I would like to clarify my initial post:
03-06-07: Tvad
Every improvement in audio has its genesis in power delivery. Better power delivery results in better sound.
First, I have heard the Prologue 2 at several demonstrations. I do not own one personally.
Second, my comments regarding power delivery (comprised of power supply, power conditioning, dedicated AC lines, and power cords) are made having experienced the benefits in my own system on several components including: Modwright Sony 999ES Signature Platinum, APL Philips SACD1000, APL Denon 3910, Electrocompaniet EMC 1-UP modified by Empirical Audio, Exemplar Denon 3910, Exemplar Denon 2900, VAC Phi 110, First Sound Presence Deluxe II, Modwright SWL9.0SE, Lamm LL2 Deluxe, Moscode 401HR.
Several of the components above were modified. The first area addressed in the modifications were the power supplies. Furthermore, I have experimented with a wide variety of power cords on each component. The price range of the power cords was $7 - $1500 retail. The differences I heard were not necessarily commensurate with the prices of the cords.
On each amplifier, for example, simply increasing the wire gauge to 9 awg from the stock power cords, which were typically 14 awg, made a significant difference in the size of the image, and in the natural, grain-free quality of the sound.
Why this is true, I cannot say. It's what I observed.
The question of the degree of significance of a power cord upgrade (or change) can only be determined by the individual listener, because some listeners observe benefits and others do not. There is no right or wrong, IMO.
I hope this helps to clear things up.