This good detail both circuit diagram ,PCB,part assembly,layout and show case in completed set that you can make with this information for 50 Watts Power Amplifier.
Could you read specification thus as below.
- Output Power 50 watts into 8Ω 70 watts into 4Ω
- Music Power 77 watts into 8Ω ;105 watts into 4Ω
- Frequency response -1dB at 14Hz and 70kHz (at 1W- see Fig.1)
- Input sensitivity 0.875V for 50Ω into 8Ω
- Harmonic distortion <.05% from 20Hz to 20kHz; typically <.003%
- Signal-to-Noise Ratio -114dB unweighted (22Hz to 22kHz); -119dB A-weighted, both with respect to 50W into 8Ω
- Damping factor >140dB at 100Hz & 1kHz, with respect to 8Ω and without PTC thermistor
- Protection fuses plus “Polyswitch” PTC thermistor .