There's no question that when driving the many ESL's that have impedances descending from high values at low frequencies to very low values at upper treble frequencies nearly all solid state amps will provide an increased emphasis of the upper treble in comparison to nearly all tube amps (assuming the amps being compared are operated within the limits of their voltage, current, power, and thermal capabilities).
Which of those two kinds of amplifier/speaker interactions results in the most correct acoustic output from the speaker is a separate question, however.
Regards,
-- Al
Which of those two kinds of amplifier/speaker interactions results in the most correct acoustic output from the speaker is a separate question, however.
Regards,
-- Al