904A
| Manufacturer | Moog |
| Function | Effect (low-pass VCF (24 dB-per-octave, considered the classic Moog filter)) |
| Produced | 1967 |
| Country | USA |
| Form Factor | Modular - 5U |
| Signal Path | Analog Hardware |
| Links | Modularsynthesis · Wikipedia |
| Notes | The 904-A is a voltage controlled low pass filter. It is pretty simple in operation and controls. This module has the separate edge finger PCB. The two PCBs are back-to-back making repairs difficult. This is an early version with a minimal number of trimmers. Resistor values do not match the earliest schematics dated July 25, 1967. |