The Ohmless Pedals AKC-4 is a Klon-style overdrive from Ohmless Pedals, a pedal builder based in Germany. It takes the Klon Centaur circuit as its starting point and adds what the original never had: four switchable clipping voices, a built-in boost that can be placed before or after the drive, a Blend control for mixing in dry signal, and MIDI switching. It is the maker's second take on the Klon, following the Ohmless Pedals Lorena Overdrive back in 20131.
A Klon-style overdrive with four clipping voices
Delicious Audio's Paolo De Gregorio calls the AKC-4 "the second attempt by German pedal builder Ohmless at perfecting the Klon Centaur circuit," adding Bass and Blend controls and a boost section to the familiar layout1. The four clipping voices give the pedal a range the single-voice original does not have: blue for a Ge Klon voicing, yellow for Schottky silicon, red for silicon, and aqua for MOSFET. Guitar Pedal X's Stefan Karlsson describes the design as "a wonderful Multi-Clipping All-Silicon design," RoHS compliant with no germanium components, with the blue Ge option presumably a Schottky diode3.
"this one does sound incredibly good - and gets overall amazingly close."
Karlsson also called it incredibly good value, a real find and a future cult pedal3. Delicious Audio notes the pedal earned the blessings of Eirik of The Living Room Demo1.
The pedal's list price has moved: Guitar Pedal X's 2023 buying guide listed it at $249 USD4, while the same reviewer's September 2025 Klon-klones roundup lists it at $187 USD3.
The controls and footswitches
The AKC-4 carries seven knobs and two footswitches3:
| Control | What it does |
|---|---|
| Level | Sets the overall output of the drive section (labeled Volume on the panel)1 |
| Gain | Sets the amount of gain from the drive section applied to your guitar signal1 |
| Blend | Mixes the effect signal (drive and boost) with the dry signal; full counterclockwise is 100% effect signal1 |
| Bass | Cuts or boosts low frequencies; at noon it gives the original Klon feel1 |
| Treble | Cuts or boosts high frequencies1 |
| Boost | Level for the boost section3 |
| Drive footswitch | On/off; hold to scroll through the clipping options3 |
| Boost footswitch | On/off; hold to change the boost order3 |
The clipping voices are selected by holding either footswitch, which changes its function from on/off to scrolling through the four options, or by MIDI1. The boost order options are yellow for pre overdrive and red for post overdrive4. Pedal of the Day notes the boost can be added pre or post overdrive to further shape your sound and stand out in the mix2.
MIDI covers the switching operations: overdrive on/off, clipping options 1 through 4, boost on/off, boost pre or post overdrive, deactivating the internal mute circuit, and the soft switches1. Pedal of the Day adds that the MIDI jack lets you turn the OD or boost on and off, select the clipping options, and shift the boost from pre to post drive2.
Power and bypass
The AKC-4 runs at 9V DC, center negative, and draws 190mA at 9V DC. It has no battery support, and the maker's warning is blunt: 18V will destroy your pedal1. At 190mA it needs its own adequate supply output rather than a low-current daisy-chain output. Bypass is true bypass using soft switches1.
Videos
Eirik Stordrange
Dennis Kayzer
Pedal of the Day
Questions
Does the Ohmless AKC-4 have germanium diodes?
No. Guitar Pedal X describes the AKC-4 as a multi-clipping all-silicon design that is RoHS compliant with no germanium components. The blue clipping voice is labeled Ge Klon, but Stefan Karlsson of Guitar Pedal X presumes that option is actually a Schottky diode rather than true germanium.
Can the AKC-4 boost go before or after the overdrive?
Yes. The boost section can be placed pre or post overdrive, and you can switch between the two orders by holding the boost footswitch or over MIDI. Pedal of the Day notes that the boost can be added before or after the drive to further shape your sound and stand out in the mix.
Does the Ohmless AKC-4 take a battery?
No. Delicious Audio's product page states the pedal has no battery support. It runs from a 9V DC center-negative supply, and the maker warns that 18V will destroy the pedal.
Is the Ohmless AKC-4 true bypass?
Yes. Pedal of the Day describes the AKC-4 as using soft switches and true bypass circuitry. The soft switches also do double duty: holding them changes their function from on/off to scrolling through the clipping options.
Where should the Bass knob be set for a stock Klon sound?
At noon. Delicious Audio's page explains that the Bass knob cuts or boosts low frequencies, and that if you want the original Klon feel, the knob needs to be at the noon position.
Sources (4)
- Ohmless Pedals AKC-4 Overdrive, Delicious Audio, 2022-12-26
- Ohmless Pedals AKC-4 Overdrive, Pedal of the Day, 2023-02-01
- Guitar Pedal X, Guitar Pedal X, 2025-09-03
- Guitar Pedal X, Guitar Pedal X, 2023-12-16
