The STM-1 is a low-cost quality microphone preamplifier designed for use in commercial sound and broadcast applications. The compact size makes it ideal where a larger or heavier preamp cannot be used. The high-performance circuit provides a fixed 50 dB gain to bring any mic-level signal up to the line-level range of nearly any line input. The STM-1 supply input is single ended and operates from 24 Vdc. Operation from 12 Vdc is possible with a 6 dB reduction in headroom. For intercom applications, the input will operate directly from a speaker.
| Input | 500 Ω balanced; 5 kΩ unbalanced |
|---|---|
| Phantom | 24Vdc; IEC 1938: 1996‑12, Filtered |
| Outputs (2) | +4 dBu 150 Ω balanced; ‑10dBv unbalanced |
| Frequency Response | 50 Hz to 20 kHz (+/‑ 1.5 dB) |
| Gain | 50 dB nominal |
| THD+N | < 0.05% |
| CMRR | > 60 dB (50 Hz to 30 kHz) |
| Residual Noise | < ‑70 dB (below +4 dBu; 150 Ω source @ 50 dB gain) |
| Headroom | > 20 dB (24 Vdc supply);> 14 dB (12 Vdc supply) |
| Phantom Power Input | 24 to 33 Vdc @ 10 mA maximum |
| Power Requirement | Ground‑Referenced, 24 to 33 Vdc @ 25 mA |
| Ambient Operating Environment | 0° C to 55° C |
| Weight | 0.145 lbs (0.66 kg) |
Usually arrives in 5-9 business days.
Usually arrives in 5-9 business days.
Usually arrives in 5-9 business days.
Usually arrives in 5-9 business days.
