I asked Puritan and they answered- company secerets- but essentially indicated that yes- impedance is raised by the PSM156. I thought one of you technical people could measure this and that is why I asked. Sorry to offend you all.
Regarding relevance, EVERYONE in the power conditioning industry AGREES that increased impedance harms sound. The only question is if removal of EMI and other benifits outweigh the negitive....
Here is a copy of Mikes letter:
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Hi Steven,
The only truly relevant measurement is with the instruments each side of your head.
We do not publish detailed blueprints of measurements, materials, methods or other design aspects. This is hard earned knowledge that we accumulate and apply towards a better sound.
The thing with conditioners is that they can do as much harm as good and balance is critical:
Anything in between the mains wall socket and the power input of the equipment is going to be bad, even a just few centimetres of cable will have a resistance to current flow and an eagerness to act as an antennae gathering interference, both bad.
But, the state of pollution of mains electricity worldwide is awful and this is something which has crept up on us massively over the last few decades with now very often in excess of a volt, sometimes several, of high frequency hash carried on top of the legitimate voltage waveform. And this is really, really bad for trying to resolve every subtle nuance, phasing and clue from a musical presentation.
We quickly discovered, because we listen intensively to every step we take, that that achieving more decibels of noise reduction for the spec sheet was very easy but definitely not desirable:
We noted that taking away HF hash liberated electronics. By not having signals blurred, smeared and buried and not having processes swamped by supersonic garbage, then being able to concentrate solely on those signals you want; not only source components but amps as well benefited, greatly increasing dynamics, broadening and giving greater depth to the sound stage and definition…….. But go over a line and you go backwards flattening the image and draining the life.
This circles back to my earlier comment that introducing anything in the power line introduces a restriction = bad. With power conditioning you are inserting elements to eliminate the HF noise but which by their nature will also have a negative side.
We went to enormous lengths to correctly identify the sweet spot of just enough cleansing but not too much, but this was not quite so easy as the sweet spot had to hold for a host of very different loads; sources and amps alike, amps of low power through to high power and Classes A through to D. After a very long time with hundreds of adjustments to a series of potential prototypes in countless different audio set ups we arrived at our solution of which we are extremely proud.
The PSM156 (and PSM1512) work by having the optimum degree of noise filtration, also taking care of star grounding, DC offset , surge protection and importantly isolating each connected component from each other so that cross contamination cannot occur. We think we nailed it.
Best wishes – Mike
