toshiba transistors and 1% tolerance parts on hte mmats.. MMats are some of the best amps ive used.. i have a pair of the orginal 1750 there good amps, there noisy if your not careful but there reliable and strong.. if you don't need 3kw and 2kw is enough go with the mmats..See if the RD is a V.1 ....if so get it....Zenon board....and that price is way too much IMO on the mmatts....also...what's your electrical consist of?