philkryder wrote:

Are there deterministic tests that tell when a device has a "good
enough" sine wave? Or is there some sort of accepted "spec"?

I've seen a 5% total harmonic distortion spec. How many steps is that?

What can we use to "know for sure" that the wave form of a device is
adequate BEFORE buying it?

Try it out? I got a local dealer to start up an EU2000 and run it with
and without a muffler.

Nick