CA3080 4 Stages Phaser
I just love Electro-Harmonix phasers such as the Small Stone or the Electric Mistress..
I found these schematics to build a Small Stone replica using the CA3080 Operational Transconductance Amplifiers:
The build on a breadboard looks like this:
And the sound is great, here’s a demo using a great song by Adrian Nation, Five Fingers Rapid: