@Vitaly2017
Have you decided on the ZX507 revisit?
I have been spending alot of time doing sound comparsion between:
No signal processing (safe mode, direct source mode on)
Very light signal processing (hi-res streaming off, direct source on)
Light signal processing (hi-res stream off, direct source off, DSP off)
Medium signal processing (hi-res stream off, DSEE HX AI on)
Heavy signal processing (hi-res stream On, Direct source off, dsp off)
Heaviest signal processing (hi-res streaming on, DSEE HX AI on)
I have done this comparsions using both my IER-M9 and 1AM2 all on balanced. Using a variety of music from DSD, Flac to AAC files.
In the end, I felt that the Heaviest Signal Processing won me over.
It is consistently more enjoyable across a variety of music. No signal processing places the importance on the recording quality of the source material to sound great. Heaviest signal processing is more forgiving and will sound great even with poorly mastered tracks.
Heaviest Signal Processing can flash out tiny details that you will otherwise miss in complex music passages as it presents the music in a 3D-like fashion which allows you to notice the background details that you will likely to miss in other processing modes.