The O Tone 40 is a compact solid-state combo built around a single-channel JFET design with a Class A/B power stage. It delivers 40 watts into a custom 12-inch Voice of the World speaker. The control layout is kept minimal: volume, treble, middle and bass, plus tremolo speed, tremolo depth and reverb.

Two onboard effects are included. The tremolo uses JFET circuitry and can be switched on and off with a footswitch. The reverb is digital and is voiced to imitate a spring tank without the hum. A fully buffered effects loop is provided so pedals keep their tone over long cable runs.

For quiet playing and recording, the headphone output is loaded with a cabinet simulation that emulates a miked 4x12 cabinet. The amp also has an Aux in and a Line out. It comes in orange or black basketweave vinyl, weighs 11.75 kg and measures 44 x 39.5 x 23 cm. A manual is available for download.