MBD-1 / MOSFET BASS Distortion

MBD-1 / MOSFET BASS Distortion


Update: The next batch of MBDs is about 2 weeks away so I will be opening pre-orders for those who want to secure one early.

The Damnation Audio MOSFET Bass Distortion or “MBD-1” or simply “MBD” was originally intended as a distortion pedal for low-tuned high-output basses. I searched long and hard for a pedal that could get me the smooth distorted bass sounds I heard in other people’s rigs but without having to sacrifice my ape-like pick attack in Drop A# while pushing an unreasonably high output signal. I couldn’t find it so I had to build my own.

I then showed my friends who played normal basses in more rational tunings and they said, “that’s nice and all but it’s not dirty enough.” So, I added a boost on the front end to accommodate a large range of basses. Then I added a depth control to accommodate a large range of tunings. Then a parallel low-passed JFET boost channel was added to allow for blended distortion tones. The revisions kept going and the tweaking happened on and off for over a year and with multiple prototypes.

What started out as a simple project to help me raise hell on stage became a super flexible bass distortion capable of copping a ton of familiar and new bass distortion tones. This is the pedal that started Damnation Audio and it could be the only bass distortion you ever need. Well, that’s a pretty bold statement. How about I just say it’ll always be Good Enough.


Gain: Controls the amount of input gain of the distortion channel.

Level: Controls the output level of the distortion channel.

Tone: Tilt-style tone control for the distortion channel centered around 300Hz or 600Hz depending on position of “Shift” control.

Shift: Down position centers the “Tone” control at 300Hz with about a 10dB cut at the center frequency. Up position centers the “Tone” control at 600Hz with about a 6dB cut at the center frequency.

Clean: Controls output level of parallel low-passed JFET boost channel.

Depth: Controls the amount of low end injected into the distortion channel. Less depth for a brighter tone and more depth for a thicker tone.

Boost Trim: Internal trim pot (left hand side when looking at the PCB) which controls the amount of input gain to accommodate a wide range of basses. Boost range is from 3dB to 29dB of boost. Set at the factory at around 9 dB boost which works well with most basses.

Bias Trim: Internal trim pot (right hand side when looking at PCB) which controls the bias of the parallel JFET boost channel. Set at the factory at around 5V for the most amount of clean headroom.


Use only 9VDC 2.1mm center negative (boss-style) power adapters. Isolated pedal specific power supplies are highly recommended. Damnation Audio pedals are designed for maximum headroom and ideal performance with a 9V supply. Going above 9VDC will damage your pedal and void any warranties. Damnation Audio pedals do not accept 9V batteries.


In the interest of continuous improvement, all specifications are subject to change without notice.

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