Hi in relation to your question above about line-out please see summery below:
1. There are common misunderstandings of hardware structure for Astell&Kern players - Basically there is no AMP or Volume control structure in AK H/W.
All A&K units (Including AK100 and AK120) do not use AMP or Volume control H/W. The volume is controlled by DAC chip itself.
Signal moves as below :
DAC(Volume is controlled here) -> LPF (Low Pass Filter / we call it as OPAMP) -> headphone Jack
Many people misunderstand this OPAMP and assume it’s for volume control and AMP feature, but actually it works only for turning and refining the sound.
Without knowledge of this, some mod companies bypass the signal from the DAC directly to line out jack but essentially this results in poor sound quality.
In pure technical terms, the headphone out is Line out hence the reason for not incorporating a separate line out Jack. The reason this option is set in the menu to max line out volume is to maximise the audio quality with better THD+N and crosstalk values for connection to a separate portable/desktop amps. Hence the reason for using an encoder switch on the side volume control wheel.
Thanks for your detailed answer.
- Please can you also tell us if there a possibility to have a balanced Line-Out to feed a balanced AMP ? And what is exactly the purpose of the strange "LO Block" if in fact, as you say, there is no need to have a separate LO ???
- Re your answer above, I have to say that I am not fully convinced: For many people here, including myself who did the Mod to my AK100, the Line out of a MODDED RWAK120-S sound much better through an External AMP than the original headphone-out (set to max volume) of a AK120 to an external AMP. So.... RWA must do something useful to change the Headphone out into a "clean real" line out ??
Here is what RWA says about his MOD: "...if you are referring to the RWAK100-S / 120-S, there is more being done than re-routing the output to bypass the head amp. The d/a's are changed to WM8741. They are configured to run in "hardware mode" (not software mode), so there is no longer volume control of the dac, period. The d/a's are configured to use their internal minimal phase filter option that the 8741 offers (not a linear phase filter, so there is no 'pre-ringing' of the output signal - so it sounds much more natural). In the case of the 120-B, a true balanced line-out is send to a new output jack (the SE out of the AK120-S also goes to a new jack). So there was more to it than just re-rounting to bypass the headphone output. "
so.... the question will become: Will the AK240 line out to an External AMP sound as good as the "RWA" line out of a MODDED RWAL120 ?
And, thanks in advance to A&K for taking the time to clarify thoses aspects here