Another recent observation after listening more … at the exact same low listening levels (Benchmark LA4 volme set to -60dB), these particular Hypex class D power amp modules, seem to sound slightly leaner, compared to my Quad 909 … their bass seems less prominent, although still fairly tight and sound is very detailed. At higher volumes, differences aren’t as obvious though. Quad seem to have more ‘body’ at low volumes. Interesting.
Maybe it’s just an illusion, because Quad 909 voltage gain is 29.7 dB and it has input sensitivity of 0.775V, while these Hypex guys have gain around 25.5 dB and input sensitivity at 1.17V? So Quad would be expected to sound little louder, with exact same pre-amp volume knob position?
Well, that sounds about right, since when I add about +4 to +5dB on Benchmark LA4 pre-amp, then sound quality (even sound signature) becomes fairly comparable again (although still not exactly the same). Games never stop lol