I think you’ll find that both the 990 and the 950 have a peak output voltage that can exceed one volt, probably by a factor of about 10dB to 10 volts, or a little more, before clipping. I’ve never bothered to measure my 950’s absolute peak because I’ll never need it – I can’t get 10,000 watts per channel out of my 770 anyway.
Outlaw multi-channel amplifiers have a 28dB voltage gain as reported in the specs for the 770, 755 and 7100 models. One volt plus a 28dB voltage gain provides an output resulting in about 100 watts for a nominal eight-ohm load, while 1.43 volts with a 28dB voltage gain provides an output that results in about 200 watts into a nominal eight-ohm load. Therefore, a one volt input into any of these three amplifiers will result in approximately the same output of 100 watts into eight ohms. A 1.43 volt input would overdrive the 7100 while bringing the 755 and 770 to their full rated 200 watt output into eight ohms.
Seems to me this input sensitivity and gain level puts the Outlaw amps in the +4dB class, if one is concerned with such labels.