I had thought one preamp was the same as another so far as driving multiple main amps went. But I recently read that driving into the line level crossover components is more difficult for some amps than for others. Unfortunately the article did not elaborate.
     Does someone here know what the author would have been referring to? Is it a question of voltage gain, or damping factor, or output impedance, or what would it be that causes the line level crossover to overwhelm some preamps and not others?