You can reduce the output power of your Bugera 333XL or 160 Infinium amp should you wish to. This is useful if you want to get full saturation from the valves but at reduced volume. This is easily done with Bugera Infinium amps because the Infinium automatically biases the valves.   To reduce the wattage by half simply pull out (when the unit is powered off of course) 2 of the 4 power valves (these are the big valves just behind the grill on the back of the amp. Either pull the inner two valves or the outer two. Do not vary this config, only the inner two or outer two can be pulled out! 
  To keep the same load impedance on the two remaining tubes, the output load impedance should be doubled, say from 8 to 16 Ohms. Alternatively, if the same 8 Ohm load is still being used, the impedance selector might be set to 4 Ohm, which has the same effect to the primary side impedance, that is seen by the valves.