A/DA FINAL PHASE

The ADA Final Phase was originally designed by Lee Powell in 1977. It used Vactec opto-coupled resistors and a very unique phase shift circuit along with a "one knob" distortion that keeps the level constant with different amounts of distortion. When David heard it, he was intrigued by the depth of the phasing. The original Final Phase design was shipped for only a few months and replaced with a more stable and manufacturable design using switched capacitors instead of the Vactecs in 1978. This preserved the "high-Q" sound of the phaser and broadened the sweep range.