Cooch: You wrote, "altho, on my reference system i do not get the boominess. that is what puzzles me." I don't know what your reference system is but may well be that the speakers in your reference system synergize better with an amp with low damping factor. Could very well be that the speakers in your reference system are damped in the woofer already (Merlins do this, for example and pair better with low damped amps). The use of little feedback in your amp indicates a low damping factor. Tvad recommended using the Maggies on the 8 ohm taps as this is known as "light loading" and will increase the damping. You may consider calling Magnepan and see what they advise about "light loading". If they tell you "no, don't do it", then don't. The autoformers will transform the impedance allowing you to use the 8 ohm taps and acheive higher damping. In my experience with Maggies, they respond better to amps with high damping factors (as always, there are exceptions). I don't think the break in time with your amp is going to cure the boomy bass; I truly think the boomy bass is directly related to the use of little feedback on the amp. I'd first call Magnepan to see if you can try "light loading". If Magnepan says "no", call Paul Speltz to see if he still offers the trial period with the Zeros. Short of these steps, I cannot think of any other solution other than a different amp. Good luck.
