If you are still concerned after the above posts. The amp may work great as in Smp's experience. Twl has a point too. you may not get optimum performance into a load like that. Take a page from the Magnepan and elecrostat guys and look into this link.
http://www.zeroimpedance.com/products.html
My uderstanding is, that many tube amps will work and sound best out of a particular tap. The ARC amp I have, due to the design, seems to work best from the 8 ohm tap,just as an example. The Zero can make the amp see the impedance you need. It's worth looking at.