JAM Pedals makes the "Achenbach" Fuzz Phrase Si, a limited-artwork edition of its silicon fuzz circuit. The Greek builder describes it as "Our warm, dynamic silicon fuzz, reimagined through the artwork of The Simpsons artist John Achenbach"1. Under the paint it is the Fuzz Phrase Si, the BC107-loaded silicon take on the circuit that JAM Pedals first built with germanium transistors1.
The circuit: silicon where the original was germanium
The Fuzz Phrase Si is JAM Pedals' silicon take on the Fuzz Phrase circuit, and the maker's own page for the pedal sets out what that means in practice. It carries a single Gain knob, which sets the amount of gain, and runs on a 9V battery or a 9V DC adaptor with tip-negative polarity, with a power consumption of 3 mA1. The maker also lists its physical details: 7.5 x 12 x 5.6 cm / 2.9 x 4.7 x 2.2 inches with jacks and pots included, and a weight of 250g / 0.55 lbs1.
For players, the practical details are on the maker's page. The Si works with a 9V battery or a 9V DC adaptor (tip-negative) and draws 3 mA, so it sits lightly on a pedalboard's power supply1. Its single Gain control sets the amount of gain1. JAM Pedals backs the pedal with a money-back guarantee: a refund within 30 days of receiving the product if not satisfied, no questions asked1.
Controls
| Control | What it does |
|---|---|
| Gain | Sets the amount of gain1 |
| Level | Adjusts output volume, while also allowing for versatile tonal shaping1 |
| Internal Trimmer | Sets transistor bias, factory-set at 4.5V1 |
The internal trimmer is the one control that lives under the lid. Because it sets the bias of the BC107s, it shapes how the transistors clip and how the fuzz responds to playing dynamics. JAM Pedals ships it set at 4.5V, so the pedal arrives ready to play1.
Power and practicalities
The adaptor polarity is tip-negative, which is the standard for most pedal supplies, but check your supply's polarity marking before plugging in a fuzz.
- Runs on a 9V battery or a 9V DC adaptor, tip-negative1
- Power consumption: 3 mA1
- True bypass switching1
- Money-back guarantee: refund within 30 days of receiving the product if not satisfied, no questions asked1
At 3 mA the Fuzz Phrase Si is a light load on a power supply, and the battery option makes it straightforward to run without a dedicated outlet1.
The Achenbach Series artwork
The Achenbach Series is a line of limited pedals whose artwork comes from John Achenbach, an artist known for his work on The Simpsons. JAM Pedals describes the series as "the result of a loving friendship that has developed through the years out of mutual respect" between the maker and the artist1. Every limited artwork pedal is a one-of-a-kind hand-painted piece, and the maker is clear that the pedal a buyer receives will differ in detail from the photos shown1.
The Fuzz Phrase Si appears in several custom artwork versions, all sharing the same circuit and sound1:
| Version | Page |
|---|---|
| "Bad TV" | JAM Pedals "Bad TV" Fuzz Phrase Si |
| "Black Data" | JAM Pedals "Black Data" Fuzz Phrase Si |
| "IT" | JAM Pedals "IT" Fuzz Phrase Si |
| "Luminous" | JAM Pedals "Luminous" Fuzz Phrase Si |
| "Mandala" | JAM Pedals "Mandala" Fuzz Phrase Si |
| "Relic" | JAM Pedals "Relic" Fuzz Phrase Si |
| "Shards" | JAM Pedals "Shards" Fuzz Phrase Si |
JAM Pedals sums up the relationship between them as "Same sound, different artwork"1. The Achenbach treatment extends beyond the Fuzz Phrase Si to other circuits in the range, including the "Achenbach" Octaurus and the "Achenbach" Octaurus NOS1.
Where it sits in the JAM fuzz range
Players comparing fuzzes within the JAM Pedals line can start from the maker's page for the Fuzz Phrase Si, which lists the pedal's controls, power requirements, dimensions and its 30-day money-back guarantee1. For a broader view of the effect type, see Fuzz Pedals.
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Questions
Is the JAM Pedals Achenbach Fuzz Phrase Si true bypass?
Yes. JAM Pedals lists the Achenbach Fuzz Phrase Si as true bypass, so the pedal takes itself fully out of the signal chain when switched off. It runs on a 9V battery or a 9V DC adaptor with a tip-negative plug and draws 3 mA, which is light enough for almost any pedalboard power supply.
What does the internal trimmer do on the Fuzz Phrase Si?
The internal trimmer sets the transistor bias, which JAM Pedals factory-sets at 4.5V. Bias shapes how the silicon transistors clip, so it affects the fuzz's texture and response. JAM Pedals describes the Level knob as also allowing for versatile tonal shaping alongside its main job of setting output volume.
What transistors does the Fuzz Phrase Si use?
The Fuzz Phrase Si uses BC107 silicon transistors. JAM Pedals says that after testing various silicon transistors, the BC107s emerged as its choice for the circuit, which draws inspiration from the germanium Fuzz Phrase Ltd.
Is every Achenbach Fuzz Phrase Si painted differently?
Yes. JAM Pedals states that every limited artwork pedal is a one-of-a-kind hand-painted piece, and the pedal a buyer receives will differ in detail from the photos shown. The Achenbach Series artwork comes from The Simpsons artist John Achenbach.
What is the difference between the Fuzz Phrase Si and the germanium Fuzz Phrase?
The Fuzz Phrase Si is the silicon version of the circuit, built with BC107 transistors, while the original Fuzz Phrase and the Fuzz Phrase Ltd are germanium-based. JAM Pedals describes the Si as drawing inspiration from its germanium predecessor and aiming to keep the rich harmonic profile and dynamic response of that circuit.
Sources (2)
- “Achenbach” Fuzz Phrase Si (silicon fuzz), JAM Pedals (jampedals.com)
- Fuzz Phrase Si, JAM Pedals (www.jampedals.com)
