recommendation

@pharmacylaw 

"I also agree that although the 2270 is iconic, unless it has been significantly re-built, it is 40+ years old and prone to have failed components. I would take it out of your audio chain and stick with the MAC, exclusively. If the 2270 is only being used as a tuner, no offense, there are better vintage tuners out there. Having sold those receivers in the late 70's, the amp and preamp sections were the standout performers of the units. "

Amplifiers can oscillate which will take out a tweeter in short order and as @motown-l stated above your 2270 in old and probably unreliable, so you should either retire it or look in to having restored if its possible.

You should find out what caused this because you hook another pair of speakers, it could damage these too. Usually points to an amp issue or you played them too loud and you started clipping.

Also, nobody can give you advice on what to get until they know your room size, do you like analytical sound,  more bass, or neutral? 

OP, it's OK if you just want some trouble with your system to be an excuse to shop.  But what you are asking makes no sense - why and how did you connect a receiver to an integrated amp?

Typically if an entire speaker goes silent, one first looks to see if there is a fuse somewhere on that channel.  

Before you get out your credit card, let's understand what you did and trouble shoot it just a little bit.