| Model ID | Williamson Type Amplifier W3-AM, W-3A |
| Signal Path | Analog Hardware |
| Dimensions | 14 × 17.8 × 27.9 cm (W × H × D); 14 × 17.8 × 27.9 cm (W × H × D) |
| Weight | 29lbs (Shipped) |
| Power | 105-125VAC, 50/60Hz 120W |
| Frequency Response | 20Hz-80kHz ±1.5dB (1W), 20Hz-20kHz ±0.5dB (20W) |
| Output Power | 20W |
| Peak Output | 36W |
| THD (20W) | 1% |
| IMD (20W) | 1.2% |
| Impedance Load | 4/8/16Ω |
| SNR (20W) | 85.3dB |
| Feedback Factor | 18dB |
| Damping Factor | 14 |
| Output Tube | 5881 |
| Tube Complement | 6SN7GT (x2), 5881 (x2), 5V4G |
| Output Transformer | Acrosound TO-300 |
| MSRP (1957) | $49.75 |
| Channels | 1 Channel |
