The top is a china A/BTop looks like a normal class d Korean bored with a decent xover. The other two are almost identical but I'd take the nvx. Of i where to guess it rated slightly higher than the other
They are all 4 channel. Top a/b other two class d. Top is fused for 105amps and is niceee quality. Other two are both fused for 75amps. The nvx and ppi make exact same power. The us is the strongest by far. All 3 would power mids/tweets without issue as thats why they were built to do.i assume this is for a sublooks like top is a/b 4ch
bottom 2 look similar, the nvx has 3 fuses bottom has 2 so i would assume the nvx is the most power
nvx is probably around 1000-1200
bottom is probably 800
nvx gets my vote unless you want to power vocals..... then 4 channel
do what. Guts tell u everything. Partr used. Very good idea on poten power output. If guality comps were used. Do u pick amp by brand sticker? Heatsink design? Color? Guts are all that matter. Bet u have opened every amp u have ever ran. Going from big a/b amps to d myselfThe bottom amp is a Precision Power P900.4. Second amp is NVX JAD800.4. P900.4 takes it for the highest power output, but 145W RMS @ 4 vs 100W RMS @ 4 isn't that big of a difference in SPL. The Barbara Ann will be less efficient and draw more current on average. If you want this to be about AB vs full range D then there is only one choice in this line-up if you want a Class AB amp.
I have no issues with Class D on everything and it's what I have run for years. Gut shots are not a valid reason to pick an amplifier in my opinion.