Korg HG-S (HIGH GAIN OD)

The Korg HG-S, which Korg markets as the HIGH GAIN OD, is a high-gain overdrive pedal built around a vacuum tube circuit¹. It sits in Korg's range of tube-based overdrive products alongside kits like the Korg Nu:Tekt OD-S and the Korg OD-KIT, and it belongs to the wider family of overdrive pedals that push a signal into distortion.

What it does

The HG-S produces high-gain overdrive, the saturated, compressed distortion territory that players usually reach for hard rock and heavy styles, by passing the signal through a vacuum tube stage¹.

Its character is shaped by two gain controls, and the distinction between them is the interesting part of the design¹:

• GAIN adjusts the input level going into the tube, that is, how hard the tube is driven¹.
• TUBE GAIN changes the distortion by altering the anode load of the tube circuit, a different point in the circuit from the input drive¹.

Korg describes the intent of the pair this way: "真空管の音色を好みに合わせて調整することが可能です" (the tone of the tube can be adjusted to the player's taste)¹. In practice, having a drive control and a circuit-load control means the amount of distortion and the way the tube distorts can be set separately, rather than one knob doing both jobs.