![File:Dan Armstrong Green Ringer circuit - an octave-up effect with a ring-modulator touch to it - just finished building (2006-03-05 22.51.45 by germanium).jpg - Wikimedia Commons File:Dan Armstrong Green Ringer circuit - an octave-up effect with a ring-modulator touch to it - just finished building (2006-03-05 22.51.45 by germanium).jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Dan_Armstrong_Green_Ringer_circuit_-_an_octave-up_effect_with_a_ring-modulator_touch_to_it_-_just_finished_building_%282006-03-05_22.51.45_by_germanium%29.jpg/640px-Dan_Armstrong_Green_Ringer_circuit_-_an_octave-up_effect_with_a_ring-modulator_touch_to_it_-_just_finished_building_%282006-03-05_22.51.45_by_germanium%29.jpg)
File:Dan Armstrong Green Ringer circuit - an octave-up effect with a ring-modulator touch to it - just finished building (2006-03-05 22.51.45 by germanium).jpg - Wikimedia Commons
Fuzzlord Nazareth Pedal (Proco Rat Style / Octave / Green Ringer) in Pankow - Prenzlauer Berg | Musikinstrumente und Zubehör gebraucht kaufen | eBay Kleinanzeigen
![File:Atmos - Green-Ringer-based octaver with extra LED clipping (2007-02-05 21.45.11 by germanium).gif - Wikimedia Commons File:Atmos - Green-Ringer-based octaver with extra LED clipping (2007-02-05 21.45.11 by germanium).gif - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/7/77/Atmos_-_Green-Ringer-based_octaver_with_extra_LED_clipping_%282007-02-05_21.45.11_by_germanium%29.gif)