The Keeley Tesla MK III is a fuzz pedal built around a germanium transistor with origins in the Soviet Union, announced in June 2017. Robert Keeley's design is a fuzz in the style of a Tonebender, the 1960s circuit whose sputtery, compressed character germanium transistors are known for. The pedal is a limited edition: only 200 units were produced worldwide, because the NOS (new old stock) components it depends on are in short supply1.
The circuit and its transistor
At the heart of the Tesla MK III is the 104NU71, a germanium transistor of Soviet origin. It is an NPN, non-grounded type, which Keeley describes as designed to create some noise and offer classic Velcro fuzz, the gated, dying-battery character players associate with old germanium dirt boxes1.
The circuit is not a straight Tonebender clone. Keeley used design elements from the company's in-house pedals, including the Time Machine Boost and the Holy Fuzz1. Gearnews noted that the Tonebender style "could throw up problems in certain situations," a reference to the temperament germanium circuits are known for1.
Controls
The pedal, which Gearnews called a "Soviet Fuzz Bender," is controlled with three knobs1:
| Control | What it does |
|---|---|
| Fuzz | Sets the amount of fuzz |
| Tone | Shapes the treble content |
| Volume | Sets the output level |
Gearnews' reviewer took the simplicity as a point in the pedal's favor: "Since you cannot really get a bad sound out of such a simple circuit, this should be more than enough to dial in some decent fuzz tones"1.
Price and availability
The Tesla MK III carried a list price of $149 when announced, later raised to $1791. Each of the 200 pedals came with a T-shirt included, with a choice of design1. Because the run was capped by the supply of NOS transistors, the pedal is long gone from regular production; players looking at Keeley's current fuzz range will find later designs such as the Moon Fuzz, the Octa Psi Transfigurating Fuzz and the Suns Ultravoid Fuzz instead.
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Questions
How many Keeley Tesla MK III pedals were made?
Only 200 units were produced worldwide. Keeley limited the run because the pedal depends on a limited supply of NOS (new old stock) components, namely the Soviet-origin 104NU71 germanium transistor at the heart of the circuit. Once those transistors ran out, the run ended.
How much did the Keeley Tesla MK III cost?
The Tesla MK III carried a list price of $149 when it first appeared, which was later raised to $179. Both figures date from the pedal's 2017 announcement.
What transistor does the Keeley Tesla MK III use?
The pedal is built around the 104NU71, a germanium transistor of Soviet origin. It is an NOS (new old stock) part, and it is an NPN, non-grounded type. The limited supply of these transistors is why only 200 pedals were made.
Does the Keeley Tesla MK III come with a T-shirt?
Yes. Each pedal came with a T-shirt thrown in, with a choice of design. That made the limited run of 200 units as much a collector's package as a pedal purchase.
Is the Keeley Tesla MK III a Tonebender?
It is a fuzz in the style of a Tonebender, not a copy of one. Keeley built it around the Soviet 104NU71 germanium transistor and borrowed circuit design elements from the company's own Time Machine Boost and Holy Fuzz pedals.
Sources (1)
- Keeley Tesla MK III Soviet Fuzz Bender: A '70s-style Germanium dirtbox, gearnews.com, 2017-06-24
