Hey @mogelsvs,
V3 to V4 is a major architectural jump - Debian Buster to Bookworm, kernel upgrade to 6.12.x, updated MPD version, ALSA library changes, potentially different default buffer and resampling settings. Unlike the 4.072 to 4.073 comparison, there is actual technical substance here that could theoretically produce different behavior.
However, without verified identical playback settings between your V3 and V4 installations, logs showing MPD configuration from both, and level-matched blind A/B comparisons, we cannot isolate variables. This is subjective audiophile territory which is difficult to address with technical evidence alone. Perceived differences without controlled testing cannot be reliably attributed to software changes versus expectation bias.
If you want to dig deeper, provide logs and playback settings screenshots from both versions and we can compare configurations for actual measurable differences.
Alternatively you can remain on v3 if this is your preference:
Kind Regards,