, controls and features are the same across the range.
Does the Moonrock Rattler mk.2 run on a battery?
JAM Pedals specifies 9V DC centre-negative power with a current draw of 95 mA. That draw is high enough that a dedicated power supply output, rather than a shared daisy chain, is the practical way to run it on a pedalboard. Check your supply's per-output budget against the 95 mA figure before slotting it in.
Is there a bass version of the Rattler mk.2?
Yes. Alongside the guitar artwork versions, JAM Pedals makes the "Achenbach" Rattler Bass mk.2, a distortion pedal built on the same mk.2 Rattler platform but voiced for bass. It sits in the maker's range next to the guitar versions rather than as an afterthought, and it carries the mk.2 designation in its own right.
Sources (4)
- "Moonrock" Rattler mk.2, JAM pedals
- “Achenbach” Rattler mk2., JAM Pedals (jampedals.com)
- “Neurones” Rattler mk.2, JAM pedals (www.jampedals.com)
- “Achenbach” Rattler Bass mk.2, JAM Pedals (jampedals.com)
