Tvad, I don't think that spread would phase an MA-2 in the slightest, provided the quoted phase swing is not a problem (on which Ralph could opine) and the curve is not too abrupt and steep.
The technical description on the web site shows the minimum impedance is above 4 ohms. My Eidolons have a minimum impedance of 3.6 and the MA-2s match exceptionally well with those speakers. The Sound Labs have a much wider spread of impedance values than quoted for the Coincidence, and, with some limited exceptions where Sound Lab went crazy low in the impedance curve to better match to ss amps, the MA-2 amps have always worked well on them.
Keep in mind that the larger number of tubes in the MA-2 significantly lowers their output impedance compared to an MA-1, let alone an M-60. You are exactly correct that both of these A-S models require more careful matching. But, the MA-2 is far more tolerant and Ralph has told me that they can drive most speakers on the market provided the minimum impedance doesn't go below the mid-3 ohms range and provided there aren't crazy steep dips and rises in the curve.
Perhaps Ralph will weigh in here and help us.
.
The technical description on the web site shows the minimum impedance is above 4 ohms. My Eidolons have a minimum impedance of 3.6 and the MA-2s match exceptionally well with those speakers. The Sound Labs have a much wider spread of impedance values than quoted for the Coincidence, and, with some limited exceptions where Sound Lab went crazy low in the impedance curve to better match to ss amps, the MA-2 amps have always worked well on them.
Keep in mind that the larger number of tubes in the MA-2 significantly lowers their output impedance compared to an MA-1, let alone an M-60. You are exactly correct that both of these A-S models require more careful matching. But, the MA-2 is far more tolerant and Ralph has told me that they can drive most speakers on the market provided the minimum impedance doesn't go below the mid-3 ohms range and provided there aren't crazy steep dips and rises in the curve.
Perhaps Ralph will weigh in here and help us.
.