And why 1 megahertz? That supposedly doesn’t make any sense, because we don't hear so high. But the aim was also to have as less as possible phase shift in the audio band. And if you need to have less than one degree of phase shift in the frequency response extremes you need a bandwidth 50 times higher or lower. So 50 times 20 KIlohertz, is just 1 Megahertz. If you archive this, you can have a very low phase shift at 20 Kilohertz and also in the bass. I don't like DC coupling because it's dangerous to my opinion. So the amplifer is AC coupled, but with a very, very low cut-off frequency.

It's very easy to test an amplifier with a square wave, because with a square wave you can see the rise time in the highs and you can see the phase error in the lows if the plateau is flat. What's very funny is that nobody publishes anything about the bass response. Our amplifiers are quite flat up to 20 Hertz. Since the phase shift in the lower range is almost non-existent, you get the feeling that the power amplifier is going down an octave. If you connect a darTZeel amplifier to any speakers, the bass is more consistent, not louder, but more present.

You can read the second part of the interview with Hervé Delétraz here soon.