Strip vs. purifier. On width, the PS106-DC eclipsed the PSM156 by a socket plus. With two 3m cords on hand—Puritan's UK wall plug was a sane 90° job which has the cord hug the wall rather than put a strained bow on it—I could quickly swap between both devices whilst leaving their wall connections untouched. In an upstairs system, the speakers were the overachieving 4-driver 3-way sound|kaos Vox 3f from Switzerland driven by the equally remarkable Bakoon AMP-13R. Source was a Soundaware D100Ref as SD card transport into a Jay's Audio DAC2-SE.
The key differentiator in this game of plug'n'play was simple dynamic range. With the PSM156 at the exact same volume of '33' on the Bakoon AMP-13R, tunes started even more quietly and peaked even higher. The upshot was more agitated ebb and flow, more emphatic expressivity.
Imagine a singer's lyrics written out as sung. You'd see certain letters enlarged, others put down with less pressure of pen to paper. With the PSM156, the difference between normal letters and capitals, between ornamental flourishes and contained penmanship, was a bit larger to show that a singer had laboured under greater emotional pressure.
In proper audio lingo, we'd call its cause an even lower noise floor. It's the proper term but applied in the negative. It doesn't explain how less is a benefit which becomes more. In this instance, I didn't observe audible detail with the costlier unit that was inaudible with the strip. I really only heard bigger ripples for higher dynamic contrast ratio. In this setup deep in the rural hinterlands, noise pollution on the utility spur was likely far less than it will be with an inner city flat. If here I'd pin on the PSM156 a performance value of 100—if you found something better, you'd lower that number—I'd call the PS106-DC a 90. From many years of experience with Spanish Vibex conditioners from Cliff Orman, I'd personally never order either Puritan without their DC filter option. The benefits of DC filtering for even source gear where small transformers barely if ever hum tends to be much underestimated. Because our top Vibex is a two-piece job where one plugs into the other, I've experimented with DC+AC vs just DC filtering. In multiple homes already, I concluded that properly executed, DC filtering was the audibly even more relevant. In the context of the PS106-DC/PSM156 comparison, the most important takeaway for the more cash-strapped shopper is clearly that the less than half-priced strip already provides the lion's share of benefits of their range topper.