> No, you get about 42V AC with a 60V DC offset.  There are other drawbacks
> too, but this idea is too rediculous to go any further with.
>   
What you can do is to use a H bridge. When one side pulls up the other 
pulls down. That way there is no DC offset and the peak voltage in both 
directions is the same as the DC voltage (so the peak-peak voltage is 
twice the DC voltage)

You can either use a plain squarewave or better use what is known of as 
a "modified sinewave". You drive positive for 1/4 cycle, then you don't 
drive at all for 1/4 cycle then you drive negative for 1/4 cycle than 
you don't drive at all for the remaining 1/4 cycle. That way you get the 
same peak/rms ratio as a sinewave without having the problems of an 
analog output stage.

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