The P90SD needs quite a lot of burn in, mainly due to the 1000uF capacitance on the output which needs to stabilize, without burn in it sounds hazy and bloated with sharp mids.
Also interestingly, I found out that the P90SD uses some higher quality parts than H01, even though it is a smaller scale of circuit. Like P90SD has polymer capacitors, and thin film capacitors, while the H01 uses cheaper types of electrolytics. The P90SD also has a Dual Core Blackfin BF606 CPU which probably has some kind of advantages, this CPU alone costs $40, so it's actually the most expensive CPU in any dap at the moment
, the Paw Gold uses the cheaper single core Blackfin, I don't know what difference the cpu makes but it's cool to know lol. I love bragging about random stuff like this haha.