Ok here's my take on software enhanced sound and purist approach to audio:
I used to be purist. I got myself a R2R Audio-GD Master 7 and run it on Non-Oversampling Mode and bypass any filtering.
Customizable DSP on the audio-gd
http://www.audio-gd.com/Master/Master-7/M7EN_Use.htm
Yes the master 7 on NOS did sound good on soundstage but it is very jitter sensitive and you needed a really really good source to make it sound focused. NOS isn't perfect as transients sounded weak and 8x oversampling on the DSP is a trade off as the filtering isn't that good as the soundstage feels collapsed. You either had to pick a laid back NOS sound or a sharper sounding(transients) 8x oversampling with small soundstage.
But once I listen to Schitt Yggdrasil DAC, I realised that it's the DSP algorithms and filtering that makes the difference in the sound. It strikes a perfect balance between good soundstage and sharp transients. It is really a good R2R DAC that does PCM well as it is limited to 24bit 192KHz, no MQA or DSD.
Then comes to the Sony. On the zx2 you can also enable a mode that sounds like non-oversampling dac by disabling the sound adjustment app. It made things sound warm but it also make transients doesn't sound as sharp in comparison to sound adjustment app turned on and also DSEE HX turned on. With DSEE HX turned on, it sounded closer to Schitt Yggdrasil transient delivery but it also destroyed the soundstaging. I felt that the ZX300 DSEE HX also suffered from this soundstage collapsed issue.
When you attend a concert in real life, depending on your sitting position, the drums and cymbals transients really hits sharply and feels stronger than what you experience with playback of live recordings.(especially on portable daps and iems)
During concert recording, there are multiple microphones that capture the singer, the audience and the multiple instruments. What you are hearing from concert recording usually is already re-mastered/recreated by a sound engineer. Not to mention that the Analog to Digital Converters and equipment used record already has filtering algorithms and input compression(which affects dynamics/transients) to prevent overloading of the microphones. What I meant to say is that there isn't such a thing as audio purist as everything that is recorded digitally has been affected one way or another by limitations of microphone or analog processing and studio remastering.
What Sony has done is that they have ran simulation models between what is lost during the conversion from their studio master DSD/DXD files and the end result consumer PCM / AAC format that we usually listen to. Then they came out with this DSEE HX algorithm that can restore the audio back to near studio master quality.
This doesn't even take into account that our headphones and IEMs all have issues with soundstaging and freqency coherency, phase timing issues from the placement of the drivers and the use of crossover networks etc..
What I felt about the ZX507 DSEE HX AI is that it can deliver a sound closest to what you experience when you attend a concert in real life. Both transients and soundstaging feels just right on my IER-M9. I now take the approach that whatever sounds better to my ears is more important than having a purist approach as there isn't really a true purist approach in digital audio as you are already dealing with some kind of digital filtering and digital jitters in the first place.
