Here’s what MXR say about the Sub Octave Fuzz:

The Sub Octave Bass Fuzz dishes out thunderous low end with earth-shaking fuzz. To create this sonic behemoth, MXR’s engineers combined the Growl section of the Bass Octave Deluxe with a long-forgotten fuzz circuit. With three separate output level controls for the fuzz, sub octave, and dry signals, you can create your own recipe of subterranean tones without sacrificing any of your instrument’s natural sound. Further versatility comes in the form of the fuzz section’s tone controls and two switchable voices—warm and compressed or bright and aggressive—along with the Mid Level
control, which allows you to give your dry signal some more punch in the midrange.

• Combines two switchable fuzz flavors with a growling sub octave signal
• Separate Dry volume control ensures clean low end retention
• Bass and Treble controls allow you to fine-tune your fuzz signal
• Mid Level control allows you to boost your clean midrange to cut through the mix

  TRUE BYPASS: 0
  POWER SOURCE: PSU & Battery
  STEREO: 0
  BRAND: MXR
  DIGITAL/ANALOGUE: Analogue
  VOLTAGE: 9V