The Joyo Nebulous packs a big phase punch for a little yellow pedal. Some phasers like the old MXR ones only had one control - speed. The Nebulous adds Depth and Feedback to nail that tone you want. And it's all analogue, no digital sharpness here. Just warm watery classic tones at a price and size you can't argue with. The nebulous phaser splits the audio signal into 2 separate paths. One is unaffected while the other passes through 4 all pass filters and a LFO (Low Frequency Oscillator), these two signals are then mixed back together. As the Nebulous has 4 of these all pass filter it makes it a 4 stage phaser.