Hi I just noticed this thread
I added the PS1 a few months ago and I am extremely happy with this addition.
Everything that makes the K1X better than the K01xd and previous K1 is reinforced and multiplied .
The soundstage is way wider. Separation of instruments is much much more obvious as well as depth.
But its the impact and bass dynamics that absolutely shine.
Impact, immediacy and especially the bass are greatly improved,( not that they weren't stellar already).
The realism and impact are taken to another level altogether!
As you are probably aware of most high quality audio products, benefit dramatically as the power supply is upgraded from model to model .
This is no exception.
It takes it as close to the separates P1x and D1x as you can get.
Definitely an outstanding and very noticeable upgrade and improvement.
Hard to believe .....but very true.
I highly recommend it .