1.9V core voltage on EP-MVP3G5

[Hanky]

I'm using my "old" K6-2+ together with the above mentioned board as a TV/DVD machine and in order to make the system even cooler (to make it less noisy as well) I thought about decreasing the CPU core voltage (the 500 MHz chip is already underclocked to 400 MHz). But the manual only says something about 1.8V, 2V and higher. As 1.8V could be not enough I would like to try 1.9V first. Anyone who knows how to enable it on this board or whether it's possible at all? (There are some voltages in the 2.xV area which are possible but not in the manual as well...)