I own both of these receivers. The MAC is 40W/ch. and the Sansui I do believe is 47W/ch. I've owend the MAC for 15 years now, but I've only owned the Sansui for a week. I've been doing a back and forth since last night to notice the differences. I have them playing through a SONY 3AXES CD Player and Klipsch KLF-20s. The MAC sounds warmer, has better low end and solid mids and highs. The Sansui has decent punch, but has brighter mids and highs. I have to turn the Bass on the Sui to +6 to match the MAC zeroed out. I'd have to say the build quality goes to the MAC, but the Sansui's aluminum machining is just as nice or better. I like the MAC's Walnut case better though, the Sui's almost looks like vinyl, but it's not.
The MAC has always made me happy with the sound it produces. I use to live in a house with a 17'x23'x9' Livingroom that had plaster walls, hard wood floors and coved ceilings....MY GOD did the MAC sound HUGE in that room...I couldn't help but to turn it up every chance I got.
I was surprised by the Sansui when I first hooked it to my Klipsch. It does have some Mmmph! I've played all types of music through it. I've put the spurs to it a few times with some Sabbath and Zeppelin...it sounded GREAT! Things that impressed me with the Sui are the number of inputs...the ass end looks ike a modern receiver. Six speaker outputs also...very nice. The weight of the thing...definitely SOLID! MINTY and all for only $70.