The Spontaneous Audio Devices Son of Kong is a two-channel EQ and distortion pedal, an evolution of the original Kong circuit that Arthur "Midget" Sloatman built for Frank Zappa's guitars. Premier Guitar describes it as carrying "the original Zappa-approved EQ circuit" in "a much more pedalboard-friendly enclosure"1.
Where it came from
Zappa's guitars were fitted with Sloatman's custom EQ and gain circuitry, which gave Frank complete on-board control over his sound. The Son of Kong takes that original circuit and repackages it as a stompbox. Sloatman's name is attached to the design, and Spontaneous Audio Devices builds it1.
Zappa's wider rig is well documented elsewhere: Guitar World's history of his effects notes the dbx 160 Compressor/Limiter he was using in his guitar rig along with pedals, a rig remembered by Chris Buono, Rod Brakes, Dweezil Zappa and Eilon Paz2. If you are exploring this territory, the Son of Kong sits closest to preamp pedals and EQ pedals as much as to distortion pedals.
The controls
The Son of Kong is built around two channels, each with its own volume control, plus a shared EQ section1:
| Control | What it does |
|---|---|
| Right footswitch | Toggles between the two channels, each with independent volume controls1 |
| G knob | Controls the gain level for a given channel1 |
| F knob | Boosts frequencies anywhere from 35 Hz to 5 kHz1 |
| EQ switch | Switches the EQ in and out of the second channel's circuit, from a switch beneath that channel's volume knob1 |
| Boost switch | Located between the volume controls, boosts the volume by 20dB1 |
The two channels are not matched for level. The first channel has a maximum 15dB volume boost, while the second one cranks out 35dB of boost1. That spread means the second channel can act as a serious lift for solos, and the 20dB switch between the volume controls adds another layer of level on top.
Build, power and outputs
Premier Guitar's reviewer described the hardware as "a sturdy, bent-steel chassis and hand-wired circuit," concluding that "the Son of Kong is as tough as its name suggests"1. The hand-wired construction and steel enclosure put it in the camp of pedals built to be opened and serviced rather than replaced.
Power is worth planning for. The pedal accepts power sources up to 40V, which the reviewer notes is for increased headroom1. Because that ceiling is higher than many pedals ask for, it is worth knowing what your power supply delivers before slotting it in.
The Son of Kong accepts power sources up to 40V for increased headroom1. The headroom the design allows depends on the supply you run it from, so match the supply to what the pedal accepts.
The other standout feature is the direct XLR DI output jack, which lets you run directly into a mixing console or PA1. For a player who records or plays venues without miking an amp, that means the pedal's EQ and gain character can reach the desk on its own terms.
What reviewers said
Premier Guitar's 2023 review is the published verdict on record. The reviewer found that with a Stratocaster and a Twin Reverb, the effect is like playing through a clean JFET-style booster with the EQ knobs at noon and volume at unity1. On build quality, the one-word verdict was: "Rock-solid."1
Videos
Pete Thorn
SpontaneousAudio
SpontaneousAudio
Questions
Who designed the Spontaneous Audio Devices Son of Kong?
The Son of Kong was designed by Arthur "Midget" Sloatman, and it is made by Spontaneous Audio Devices. Premier Guitar describes it as an evolution of the original Kong circuit Sloatman built for Frank Zappa's guitars, reworked into a more pedalboard-friendly enclosure with the original Zappa-approved EQ circuit on board.
What is the Kong circuit Frank Zappa used?
The Kong was custom EQ and gain circuitry that Arthur Sloatman built to be fitted to Frank Zappa's guitars, giving Zappa complete on-board control over his tone. The Son of Kong is an evolution of that original circuit, packaged as a two-channel pedal rather than on-board guitar electronics.
Does the Son of Kong have a DI output?
Yes. Alongside its standard output, the Son of Kong has a direct XLR DI output jack that lets you run straight into a mixing console or PA, which is unusual for a distortion and EQ pedal and useful for recording or playing through a backline-less setup.
What frequency range does the Son of Kong EQ cover?
The F knob boosts frequencies anywhere from 35 Hz to 5 kHz, so it reaches from low bass fundamentals well into the presence range of a guitar signal. The EQ can be switched in and out of the second channel's circuit from a switch beneath that channel's volume knob.
How much does the Son of Kong cost?
Premier Guitar's June 2023 review lists the Son of Kong at $495 USD.
Sources (2)
- Spontaneous Audio Devices Son of Kong Review, Premier Guitar, 2013-09-28
- The story of Frank Zappa and the Mu-Tron Bi-Phase, Guitar World, 2021-04-28