Clean those conduit boxes.

I've lived in my apartment for many years. My walls are made of plaster. When I installed my audio grade receptacles in the wall, years ago, I simply put them in, checked polarity and went on my way. Since upgrading to the furutech gtx-d recently, (which is going through burn in hell, see my other thread) I decided to go back into the two metal conduit boxes that feed my system. I made made everything "perfect" and vacuumed the plaster debris that had been in the boxes for god knows how long. Maybe as long as the building has been standing- maybe 50 years. Each box for whatever reason, had a couple of ounces of plaster in it, ranging from pebbles to plaster sand.

Now it sounds actually cleaner, with more micro detail. Not a huge difference, but still a worthwhile improvement. Not sure if the pebbles and sand that were in the box were resonating or what. Could even be placebo- but it certainly gave no benefit being there. So it's gone, and it's one less thing to ponder. Just wanted to share. It could actually be detrimental to the sound if you have junk in the boxes, like I did. Makes sense to make everything as "right" as possible.
That's easy to understand clean boxes = clean sound. My speakers sound much cleaner after dusting too. I have good highs on second floor but better lows in the basement and more "air" when playing outside.
Did you also try Holly Water? If you dip in there, you sound will be more "liquid".
Before I run a cd I put a daunting stare at one place on my system a few minutes and after that it seems to give me a more focused sound. When I put my speaker cables up on risers I seem to notice more space around the music flowing through those cables. It is a funny hobby.
...and if you have high power class A amplifier running you'll probably getting a worm sound especially if you're sitting close to amp:-)
All jokes aside, is it possible that the build up of plaster dust and the like contains some synthetic elements that would have a detrimental effect much in the same way as synthetic elements of say, a carpet and what it does to speaker cables that lie on the floor?

I wouldn't cover my PCs in crap that would be detrimental to the sound so would it stand to reason that all than gunk around the power wires would have some negative effect?

Just food for thought.

All the best,
All jokes aside, what I would wonder is if putting the couple of ounces of plaster back in the box would cause the less clean sound to return.

If (as I suspect) it would not return, it would be an indication that something else was responsible for the perceived change. Perhaps even just having the system unpowered while the cleaning was performed, or just the effects on the contacts of removing and reinserting the power plug.

Which is not to say that anyone would or should bother doing that. But at the same time I would resist the temptation to attribute a perceived change to a seemingly implausible variable in the absence of methodology that is sufficiently thorough to rule out the possibility that something else may have been responsible.

-- Al
Well, so much for thought food. :-)
2 blonds having a discussion on the car that doesn't start
--Did you wipe bumper?
--Did you clean dash-board?
--Did you wipe headlights?
--I have no idea why it doesn't start then!
Tough crowd here.
What Al said for sure.
There is a definite sound improvement after I occasionally cut power to my system and then power it up again.
"There is a definite sound improvement after I occasionally cut power to my system and then power it up again."

In the time-honored words of Click and Clack, the Tappit Brothers: "BALOGNA," "PAA-LLEEASE," and "THAT'S B-O-O-O-O-GUS."

We're not a tough crowd at allÂ…you are bonkers, though.
Bojack, I see no basis for having any doubt about Mark's statement. For several reasons:

1)In my book, his many posts here over the years have earned high credibility for the perceptions he reports.

2)Operating temperature, which obviously would be affected for some amount of time afterward by an interruption in power, is fundamental to the physics and the performance of both analog and digital devices and circuits.

3)Overwhelming anecdotal evidence attests to the significance of warmup effects, in some cases over periods of many hours or even days.

4)If digital circuitry or processing is involved, initialization, resets, clearing of memory, the effects of temperature on risetimes, falltimes, and propagation delays, and other such things that occur when power is cycled can affect both those circuits and coupling of noise from those circuits to analog circuits. For example, I presume you've had occasion to see at times how computer behavior can sometimes be affected or corrected by rebooting.

I say all of that, btw, as someone who I doubt would ever be accused of being at or near the extreme "believer" end of the "believer" vs. "skeptic" spectrum.

And, frankly, your concluding phrase was entirely uncalled for regardless of the correctness or incorrectness of what you or Mark had to say.

-- Al
Getting back to the OPs thread, I did some research on the negative aspects of plaster on power lines and the only thing I could find were a couple of sites. One was a British electricians site where plaster was also asked about and it turns out that modern plaster has no ill effects on wire but older plaster has some corrosive elements in it, especially lime, which eats away at the PVC coating of any wire.

Another site rated plaster as really good at rejecting/blocking RF so I guess it depends on the age and type of plaster so the argument would seem to be whether old, corrosive plaster has a deleterious effect on sound.

I know it is a reach but it's all I could find.

All the best,