McIntosh MC 601 Using two taps at the same Time

Great question. I have a pair of MC2200 amps driving 2Cis bi-wired using two separate pairs of cables and it never crossed my mind to try the two different taps at the same time. For some reason I thought it could damage the amp(s). Learned something new and will definitely try it when I get home. Thanks for asking the question.

Just as a follow up, I didn’t get a chance to actually try the different connection options but found these comments in the MC2200 owners manual. Not sure if they apply to other Autoformer design McIntosh amps:
"If a load impedance is used that is lower than the output
impedance tap, then reduced power and possible distortion
will result. If a load impedance is used that is higher than
the output impedance tap, then neither the signal nor the
amplifier will be harmed but the power available is limited."
And this:
"DAMPING FACTOR:
STEREO
16 at 1 ohm output, 50 at 2 ohms output, 30 at 4 ohms output,
16 at 8 ohms output".

So it looks like the taps have different output impedance and the taps with higher damping factor should theoretically give a "tighter" bass, all things being equal. Assuming the same behavior between MC501 and the MC2200, this might explain why denman prefers the 2 ohm tap for the lows.

So to make it more simple, if you have an 8 ohms Speakers, you use the 8 ohms tap and if you have a 4 ohms Speakers, you use the 4 ohms tap and so on. Yes?

So to make it more simple, if you have an 8 ohms Speakers, you use the 8 ohms tap and if you have a 4 ohms Speakers, you use the 4 ohms tap and so on. Yes?

That's the idea but the fact is that an 8 ohm speaker has a varying impedance across the frequency spectrum so the outcome is not always predictable. When I tried the different taps - 2, 4, and 8 ohm, with my 2Cis - biwired to a single tap, I could hear an audible difference mostly in the size and shape of the soundstage with the 8 ohm giving the widest and deepest. l'll try the multi-tap scenario soon, just dragging my feet to cut/break the nicely soldered connections.