Neptunium was a limited run pedal and has been permanently discontinued. I am leaving this page up only as a reference for those that purchased one and are looking for the information. Sushi Box has no plans to re-release Neptunium.

Neptunium is, as its name implies, based on the Nobelium preamp, which is in turn based on the incredible Noble preamp. The key feature of Nobelium is the XLR D.I. output, which only uses one tube, so I was asked if it would be possible to squeeze just that part into a much smaller enclosure. The result is Neptunium.

Neptunium is a great-sounding, simple to use tube preamp with a D.I. output for going straight to front of house or a recording interface. It features a two-band tonestack based on the classic Fender/Marshall/Vox tonestack. Both controls are boost-only, so a “flat” response is achieved with both controls all the way off.

One way in which Neptunium differs from the Noble preamp is in volume controls; the volume control on the face affects the 1/4″ output, but rather than make the XLR output a fixed level, a separate volume control affecting the XLR output was added to the side of the pedal next to the XLR jack above the ground lift switch.

Neptunium also features a switchable high-pass filter, which rolls off the lows at a rate of -6dB per octave below 90Hz, to tame the ultra low rumbles to prevent muddiness in a mix.

Neptunium takes a standard 9-12VDC center-negative power supply and steps up the voltage internally to run the 12AU7 tube at over 300V.

As a tube pedal, Neptunium requires a high amount of current to operate correctly. I recommend a 9-12VDC power supply capable of delivering at least 400mA. Using less than this can damage the power supply and/or the pedal.

Enclosure size: 4.8 in x 2.64 in x 1.58 in (122 mm x 67 mm x 39.6 mm)