Keeley Bubble Tron Flanger PhaserRobert Keeley and his crew are fans of Zappa. Rabid Fans. This pedal explores some of the famous, but very hard to find sounds of the past. Keeley Engineering has created another batch of Neo Vintage effects that never were. This time Keeley has made the Flanger and Phaser in dynamic with your pick attack and strength. Then add the Random Stepped Filter with the new M Style Synth bandpass shaping feature, and you have a lead guitarists dream tool.