A-425B
| Brand | Altec, Altec Lansing |
| Manufacturer | Altec Lansing Corporation |
| Function | Amplifier, Microphone |
| Produced | 1949 |
| Country | United States |
| Model ID | A-425-B |
| Form Factor | 19" Rackmount |
| Signal Path | Analog Hardware |
| Dimensions | 25.7 × 6.9 × 0 cm (W × H × D) |
| Weight | 3.5lbs |
| Power | 6.3VAC 0.6A, 380VDC 5.5mA |
| Frequency Response | 20Hz-20kHz ±1dB (Normal Gain), 25Hz-15kHz ±1dB (High Gain) |
| Gain | 54dB |
| Gain (High) | 62dB |
| Power Output | 0.001W |
| Noise Level | -80dB |
| Input Impedance | 30/36Ω, 250/300Ω, 500/600Ω |
| Output Impedance | 20kΩ |
| Tube Complement | 6J7 (x2) |
| Finish | Blue-Gray |
| MSRP (1949) | $138 |
| Channels | 1 Channel |
| Notes | Requires P-505 Power Supply or equivalent |