Posted by
Jun 22, 2021

Electrofoods RBMK

For those born too late to know or remember, RBMK was the name of the (lovely) model of nuclear reactor that melted in Chernobyl that day in 1986. If you wanted to find just a word to described it, probably “unstable” would be it.

Electrofoods Ultd.‘s RBMK is a boost/overdrive/distortion with interactive EQ, gain, and stability controls, born out of a brainstorming session between Matt and Carl of Electrofoods and Evan Craig of Dirge Electronic, triggered by a conversation about the custom discrete opamp the duo created especially for their Nepenthes distortion.

With an internal voltage running at up to 24VDC, this is a pedal that can extremely loud, although at lower Volume and Gain setting it will sound clean.

Needless to say, the fun begins when the bizarrely named controls are tweaked, and the gain and volume knobs turned up (Depth controls the amount of low-end sent to the op-amp stage):

The Shielding knob is the aforementioned “stability control.” Here’s how the manufacturer describes what it does:

T his control is haranguing the discrete opamp circuit in multiple ways at the same time. [..] At higher settings it may just tweak the distortion tone by sneaking in some extra harmonics, but at lower settings things are likely to start going bananas.

The Void Coefficient toggle is also a weird one:

[It] changes the range of the Shielding knob, which will also change the character of the eventual oscillation AND how that oscillation might react to your playing. “-” is the most stable, “+” is a bit less stable, and the unlabeled mystery of the middle position is, of course, the least stable.

(Nerds are invited to Google RBMK Void Coefficient.)

Check out the video of the Electrofoods Ultd. + Dirge Electronics RBMK!

Once upon a time, our friend and yours Evan Craig, the delightfully maniacal possible-fae behind Dirge Electronics, whispered a series of pretty little twisted ideas into our ears for things that one could, if so mischievously inclined, do with the discrete opamp we created especially for the Nepenthes. By that afternoon we were trading concepts, schematics, and gleeful cackles back and forth in excitement. The end result is an obsessively tweakable boost/overdrive/distortion with interactive EQ, gain, and stability controls, named for the inherently unstable reactor design used in the Chernobyl nuclear power plant. The RBMK can be completely friendly when you want it to be (the so-called Atoms for Peace ideal), but let it off the reigns and it may bombard your tone with alpha particles, sing its own fissile tunes in the spaces between your playing, or blast off the Upper Biological Shield and become a total irradiated glitch machine.

CONTROLS

Level: Volume knob. BUT! This sucker is loud! This pedal can run at 18VDC & even 24VDC, if you’re so inclined, at which point it will be ridiculously effing loud (or more likely just drive whatever comes next into severe distortion!).

Shielding: This is the main stability control. More Shielding equals more stability. At higher settings it may just tweak the distortion tone by sneaking in some extra harmonics, but at lower settings things are likely to start going bananas. Also, this control is haranguing the discrete opamp circuit in multiple ways at the same time, all of which may reduce the output volume slightly (it’ll still be deafening at max volume though, promise!), so don’t be afraid to tweak the Level knob after messing with the Shielding control.

Gain: At low Gain settings, the output can be 100% clean. At higher settings you can hear the discrete opamp’s naturally musical distortion with no clipping diodes or other gain stages getting in the way. But beware! The higher the Gain setting, the easier the RBMK slips into instability.

Depth: Adjusts how much low end hits the discrete opamp stage, and therefore can significantly affect the character of the distortion. However, nuke reactors are complex beasts! Lower Depth settings are ALSO more unstable.

Void Coefficient: Ok, this is a weird one. It kind of changes the range of the Shielding knob, which will also change the character of the eventual oscillation AND how that oscillation might react to your playing. “-” is the most stable, “+” is a bit less stable, and the unlabeled mystery of the middle position is, of course, the least stable.

P.S. Look up RBMK Void Coefficient if you reeeally want to nerd out.