The Hellraiser is an analog pedal from Cog Effects that combines fuzz, distortion, an octaver and a filter in one box. Rather than running those circuits in series, the pedal puts a Grand Tarkin Bass Fuzz, a Knightfall Distortion and a T-65 Octave all in parallel, so their outputs are blended together rather than stacked. Cog Effects describes it as "very much an expansion on the concept of the T-65 Octave and parallel sub octave in general."1
What it does
Because the three circuits run in parallel, the Hellraiser is built around blending rather than gain staging. The pedal has four level controls for mixing the dry signal, with only one ever active depending on which combination of effects is selected. That means the pedal decides which dry level control is in play as you switch fuzz, distortion and octave in and out, keeping the clean part of your signal at a set level for each combination.1
The pedal covers four effect types at once: fuzz, distortion, octaver and filter.1 For context on the effect types involved, see Fuzz Pedals, Distortion Pedals, Octave & Pitch Pedals and Filter Pedals.
Where it came from: the T-65 Octave
The Hellraiser's parallel sub octave approach traces back to the T-65 Octave, which Cog Effects launched in 2016. The T-65 kept the control set of the original design, with level controls for the clean signal, octave down, octave up and a parallel effects loop. Cog Effects' Tom George said "The parallel effects loop allows you to mix in any effects with your octave and clean signals to create new sounds."2
gearnews.com's Jef described the T-65 as "basically an 'upgraded' version of the old design that allows you to blend in other effects via the built-in" parallel loop.3
The Hellraiser takes that idea further: instead of an external loop for blending other pedals, it builds the fuzz, distortion and octave circuits into the same box and runs them in parallel internally.1
Power
The Hellraiser runs on mains operation, per the maker's listing.1
Sources (3)
- Hellraiser by Cog Effects, RockBoard PedalPedia, 2026
- Cog Effects Launches Line Of Analog Octave Pedals, Premier Guitar, 2016-08-22
- Cog Effects aim to get down and dirty with T-65,T-47 and T-70 octaves, gearnews.com, 2016-08-23


