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The sound of my new electrical service: Day 1

And I mean a completely new service. New pole!, new pole transformer!, new underground line to the house (was above ground), new meter, and new breaker box with all new breakers. House wireing remains the same. Talk about an upgrade! Or, will it be a sonic downgrade? I wouldn't be surprised. House was built in 1964, so that stuff was 50 years old.
I don't do much desk work, so typing all these subjective impressions will be quite a bit of work for me. I hope we all can find it interesting at the least. I doubt too many others will have to go through this with their systems, so maybe it's pointless, but might still be interesting. Beforehand, my system was sounding so good that I was afraid to change anything. You know what I mean don't you? If not, I'm sure you will get there eventually.
System: completely restored, vintage tube. Been through the modern stuff, this is the real thing. I will stick to digital VIA CD for the first few days to keep things simple for us.
Day 1: Eric Clapton "Unplugged", Buddy Guy and Jr. Wells "Alone and Acoustic", Ani Defranco "Living in Clip"
Right away I noticed the urge to turn the volume down. I'm usually inclined to turn it up because this system can sound so deliciously juicy with real life timbre and tone. Not sure if it now plays louder at the same volume setting, or if it is just more irritating. On Unplugged the instruments have lost that deliciously right timbre and tone. Total lack of analog like sweetness and the system could even be mistaken for solid state. It has aquired a solid state like impression of power though. Foot stomp/tapping is more audible with a bass like presence. Sibilants, S's are pronounced like they linger too long. Capton's voice is both murky and harsh at the same time. Overall, a great loss of transparency that makes this obviously a recording and not the musicians in my room.
On Buddy Guy, a lack of clarity on the voices. Also irritation when things get peaky. Jr's harmonica is dark and lacking the usual bouncy excitement. Guitar tone seems lacking in higher frequencies. Again though, I hear more intense feet to the floor sounds. Need to play something with bass to see what happens there.
On to Defranco's live disc. If you have any interest at all in this artist, just buy this one. You might not love all of it, but the good stuff is just great. On this disc, the energy is all there, but on the irritating side when things get loud. Voice comes off better than the other two discs, but not at all what I am used to. Bass? Well, it seems tighter, but not better or stronger. Her guitar rings out as usual with plenty of power, but, again the timbre is off making everything less interesting. When the music quiets down, a perception of transparency sets in that approaches what I am used to here.
Thats it for now, stay tuned for day 2, etc. to come.
hifiharv
mapman's avatar
mapman
22,341 posts
 
Al,

All good points, but I still wonder if a scope can be useful for the sole purpose of observing any differences in AC line noise levels before and after an attempted power tweak, say like with and without a particular AC power regenerator or filtering device.

If not, how do the designers of said devices determine how well their designs work or not?

There must be a way that power treatment devices are tested. Otherwise the whole concept of systematically addressing clean power issues (beyond basic amps and volts measures) is highly suspect.
almarg's avatar
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almarg
9,670 posts
 
Mapman, let's take the BrickWall surge suppressor/line filter that I use as an example. Its specs that are relevant to noise filtering, which are certainly measurable as well as probably being analytically predictable to a reasonable approximation, are as follows:
EMI/RFI Filter Response (bi-directional, wave tracking): With 50 ohm Rg load: 3db at 5kHz; 26dB at 100kHz; 38dB at 300kHz.

Let-Through Slew Rate: 5,000 volt/µs disturbance reduced to 28v/µs within AC power wave envelope, and less than 10v/µs outside the power wave envelope.
As with most designs, presumably those characteristics were chosen based on what the designers considered to be a preferable set of tradeoffs between the likelihood of audible benefit; the likelihood of undesirable side-effects; development cost; manufacturing cost; parts availability; physical characteristics; target selling price; marketability; profitability; utilization of available human, equipment, and intellectual property resources; etc., etc.

But can they, or any other manufacturer of such products, predict with any confidence what sonic benefits and/or side-effects will result when a product having those kinds of specifications is used in an arbitrarily chosen system powered by AC having arbitrary and unknown characteristics? The answers to those rhetorical questions seem clear. The bottom line, IMO, being as you stated in your last sentence :-)

Best regards,
-- Al
hifiharv OP
351 posts
 
Sorry Jim, did not get to the box last night. I'll do that tonight along with testing the voltage. Something tells me I don't want AFCI's. We'll see. Not sure what our County's requirements are but passed two inspections on the day of the work.
mapman's avatar
mapman
22,341 posts
 
"But can they, or any other manufacturer of such products, predict with any confidence what sonic benefits and/or side-effects will result when a product having those kinds of specifications is used in an arbitrarily chosen system powered by AC having arbitrary and unknown characteristics? "

REferences I see indicate US AC frequency is 60 hz. Most countries are 50 or 60 hz.

So in US< in essence, isn't "clean" AC power predominately 60hz, and any variations from this "noise"?

Can an oscilloscope make this distinction?

If so I would expect it to be useful to help determine "clean" power.

The effect the AC power, signal noise or otherwise, has on sound case by case or not is another story, out of scope of what I am trying to understandl which is merely how to distinguish noise from clean signal with AC power.
almarg's avatar
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almarg
9,670 posts
 
So in US< in essence, isn't "clean" AC power predominately 60hz, and any variations from this "noise"?
Yes, except that I would say "noise or distortion."
Can an oscilloscope make this distinction?
Yes, mostly. It can certainly distinguish between 60 Hz and broadband noise (within the bandwidth limitations and amplitude resolution capabilities of the particular scope, which for a decent quality scope I suspect would be good enough for this kind of purpose). Relatively large amounts of distortion could probably also be quantitatively characterized in a reasonable manner with a scope. It might not be possible, though, to assess relatively small amounts of distortion (that might still be great enough to have audible consequences in some systems) without a spectrum analyzer or other comparable instrument.
If so I would expect it to be useful to help determine "clean" power.

The effect the AC power, signal noise or otherwise, has on sound case by case or not is another story, out of scope of what I am trying to understandl which is merely how to distinguish noise from clean signal with AC power.
My reference to usefulness was not with respect to determining the degree to which the power is "clean," on an overall basis. It was with respect to usefulness in resolving sonic issues, and/or making purchase decisions about power conditioners and regenerators, in response to your initial question:
03-19-14: Mapman
Beyond the multimeter, which is a logical first step, is there an affordable gadget out there that can be used to actually measure AC line noise? That would take a lot of guesswork out of the equation when attempting to determine value of adding conditioners, regenerators, etc.

I'm thinking an oscilloscope type device could certainly be used but something more affordable and easier for a lay-person to use and get a clear determination of line noise frequencies and levels just for this purpose?
Best,
-- Al
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