The MXR Custom Badass ’78 Distortion is a factory-modded, hot-rodded distortion pedal that delivers massive amp stack tone, old-school grit, and harmonically rich saturation. With its classic circuit pushed to the next level, this pedal produces soaring lead tones, punchy rhythms, and fully saturated drive reminiscent of cranked vintage tube amps.

The CRUNCH button introduces alternate diode/LED clipping to boost harmonic content and expand dynamic range, offering two distinct distortion voices in one compact unit. Whether in front of a clean amp or driving an already overdriven one, the ’78 Distortion delivers powerful, wide-open, amp-like response.

Powered by 9V battery or standard 9V DC supply. Built with high-quality components for a lifetime of tone.

• Factory-modded MXR distortion circuit
• Huge amp stack tones & vintage-inspired distortion
• CRUNCH switch for enhanced harmonics & dynamic clipping
• Delivers rich, saturated rhythms and soaring leads
• Amp-like response works with clean or driven amps
• High-performance internal components
• True hardwire bypass
• Powered by 9V battery or standard 9V DC adapter

• CRUNCH Button: Boosts harmonic content and dynamic range
• TONE: Adjusts overall brightness/darkness
• OUTPUT: Controls volume level
• DISTORTION: Adjusts amount of gain
• Footswitch: Engages effect (LED indicates ON)

• Connect guitar to INPUT and amp to OUTPUT.
• Set all knobs to 12 o’clock to start.
• Press footswitch to activate the pedal.
• Turn DISTORTION clockwise for more gain.
• Turn TONE clockwise for brighter sound.
• Turn OUTPUT to adjust volume.
• Engage CRUNCH for increased harmonic content.

• Input Impedance: 1 MΩ
• Output Impedance: 6 kΩ
• Nominal Input Level: -22 dBV
• Max Output Level: -5 dBV (Crunch Off), -2 dBV (Crunch On)
• Noise Floor: -84 dBV (A-weighted)
• Distortion Range: 27 dB at 500 Hz
• Max System Gain: 43 dB
• Tone Control: Tilt EQ ±4 dB at 100 Hz, ±5 dB at 2 kHz
• Bypass: True Hardwire
• Current Draw: 2.5 mA (LED off) / 6 mA (LED on)
• Power: 9V DC or 9V battery

• Model: MXR Custom Badass ’78 Distortion (M78)
• Power Options: 9V battery, Dunlop ECB003/ECB003E, DC Brick™, Iso-Brick™, Mini Iso-Brick™
• Recommended Genres: ’70s Hard Rock, ’80s Glam Metal, ’90s Alternative
• Build Quality: High-performance circuitry built for long-term use
  
• Manual: MXR Custom Badass '78 distortion
  

The MXR ’78 Distortion offers a powerful, responsive drive voice for players who want vintage amp attitude, modern reliability, and a versatile distortion platform capable of covering multiple eras of rock.