Saviourwin,
I see nobody is chiming in for the Mc, so here are my 2 cents: I drive 3-way 90 dB speakers (vs yours at 89) with McIntosh MC275 and love it. The 275 is essentially the same amp section of the 2275 you listed. The 275 drives the speakers very nicely and to my ears without strain. You can certainly get more with more power than 75 Wpc, but then 75 Wpc is certainly more than 15! BTW, the 275 is said to actually deliver 90 Wpc, but I couldn't show proof of that claim.
I hope this helps...some.
I see nobody is chiming in for the Mc, so here are my 2 cents: I drive 3-way 90 dB speakers (vs yours at 89) with McIntosh MC275 and love it. The 275 is essentially the same amp section of the 2275 you listed. The 275 drives the speakers very nicely and to my ears without strain. You can certainly get more with more power than 75 Wpc, but then 75 Wpc is certainly more than 15! BTW, the 275 is said to actually deliver 90 Wpc, but I couldn't show proof of that claim.
I hope this helps...some.