Stock, the PS1 is really nothing special and has some serious flaws with regard to audio. The output stage causes treble roll-off, sounds relatively shit and needs to be bypassed. I followed http://dogbreath.de/ and used cat5 wire. I also replaced some power supply caps.

The SMPS is also a big problem, as it WILL add a haze to the sound and generate considerable amounts of noise. It's also worryingly close to the CD transport, so does need to be put into an external box. When I've got the time, I'll add a linear regulated supply to mine.

When looking at the PS1's circuitry and attention to grounding (it's actually pretty well built), at the heart of it is a transport designed for low jitter performance for 32bit 3D games, so the clock distribution circuit is way overkill and is something not seen on regular CDPs. The timing of this player is ridiculous, with an obvious flaw with mine in regard to bass depth and weight.

There is a consensus that it's the transport side of things that gives the PS1 good sound, not the DAC per se. I do think there's a reason these players have found their way into a variety of high end setups, have a big following in Germany and are popular with DIYers.

Different horses for different courses I guess. I'd be happy to send mine onto someone after I've fitted an outboard power supply.