McIntosh MX150 and Non-McIntosh amps

Another solution would be to buy two Schitt Vidar

One used as a monoblock amplifier ( XLR connection ) for the front speaker 400W rms
One used as stereo amplifer ( RCA connection ) for the surround
speakers . 100W rms

Obiviously , I should have wrote ´´ center ´´ speaker rather than 
´´ front ´´ speaker , with the XLR connection ( as a monoblock)

I forgot to write that the amplifier must have 4 ohms option .
all my speakers have 4 ohms impedance .

Then , forget about Schitt .

I have a Nord it has 3 separate amps, 3 separate power supplies, 1200/700 (?) they were the same as their One Up MB with rev D. buffer boards and Sparco 2590 Opamps with Sparco voltage regulators..  SERIOUS amp it will match your Mac SS no problem

NC500s, 500/700/550, 8/4/2 ohms, I'm close..

It has a 12 volt trigger I had added just for this.. It has 50 hours on it.  I went another direction.. It's actually 3 amps with 3 PS.. ONE Power Cord.. I have two good PC cables to pick from.. PM me.. AG can use the business..

They are 2 ohm stable, even 1 ohm, for short durations.. They are actually brand new, perfect factory as delivered to me. Setting in a Nord BOX...

BTW I been using Mac gear for 50 years this summer..  I use a C2500, MX120 and a C20, all 3 make the Nords sound fine. I use small planar line line arrays..