Korg OD-S

The Korg OD-S is a build-it-yourself overdrive pedal kit from Korg, shown at NAMM in January 2020 and reported for release that February¹². What sets it apart from most DIY pedal kits is its gain stage: instead of clipping diodes or an op-amp, the circuit is built around Korg's Nutube 6P1, a fully analog triode vacuum tube that Korg says delivers "a warm sound and rich harmonic response"³⁴. The whole pedal is assembled by hand with no soldering, which Korg pitches as the fun of DIY without the iron⁴.

Korg's Nu:Tekt range already included an easy-to-build synth, the NTS-1, before the OD-S arrived¹. Guitar World's reviewer found the build itself half the appeal: "Easy to assemble (no soldering!), and satisfying too."⁵

Building it: no soldering, about 45 minutes

The OD-S is a kit you put together yourself, and the selling point Korg leads with is that no soldering is required⁴. Instead, the parts are secured with basic hand tools.

• A screwdriver and a socket set are needed; a soldering iron is not⁵
• Assembly takes 45 minutes at most, per Guitar World's reviewer⁵
• MusicRadar's review team agrees: "All in, the assembly will take you 45 minutes and you won't need to take the soldering iron out of the toolbox."⁶
• Korg also lets you customize the pedal as you build it⁴

The kit also gives you a choice between two different types of overdrive when assembling it, so the build decision shapes the finished sound, not just the cosmetics².

The Nutube: a real vacuum tube, miniaturized

The Nutube 6P1 in the OD-S is a genuine vacuum tube, not a solid-state emulation. Korg describes it as "a new and revolutionary fully analog triode vacuum tube developed by KORG INC. and Noritake Itron Corporation"⁴³. It works by putting vacuum fluorescent display technology to practical use as an audio tube, which is what allows it to be far smaller than a conventional bottle⁷.

For a player, the practical differences matter:

• A Nutube draws far less power than a traditional vacuum tube, which is why the OD-S can run on a single 9V battery⁸
• It is reported to have a lifespan of 30,000 hours⁸
• It is described as much smaller than original tubes and with a much longer life⁹

The NuTube in the OD-S is a fully analog triode vacuum tube, which Korg says delivers a warm sound and rich harmonic response in a compact pedal⁴. The GAIN knob adjusts the input level to that vacuum tube, setting how hard the tube is driven⁴.

Controls and sound

The control set is minimal. A GAIN knob adjusts the input level to the vacuum tube⁴, and the kit's two overdrive types are chosen during the build⁴². Korg says the fully analog triode circuit is what gives the pedal its warmth and harmonic content⁴.

What the pedal actually sounds like is a matter for the reviewers, and both major reviews landed positively. MusicRadar's overall verdict⁵⁶:

Guitar World's reviewer likewise found the assembly easy and satisfying⁵.

Powering it

The OD-S runs two ways, and both are spelled out in Korg's specifications³.

Current draw is 46mA³. The battery life is a direct benefit of the Nutube's low power consumption compared with a traditional tube⁸.

Bypass and live use

The OD-S uses true bypass, which Korg says makes it "an ideal pedal for live performances" because the unaffected signal path stays clean when the pedal is off⁴. Both Guitar World and MusicRadar confirm true bypass in their spec listings⁵⁶.

The BK version: the same pedal, pre-built

The OD-S series later gained a second version. The Korg OD-S BK ships fully assembled from the factory as a no-assembly model, where the original OD-S was the build-it-yourself kit¹⁰. The BK keeps the Nutube circuit, true bypass, and battery operation, and adds a switch that toggles between single and double Nutube stages so you can hear the tonal difference between one and two tube stages¹⁰. Korg's Japanese page describes it as delivering realistic vacuum tube sound in a pedal that runs on battery¹⁰.

Videos

Click to load

Click to load

Click to load

Questions