I did not know was any benefit in zero Hertz response capable preamp, I thought DC Coupled was battery powered power supply to run out of the public AC electrical network.
With a Cherry Amp, listeners can remove a few stages of AC coupling in the system, but only with a DC coupled source (like the Cherry 130dB+ DAC DAC 2) can you have end-to-end DC coupling. Some DACs and DAC chips also have a option to apply a "software" AC couple (auto-zero or "offset cancellation"), which adds one or two poles of High Pass filtering, so in DAC designs, this must not be used to have true DC coupling from the digital domain all the way to the speaker.
Care must be taken to design the lowest offset possible at the source since it will be amplified by the amplifier's gain. Thanks for your comment.
