I have a Taboo III UFO. My PDF manual states that the maximum speaker output is 4.6 watts:
 Quote:SPECIFICATIONS
"Single ended Class A Pentode
4.6 watts into 8 ohms
2.1 volts for full output .........."
 
However, the web page for the Taboo IV states that the output power is 2 watts (twice the 1000mv into an 8 ohm headphone load): 
Quote:HEADPHONE IMPEDANCE       POWER OUTPUT @ HEADPHONE JACK.
Figures double into loudspeakers.
4 ohms
      500 mw
8 ohms
      1000 mw 
This is a big difference. Which is the correct number into a nominal 8ohm speaker load?