Why does my 35 watt tube amp draw 300 watts of power

Mapman, 
Well said and summarized. Choice is indeed a beautiful thing. 
Charles, 

The short answer to your question is "yes."

Tube amps are only 5% efficient.

We can easily see from the opening post of this thread that the above statement is false. If you can get two channels of 35 watts from 300 watts of wall power, clearly the amp must be more like 20% efficient, in this case 23.33% efficient, which falls within the norm for many tube amps.

Gents,
+1 to the cats that chimed in above, they have it exactly right. I have heard several Class D amps in my system and found them all dry and lifeless, although the newer variants appear to be better sounding. I heard a pair of Channel Island Class D mono-blocks amps paired with VSA speakers and they were splendid, vastly better than the Class D amps I have tried in my system.  I am currently using a 10wpc Dennis Had SET amp with my Spatial Audio Holograms and the sound is warm and luscious, but I admit I prefer the sound of tubes.  Power consumption and my electricity bill is neither here nor there in my decision to use tube amplification as it turns out to be a pittance either way.   Tube amplification sounds the best to my ears.       

More than likely it only draws 300 watts at full power output. Probably a lot less at idle and playing at moderate levels.