A 37 watt output at 8 ohms is a rail voltage of 17.2 volts RMS. The peak power is based on the RMS voltage x 1.414, which is 24.3 volts. Power is therefore 24.3 squared divided by 8, or 74 watts.
That’s why the spec says "> 70 watts". The 1.5 Vrms will give peak power.
That’s why the spec says "> 70 watts". The 1.5 Vrms will give peak power.