McIntosh MC 601 Using two taps at the same Time


Has anyone use two taps at the same time 4ohms and 8ohms taps on a Mac amp? I usually use a biwire for my Vandersteen 2CE Sig II but I would like to separate the biwire as in, tap the lows on the 8ohms tap and tap the highs on the 4ohms tap to get a little more low end (bass). According to McIntosh, since Mac uses the autoformer, you can use two taps at the same time.
miketuason
I have MC501 mono's powering Vandersteen 3A signatures.I use two stereo pairs of speaker cables to bi-wire them.After trying all possible combinations.I use the 2 ohm taps for the lows,and the 4 ohm taps for the uppers.Sounds the best for me.I also utilized the same taps when I was using an internal bi-wire cable previously.As Mac states,using multiple taps is not an issue.
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?