Weird things with lm3886 (brainGT-kit)

I just finished (at least that's what I thought I did..) an lm3886 BrianGT kit, but when I powered up I measured some strange values.
First of all, the power supply board makes 28VDC from 22VAC. Not exactly the 1.4 factor I was expecting.
Next, when I measured the DC offset, it was huge: about 1.6V on one channel and 1.7V on the other and the chips get very hot after running for some minutes without any load.

Any advice?