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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
22,634 posts
 
"I suspect that in most cases even an oscilloscope would not provide useful information. While it would give a general idea of the overall magnitude of noise and distortion, it would say little or nothing about how the noise and distortion is distributed among what will inevitably be an enormous number of different frequencies."

Al, explain please why that would not be useful?

It would seem to me that if I can simply isolate the noise frequencies from the proper AC line voltage frequency, that would be sufficient to be able to measure noise levels before and after any change. Specific frequencies involved in the noise would not matter, though it might be informative in terms of helping to identify potential sources of noise perhaps, if one should care.

BEing able to measure noise levels overall on a scope, if possible, would seem to be a better alternative than merely guessing based on what one might hear. That would take a lot of teh mystery out of power conditioning benefits case by case if viable.
hifiharv OP
351 posts
 
You all make good points. Yes, the system was tuned by ear over a long period of time. Cables, tubes, isolation, etc. All chosen for synergy and musical pleasure. Any change, be it higher or lower voltage, fresh transformer and wire, etc. will show up in stark relief. We can't expect the elecricity fed into our house to be benign any more than we can say "all cables sound the same". As audiophiles I think we are all intricately aware of how our system sounds. Others may not even notice, but any slight change will be immediately apparent. Even moving a cable can upset the balance for a few days.
Good point from Al that if power voltage has changed, then rebiasing may be in order. The Amps are the Fisher 30A's and are not adjustable. Tubes are all healthy, a mix of great old European and USA brands chosen by ear. Again, I'm not sure what voltage was before the changes and didn't take the time last night to check. I did get the time for another listen though. I will start a new thread for Day 2 to keep this discussion current. I am resisting the temptation to change anything at all until much time has passed. At least weeks, maybe even a month.
almarg's avatar
almarg
9,670 posts
 
03-20-14: Mapman
Al, explain please why that would not be useful?
Hi Mapman,

I think oscilloscope measurements would be unlikely to be useful because:

(a)The noise and distortion that is present on the AC will consist of a complex and probably time-varying mix of essentially ALL frequencies extending far up into the RF region, at many different amplitudes, including broadband noise as well as noise and distortion components at discrete frequencies. Most likely the amplitudes at some of that near-infinite number of frequencies will be higher after the change than before, and some will be lower after the change than before. There's no way to predict how a specific component in a specific system will react to that complex mix of differences.

(b)An oscilloscope won't provide much if any detail about that complex mix of differences anyway. It will pretty much just give an indication of the amplitude of the overall sum of everything, and perhaps also the amplitude of SOME of the discrete frequency components. Whether that overall sum is more than or less than what was present before would tell us little or nothing, because the sensitivity of the system components to noise and distortion at different frequencies within that sum will be different.

(c)There is also no way to predict whether ANY of the differences in noise and distortion that may be measured would have any relevance at all to the sonic changes that are perceived. How can we know, for instance, whether a small change in line voltage, a small change in contact integrity somewhere, the breakin possibility some of the others have referred to, or some other effect, will or won't be more responsible for the perceived change?

I learned many times over during my EE career that from a practical standpoint some things are inherently unpredictable, and can be determined only by trial and error. A good design will have as little sensitivity as possible to unpredictable variables, but no design is perfect.

Best regards,
-- Al
jea48
4,670 posts
 
Hifiharv,

Did you get a chance to look at the new electrical panel?
Manufacture, style, and series? Info should be on the inside of the hinged cover door.

Also would like to know if the AHJ, (Authority Having Jurisdiction), in this case the electrical inspection department in your area follows NEC 2011 and or NEC 2014 Code and required AFCI, (Arc Fault Circuit Interrupter) breakers for the 120V 15 and 20 amp outlet branch circuits feeding areas, rooms, as required by NEC Code.

http://www.nachi.org/arc-fault-circuit-interrupters.htm

http://www.afcisafety.org/qa.html

http://en.wikipedia.org/wiki/Arc-fault_circuit_interrupter
.
Thanks,
Jim
mapman's avatar
mapman
22,634 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.
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