S-99
| Brand | Heathkit |
| Manufacturer | Daystrom Ltd. |
| Function | Amplifier, Integrated (Kit) |
| Produced | 1963 |
| Country | United Kingdom |
| Signal Path | Analog Hardware |
| Dimensions | 34.5 × 12.1 × 31.8 cm (W × H × D) |
| Power | 100-125/200-250VAC, 50/60Hz 100W |
| Frequency Response | 30Hz-20kHz ±0.5dB |
| Output Power | 9W |
| THD (40Hz) | 0.42% |
| THD (1kHz) | 0.2% |
| THD (4kHz) | 0.35% |
| Input Sensitivity (Phono 1) | 4mV |
| Input Impedance (Phono 1) | 100kΩ |
| Input Sensitivity (Phono 2) | 180mV |
| Input Impedance (Phono 2) | 47kΩ |
| Input Sensitivity (Tuner) | 100mV |
| Input Impedance (Tuner) | 350kΩ |
| Input Sensitivity (Tape) | 100mV |
| Input Impedance (Tape) | 350kΩ |
| Finish | Two-tone Grey Perspex |
| MSRP (1966) | £28 9s 6d |
| Channels | 2 Channel |