Op-Amp Filters

The following op-amp filters were developed by Rick Andersen for the Theatre Organ. They should be direct replacements, but note: the LM358 op-amp requires a dual power supply. Pin 8 requires a voltage of approximately +10 to +15 volts, while pin 4 requires an equal but negative voltage of -10 to -15 volts.

Filter #4: Tuba Mirabilis 16'
Filter #10:  Oboe 8'
Filter #12: Brass Trumpet 8'
Filter #15: Tromba Clarion 4'

(More to come ... I hope)