The dbx 933 is a module designed for use in the dbx F900, F900A, or FS900 powered mainframes, or in custom installations. It functions as a distribution amplifier (1-in/3-out) or a mixer (3-in/1-out), with individual channel muting and gain control. The module features patented dbx IC VCAs for level control, ensuring audio signals do not pass through front panel pots, and allows for external voltage control of levels.
| Frequency response | 20 Hz-20 kHz +0.5 dB |
|---|---|
| THD | 0.03% |
| IMD | 0.2% (SMPTE) |
| Equivalent input noise | ~87 dBv unweighted, -90 dBv A-wtd |
| Input impedance | 30 k-ohms balanced, 18.8 k-ohms unbalanced |
| Output impedance | 22 ohms |
| Channel mute | 60 dB |
| Power | 7 W |
| Dimensions | 5.25"h x 1.5"w x 9.5"d |
The module operates as a 1-channel-to-3-channel Distribution Amplifier or a 3-channel-to-1-channel Mixer.
You must move all 11 white jumpers on the PCB from the left position to the right position.
Change the three black jumpers on the PCB; set them to the top for balanced operation and the bottom for unbalanced operation.
The sensitivity is 50 mV per dB of change, where positive voltage produces attenuation and negative voltage produces gain.