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I'd like to expand on the points I made in the thread below:a) A poor setup can lead to an incorrect conclusion. For details on this please read the post linked below. I was listening in an unoptimized room, and *adding* a connection in the signal path made an apparent improvement. This is, of course impossible, and optimizing the room allowed me to hear this very clearly.
b) If we accept the premise that an optimized room is a better evaluation tool, NOBODY has addressed the fact that an apparently great-looking room can still be a poor evaluation tool if it is contaminated with high levels of locally generated RFI (Wi-Fi, cell phones, cordless phones, et cetera).
Follow Ups:
nt
I've been looking at what factors might lead various reviewers to various conclusions. For example, one reviewer thought that the three different CD players all sounded essentially the same, with only very minor differences. I think most people that have spent time with these units would probably come to a different conclusion.One factor may be the listening environment. Another potential problem is the fact that most reviewers' systems are constantly in a state of flux. I know that it is much easier for me to discern small (but meaningful) differences when the system has been stable for a long time and I am quite familiar with the sound. In general, reviewers don't have that luxury.
I agree with all of that. I really need to work on my room and placement of rack etc. Charles--I read your post about putting the ICs/Speaker cables on wood blocks, especially for carpeted floors. I have hardwood floors (with a Persian rug in the center) and my cables are on the wood floor. Do you think it would be a big improvement to put the cables on blocks over the hardwood? What would be the expected sonic outcome? 50 bucks is a cheap tweak, if it makes a difference.
A friend who has an even more revealing system than mine has hardwood floors. He has experimented with a variety of lifters, and presently uses maple wedges (tall triangles). The cables rest upon the sharp edges.I use stiff paper cylinders on end. You can make lots of these for a few dollars with the stiff poster stock and school glue sold in dollar stores.
nt
< < Do you think it would be a big improvement to put the cables on blocks over the hardwood? > >I haven't tried this, but a friend who did said that it helped. I would guess that it would make a smaller difference than it does with a carpeted floor.
< < 50 bucks is a cheap tweak, if it makes a difference. > >
Try $15 first. Go to Target and get a kid's game called "Jenga". It has 50 wooden blocks, which is enough to treat almost any system. They don't sound quite as good as the myrtle Golden Ratio blocks, but if you don't like what they do you can always give the game away to somebody's kids.
nt
I believe your points are very valid. I just returned from CES and a side trip to the east coast where I heard several systems. Room tuning can be affected by the simplest of things, rearrangement of furniture, etc. and to great effect.
One thing I did notice that all too many rooms and systems had problems with absolute polarity, which is usually unrecognizable for most listeners but something which annoys me. At one room at CES, I was allowed to rearrange the polarity and the effect was rather startling. We did this after hours, of course, but the room exhibitor was very pleased with the results. He reported that on the next day, listeners were constantly commenting about how good his speakers were (he designed electronics). One dealer who owned the speakers himself went up and closely examined the set up and said his system had never sounded that good. He noted some changes we had made. but failed to notice that the electronics and the tweaking was essential for the performance.
On my side trip to the East coast, similar results were obtained in the one system I was allowed to touch. A reversal of polarity lead to great improvements in clarity, sound staging and detail.
In a day where we have access to resistors in the hundredths per cent accuracy and distortion levels in equipment can be vanishingly low we need to return to real unamplified music for a true reference and to be aware of other issues.
... is likely to improve only half the discs being played, this strikes me as a bit odd. Were all the test discs in the "wrong" polarity relative to the way the system was set up originally?Or are you talking about something other than ACOUSTIC polarity?
I take it you have not resorted to experimenting with the absolute polarity of your system. It seems, and admittedly I am assuming so I could be very wrong in this (if so, I do apologize), that you have simply accepted the 'facts' which CJ states. While I charitably attribute most issues to software, there are also many other aspects, including transducer time alignment which further cloud the issue and the perception.
... by "rearrange the polarity" and how such rearrangement impacts on the reality that there is simply no consisency in the polarity exhibited by different CDs, LPs and other media. For me, it's enough of a pain in the butt just to switch speaker cable when my polarity-coherent speakers tell me that it would be a good idea.
Polarity is difficult to demonstrate by writing, and needs to be experienced. That has been my experience, and in various conversations with designers and engineers, while most are very familiar with the technical ramifications of polarity, very, very few have actually auditioned systems in and out of polarity. For example, I spoke to the VP and president of California Audio Labs once and asked why they had a polarity switch on their automotive DACS, and none on their home units. Their reply was that no one used it or had asked for it, including all of the reveiwers. One user I met refused to use the polarity switch simply because the light came on and that additional light bothered him.
You are not alone in finding that swapping speaker wires seem to be far more troublesome than the gains in performance seem to be worth. I simply find it quixotic to find that listeners are willing to spend vast sums of money on audio gear which often have little semblance to reality (at least to acoustical instrumentation). Much dissatifaction with audio gear can be traced to this issue, which the ear can recognize as being 'wrong'.
... and I still don't see how it relates to "rearranging the polarity." Yes, polarity switching is easy to hear now that I have polarity-cohenrent speakers. And once you do, changing polarity at the speaker terminals upon hearing a disc that is clearly in the "wrong" polarity is not an option unless I'm feeling lazy. That said, it's really not a big deal -- not a deal at all -- if you can't hear the difference. And with many or most speakers, you can't. I can't, for instance, detect it on any speakers other than my own. And believe me, I've tried.
One can enjoy wine, televisions, cars, sailboats, etc. the same in different locations. Context doesn't matter much. I grant that it is hard to demonstrate cars and sailboats at shows but reviews have greater verisimilitude. We have managed to get along in this circumstance for many years, but there is a major problem. I think many need to realize the limitations we have in conveying what we prefer and what it sounds like in our rooms. The number of people whose ears and comments I trust gets smaller each year.
c
One's environment can make a huge difference to the enjoyment a good wine offers.And there's another mind altering substance that was quite popular in the '60s and '70s, the experience of which had a HUGE dependence on one's surroundings. But you may not know what I'm talking about.
Regards,
Geoff
was that it tasted like paper.
a
x
Linn's Ivor Tiefenbrun banned regular plain old telephone sets (POTS) from the rooms dealers used to display his turntables and speakers...in the quest for a fair demonstration of his products.P.S. Has anyone ID'd the reviewer of the room in question. It would be google sleuthing at its best.
laptop pc and cell phones do affect sound quality.when i did the pc test previously, i couldn't hear any difference. this time i did. but...., surprise, surprise, bass frequencies "fatten" up, and imaging focussed more solidly in the centre fill with the laptop turn on, and even more so, when explorer was turned on.
i think some english audiphiles may prefer the sound with laptop and explorer turned on. it sounded a little boosted with a touch of naim's prat.
...if you're talking about the one below in Charlie's first room post, just look down at the bottom for the url.
(nt)
...many people feel a system sounds better with a preamp in the system, when it can be run without one?Is this a matter of adding favorable colorations to create a more musical sound?
By the way, it is great to see you back on the forums.
The more I think of Charles response to this question, the more disatisfied I become with it.To answer this question appropriately you need to consider the an electrical circuit in its basic terms, a device with three basic properties Voltage, Current and Resistance. In a system without an active preamplifier e.g a resistor based attenuator, the voltage of the circuit is varied following the time honoured V=IR formula, if you consider the formula, you will notice that there is cost for this, i.e. increased impedance (or resistance). An 'active' preamplifer on the other hand, introduces an active device (transistor or tube, both functionally equivalent in this application) can vary the voltage without a corresponding increase in output resistance, of course there is a price for this of course, the noise floor of the active device is typical higher than that of the typical passive element such as a resistor, but that penalty pales in a comparison to the advantage the active device brings to the table.
So it is not case of "adding favorable colorations to create a more musical sound". It is a case of less is less without an 'active' preamplifier, as the resistor based less so a transformer based attenuation are restricted devices in comparison to 'active' preamplifiers, as their attenuation comes with a stiff penalty, much higher output impedance. And as an aside, I think RFI has very little relevance in this scenario.
Music making the painting, recording it the photograph
I wish I had a great answer for you, but I don't.When we first started Ayre, we used a passive preamp between our reference CD player and our power amplifier (our first product). We quickly found that different passive preamps yielded different levels of performance, and went through a few of these. By far the best sounding was a custom-made fixed attenuator comprising a pair of rhodium-plated connectors soldered back-to-back with two resistors permanently soldered in place to give a single fixed volume level. No switches, no wires, just two connectors and two resistors. (All of the passive preamps and attenuators were plugged directly into the inputs of the power amp, so there was no issue concerning driving an interconnect cable.)
So when we made our first preamp, I was wondering just how much *worse* it was going to sound compared to our reference fixed attenuators. I was stunned to find that it sounded *better*.
There was a very slight loss of resolution, but that was more than made up for by increased focus of each instrument, improved weight and impact in the bass, a larger soundstage, and a greater sense of musical ease and flow.
I'm really not sure why this was so, but it certainly was. Here are a couple of possibilities:
a) The power amp was more sensitive to RFI than was the preamp. Somehow the preamp was filtering out RFI that was getting through the passive preamp.
b) The output impedance of our reference fixed attenuator was around 900 ohms, while the output impedance of the active preamp was 300 ohms. It may have been that the input stage of the power amp "preferred" seeing the slightly lower source impedance.
I find neither of these explanations to be very satisfying, in that I don't think they are telling the full story. But here it is ten years later, and I still don't have any better idea what is really going on here. However, I am quite confident that (at least in this case) it is *not* a case of "adding favorable colorations to create a more musical sound".
d
tune a room around a system based on a below par cd player (which sound no better than a portable cd walkman) isn't gonna get anywhere either.in the case of that ts guy, he was listening to both players on headphones. the room acoustics don't even begin to figure here. neither would speaker set-up, cabling, and equipment placement. and does it also matters the room is contaminated with high levels of locally generated rfi (wi-fi, cell phones, cordless phones, et cetera)?
the portable with its plastic chassis logically would be more adversely affected, but hey, why then would it sound better? maybe his ayre player was simply more susceptible to rfi pollution than the portable?
To make it very short:
I have found that “noise” over 10Mhz is not a problem. If it is a problem it can indicate bad equipment layout or make up.
power cables, I find that RFI is responsible for the "apparent" improvements in some systems using aftermarket power cords. I am unconcerned about the quality of the switching station. I am concerned, however, of the effect of my four computers, two wireless access points, five CD/DVD players, three digital cable boxes and four cordless phones on the resulting sound of my systems. They are the villains. I have also seen many manufacturers quietly strengthen their RF trapping methodologies.Some argue that amplifiers that are "improved" that way are improperly designed. I submit that RFI is a highly variable and fairly new problem that engineers simply didn't have to worry about in the fifties/sixties/seventies.
and the web sites for the power cords you so loudly proclaim are wonderful have no spec's when it comes to RFI attenuation.
d.b.
for the effectiveness of their shielded power cords either. I use 83803 in one of my cables and 19364 in two others. Go figure.
If you want a working RFI filter you use.............
are you ready for this???????????????/
are you sitting down????????????????/
Here we go.................
YOU USE AN LC FILTER!!!!!!!!!!!!!!!!!!
Just like the stuff that Corcom etc puts in can, or a Tripplite Isobar.
Wire is not a filter, now go back and review AC electronics 101 and get reaquainted with reality.
d.b.
Don't you worship at the alter of Belden like SM?
Volex # 17660; Braid and foil shield for generally under $15.00.
And now for the next question; since you're so adept at putting up links maybe yopu would like to try and explain to me and the rest of us just exactly what the link you posted is saying, because from my experience with you on this is that you really don't understand what is being said or not said as the case may be.
One final note: The shielding is only as good as the ground the shield is connected to.
LMAO as usual;
d.b.
The Volex is a good, but not great answer for low current devices. I would most certainly not use a wimpy 18 gauge cord with my 10 amp tube monoblocks. I believe it grounds the braid at both ends which may not be desirable in all cases.How do shields work? Shields are conductive layer(s) that trap stray signal (RF) with lowered transfer impedance. Some are aluminum. Better ones are copper. (I doubt that the budget Volex uses copper braiding.) Yes Dan, they selectively filter HF. With AC wires, the braided shield becomes the bouncer to drain the undesirables to ground. I chose to connect the braid of my 83803 flavor only at the plug end away from the component.
So, how is the collaboration with SM going on your next exciting alcoholics piece?
"The Volex is a good, but not great answer for low current devices."
What do you base this assumption on?"(I doubt that the budget Volex uses copper braiding.)"
I think you are wrong here: the foil is aluminum, and the braid is copper."Yes Dan, they selectively filter HF. With AC wires, the braided shield becomes the bouncer to drain the undesirables to ground. I chose to connect the braid of my 83803 flavor only at the plug end away from the component."
Ever look at the frequency response of this and compare them to an LC filter such as Corcom etc. and Tripplite?
Is that cable 30 to 40 db down at 1 Mhz?
"I chose to connect the braid of my 83803 flavor only at the plug end away from the component."
Why, whats wrong with a low impedance return from the chassis to earth?
I don't think you've done your homework here. You appear to be just doing the usual high end marketing dance.
Tell us; how much do you get paid to put up these silly posts? Do you get discounts on new equipment as a reward?LMAO as usual;
d.b.
The bitterness of your folded tent has become you. Speaking of which, how's that campaign to "marginalize the high end" going? Contacted S.P.E.C.T.R.E? You're sounding like this guy:
What do you base this assumption on?
If you want to use 18 gauge for regular 10 amp duty, have at it.
Ever look at the frequency response of this and compare them to an LC filter such as Corcom etc. and Tripplite?
A. I prefer using a combination of active and passive (shielding) strategies where useful. Each has its own role.
B. I will be happy to view that information. Since Belden (nor subsidiary Volex) provides such, then by all means present your evidence.
Only speculations. You do make it so easy for me, it's really laughable.
LMAO as usual;
d.b.
I have far more important things to do than to respond to your childish interrogations. It is they I find tiresome. On the other hand, I have humored them from time to time. You just don't like my responses!And of course, the current one concerning how shielding works.
nt
there ought to be a merit badge for you.So, how's your article on NFB for alcoholics going with SM?
So, if you believe that RFI is important, the design of the antenna from the isobar to the power supply is important.Given that, a simple shielded volex power cord seems to do the job just fine.
Will the shielded cable help then?Try this link: http://www.audioholics.com/techtips/audioprinciples/interconnects/bulletproofingsysteminterf.php
Go back and read it again. Maybe look for the word ISOBAR.
My apologies.
d.b.
HiOne might think that, what has happened is that there are vastly more low power devices which radiate above 900MHz (Cell phones, wireless links like Blue tooth etc) than ever before.
Below that, the average noise level has fallen as they eliminated spark gap florescent starters, industrial equipment having mercury rectifiers, renegade CB stations and such.
Until the governments HAARP program began (which can be a bummer for short wave listeners) the range from the 10 meter band down was much quieter.
AM stations all meet spurious radiation limits now and such as well.So, the situation is one where the number of weak, high frequency sources is vastly greater while the average RF background level noise is lower than it used to be.
The up side of localized hf noise like this is that a ferrite core around the cable decouples the noise.
When in doubt, these cores are cheap and many clamp around an existing cable.http://dkc3.digikey.com/PDF/T071/1239.pdf
http://www.skycraftsurplus.com/index.asp?PageAction=VIEWPROD&ProdID=891Best,
I'll try some out with the Belden 19364 I use on the transformers to my 'stats.
that may be more unpleasant than the cure they provide. Different ferrites have different flavors, so experiment before abandoning this approach.Your 'stat supplies may be strong RF noise sources, so more elaborate filtering may give more improvement.
< < Unfortunately, ferrites have sonic flavors that may be more unpleasant than the cure they provide. > >That's for sure. The funny thing is that the sonic problems often don't show up for days (or sometimes weeks). Apparently, they somehow become magnetized, because demagnetizing them with a bulk tape eraser makes them sound better again. At least for a few more days...
On the other hand, I find experimentation with such things enlightening. I'm perfectly willing to invest/throw away ten bucks for directly experiencing the answer. :)
right at the AC input jack of the gear (amp/preamp, whatever)
and good basic shielding/grounding practices INSIDE the gear,
practices which have been understood for over 50 years --then
you can take the $1800 "audiophile" AC cord and pitch it into
the nearest waste basket because it then would have nothing
whatever of use to add in way of additional shielding. Sad,
but very true. Even cheap interconnects can be made which
have a very high level of broad-spectrum RFI shielding. No
exotic materials or esoteric construction needed --again just
sound established design.IMHO, there are no good excuses why so many high-end manufacturers
seem to avoid taking even these basic steps to ensure proper
RFI shielding. It's like they never bothered to pay attention at
all to the radio engineering people. As a Ham radio operator who
uses multi-hundred watt transmitters and receivers which are
sensitive to two-tenths of a millonth of a volt (just like any
other radio guy) I have to laugh at how much money is absolutely
WASTED on silly snakeoil bandaids because some guys $20K "high-end"
preamp, CD player, whatever can't supress the tiny milliwatt RF hash
on the powerline generated by the power supply of a $1500 personal
computer or a $5 "wall wart" cell phone charger. What a Joke...And then some clown comes out with a $5000 "A.C. purifier" or
$1800 power cord as a "solution".What a carnival of the absurd.
-T.M.
No one addresses that issue yet daletech (wwww.daletech.com) addresses that issue for medical use power cords. I'm surprised more audio manufacturers have not checked out this particular issue.
Hey Stu,So ya thinks too much distibuted 'Y' capacitance can be deleterious to your listening pleasure? Do a search on the whole asylum for 'unicable', or for my personal fave -
Hopefully, more manufacturers will revisit their designs in that regard.What I am most amused over is those simplistic EEs who don't acknowledge that RFI can be an audible issue in high resolution audio systems. There was one old TV repairman over at AR who stated that power cords couldn't possibly make any difference. Naturally, he had ZERO personal experience with such, but he felt confident of his ability to speculate. Ignorance can be bliss. :)
.
No Guru, No Method, No Teacher
Do you happen to have a suggested vendor and/or part number for such an AC line filter suitable for a high-power (400W into 8 Ohms) audio power amp?
Mouser of Digikey. I'm sure there As long as it mates with the
AC line amperage drawn. Remember, if you have RFI noise issues,
improper cabinet shielding, input and or speaker output grounding,
interconnect shielding/grounding and somilar can also be culprits.
But, the AC line filter is a very good and obvious start.Good Luck.
nt
< It certainly has gotten worse in domestic environments, but rest assured it's now a standard EE sub-discipline. The roots, I think, go back to designing equipment that works in the presence of (eg) radar gear--that's WWII-era. But in those days applications outside ships and airplanes were pretty rare--though an acquaintance of mine once loaned me a book on how to sniff out RFI that was written for homeowners. Seemed to be focused on improving your television reception, though it noted applications to amateur radio as well. Published in the '70s, I think. In those days, of course, they didn't have things like broadband over powerlines.Standard textbook is by Henry Ott. And the standard design goal--embraced by all competent professional engineers--is to build equipment that performs "perfectly" effected in an RFI environment. What an engineer calls "perfectly," however, may not be acceptable to an audiophile. Beyond that, I know almost nothing.
Not much is truly new.
Yep; the basics and the application were done years ago. The only problem as I see it is to get the consumer audio industry to agree on a grounding standard and figure out just exactly how are they going to use a three prong plug. BTW: just in case you weren't aware of it, good grounding practices reduce interference.
It's my understanding--never made the measurement, which isn't easy--that even a reasonably effective earth ground can have several ohms or more between it and true, ideal earth ground. So noise on the ground line isn't necessarily immediately sucked right down into the ground where it can't do any harm.Also, it has been my experience--which admittedly is limited--that there are lots of houses out there with lots of receptacles that are not properly grounded. It seems to me that you would want your equipment to function reasonably (and be safe) even in such installations.
I wonder if someone (Dan? Charles?) can help me understand what, if any, are the implications of these two facts for designing audio electronics.
Any takers?
The purpose of the third power wire (commonly called the 'ground') is to provide an independent path for fault current in order to trip the circuit breaker before the faulty equipment can kill someone.The purpose of the earth attachment is to limit the power system potential rise in the event of a lightning strike. In most USA installations, the utility step-down transformer secondary center tap is attached to earth at the transformer, and each customer's entrance panel is also attached to earth. The earth is not a very good conductor, and there can be many ohms of resistance between these points. Lightning has sufficient force to overcome this setup if it strikes too close, but the arrangement does provide some protection against induced surges.
There is much confusion in audio because circuits contain zero reference points called 'grounds' and this sounds a lot like the term used in the power wiring nomenclature. The impedance between any point in a circuit and the zero reference point depends on the wavelength: for the audio band in domestic situations, all wires are "short" and can be considered as simple lumped elements of resistance, inductance, and capacitance. However, for higher frequencies, the distance becomes a factor and the wire must be treated as a transmission line.
Some audiophiles with technical training and who should know better have installed independent earth connections for the AC circuits feeding their equipment, and report improved performance. This leads to the idea that the quality of the earth connection is important for audio performance, and questions such as yours. An independent earth connection is a very bad idea for safety reasons, but I won't go into detail here.
The quality of the earth connection is important for the safety reasons listed above. It has an influence on the noise environment of the audio system, but not for the reason you stated. The noise environment includes the frequency ranges from audio through UHF and possibly beyond. The safety-earth wiring, no matter how well made, is far too long to be an effective 'ground' connection for much of this frequency range. Modifying the safety-earth wiring will change the noise environment, but not eliminate the basic problem.
Equipment that is double-insulated can avoid connection to the safety-earth power wire and any noise carried on that wire. This is the best solution that I can see. Unfortunately, much audio equipment requires connection to the safety-earth for safety. The noise that enters the system through these connections limits the ultimate performance. Audio systems contain their own noise sources, so this ultimate limit may not be relevant if the internal noise sources have not been addressed.
If earth ground is for safety only then I would like to note the following.
If we look at your typical AC line input filter schematic from Corcom. we note a small cap going to earth ground.
If we look at how a screen room is constructed we note that the entire metal housing of the screen is earth grounded.
If we look at some of the chassis's that are used in some instrumentation we note that the chassis has a fine mesh metal screen over the fan, and in addition the chassis will also contain adhesive copper fingers that are placed along the internal sides to reduce the discontinuities of the chassis.
In balanced connections pin 1 of the XLR connector on much of pro equipment is connected to earth and is typically called "shield".I also note that in talking with a computer technician that he can't use his cell phone and work on an open computer, he has to close it up. It would appear that the earth grounded case of the computer is acting as a shield for the HF frequencies in the above example.
It would appear from the above that certainly a fairly large part of the electronics industry uses earth ground as a shield.
d.b.
is a large part of the problem. Those line- and neutral-to-ground Y-caps couple RF noise from the line and neutral onto the safety-earth wiring, where it then goes into the audio system to degrade the performance.Attaching shields to earth is important for DC and lower-frequency RF, but has no relevance for the higher-frequency noise that modern appliances generate and that mixes with the audio signal inside most gear and at any corroded connections. The safety-earth wiring is just another complex antenna and distribution network for this noise.
I admit it has been a long time ago and I forgot a lot of what I learned, but I woulda thought a physics PhD would have made it possible for me to understand this stuff.My problem is that both Dan and Al, to varying degrees and at different times, seem to be referring to ideal conditions and how things should be, while at other times noting (in different ways) that (very common) imperfect implementation can compromise performance. "Safety" ground is only for safety--sure, I knew that--but it can affect performance. I knew that, too.
I own two residences. One is in the country, near a transformer, in a very quiet environment. The other--where I spend most of my time--is an 11-story condominum complex. I can do anything I want with the former, but I have very little control over the wiring in the latter, except for what happens inside my little corner.
One thing I've discerned--I think--is that a designer has to decide whether to design for an ideal electrical environment or a real, compromised one. If I have total control over my electromagnetic environment, I'm probably better off buying equipment competently designed for an ideal environment. But for situations--like my condo, where at any given moment I can detect 5 different wireless Internet signals and god only knows what the ground is like--I'm probably better off buying equipment competently designed to function in an imperfect environment.
So, to clarify the question:
1. What choices would you make to design for an ideal electrical environment? For a non-ideal environment?
2. Is it possible to design equipment that functions optimally in both ideal and non-ideal environments? Is equipment designed like this limited in performance relative to equipment designed for an ideal environment?
Okay, so that's more than one question, but you get the idea.
Charles Hansen does not seem to have trouble making well-received gear that does not need the AC safety-earth connection.My AC installation is closer to your ideal than your condo examples, but I've determined that my Wadia 861 delivers better performance if I take measures to keep the RF noise out of its grounded AC supply. The safety-earth is part of the issue.
Surely it cannot be that hard to distinguish short from long wires with respect to the frequency of the noise. The only hard part for most folks is to accept that audio gear suffers from noise through the UHF band and beyond. Whether your AC installation is closer to ideal than non-ideal, the quality of the safety-earth wiring only affects lower-frequency noise. In your condo example, non-grounded equipment would have an inherent advantage for rejecting the lower-frequency noise that is likely present on your safety-earth wiring. I don't see how it would have a disadvantage compared to grounded equipment in the ideal case.
If you have grounded equipment, have you investigated an isolation transformer for your audio setup in your condo? A transformer removes the noise present between the safety-earth and AC neutral by shorting the secondary neutral lead to the safety-earth at the transformer. It also filters normal-mode noise through core losses. This is legal and does not require rewiring your building. The downside with most transformers is their limited current delivery capacity. The Acrolink transformer is way over-built and performs well.
"1. What choices would you make to design for an ideal electrical environment? For a non-ideal environment? "
From the aspect of the electronics alone; a properly wired three prong outlet."2. Is it possible to design equipment that functions optimally in both ideal and non-ideal environments? Is equipment designed like this limited in performance relative to equipment designed for an ideal environment?
From the aspect of the electronics alone; a properly wired three prong outlet.
Hope that answers your question, and as you implied in your first post; the theory and applications where done at least thirty years ago.
http://www.audiocircle.com/circles/index.php?topic=8780.0
The above link is a good start; Bill Whitlock recommended that a switch from the signal ground to the chassis/earth ground at the return of the power supply for each unit would give manufacturers and users the options they need.
d.b.
what, precisely, means "properly wired"?
Please see the electrical code, but in general; the hot and neutral are not crooswired and the earth ground goes back to main panel, connected to preferably an incoming water pipe. Since some don't have an incoming water pipe they can use a properly connected stake in the earth, or in the case of some larger apartment the steel frame of the building which can and in many cases is tied to earth ground.
ATTENTION! Please consult an electrician for what is applicable in your residence, as I have outlined some general case scenarios and do not attempt to do any of the above on your own. As for you Jim: consult with an electrician or electrical contracter on what is required.
d.b.
> > As for you Jim: consult with an electrician or electrical contracter on what is required. < <
I am not sure an actual ground connection is required for a closed metal enclosure to keep RFI in, (or out!)It is far to long since I studied this, but such an enclosure, originally called a Faraday cage simply needs to be a fully enclosed conductive "wrapper".
In cold-war days it was beleived that keeping your emergency transistor radio in a biscuit-tin would make it immune to EMP from a an atomic bomb. I never did this experiment.
Yes; a Faraday cage is an option; however, the ready, cheap availability of a three prong plug for many appplications does have plenty of things going for it.
d.b.
the wiring is ancient or incorrect and not up to present day standards. For starters I would recommend some reading on the electrical code for earth grounding under different situations. Many of us who live in urban/suburban areas have the earth ground connected to the incoming water pipe. This makes a very suitable earth ground as the pipes on the incoming side must be conductive/metal, The waste side can be non conductive, to the best of knowldge.
Another thing you can do is go to Home Depot and try to find a two prong outlet, and then ask yourself the following: When was the last ime I saw a computer or microwave oven with a two prong plug? The three prong plug has been around for at least twenty years and it is up to the house owner to bring the property up to present day code.
I urge folks who rent to work with the property owner on this, as I did many years ago.
For an earth ground to be as bad as some people claim; I would suggest that calling in an electrician to verify that your residence is up to present day code.
d.b.
Dan, you are correct. In any modern construction, the waste feed to the street is typically spec'ed as schedule 40 PVC. Water feeds from the street are copper tubing, usually taken directly off of a spool to keep a contiguous run from the street valve to the meter valve.I've built 3 houses in the past 20 years and they were all done this way.
And now you know why I say to people the following:
Call your electrician first!
d.b.
Good grounding reduces hum, yes, but not necessarily RF.
RF noise travels on the AC safety earth wiring. Audio equipment with casework attached to the AC safety earth contains deliberate or accidental (or both) pathways that couple RF noise to the audio signal. Awareness is the first step towards understanding.
< < Audio equipment with casework attached to the AC safety earth contains deliberate or accidental (or both) pathways that couple RF noise to the audio signal. > >That is my experience, too. That is why the Ayre gear uses double insulation -- so that we don't have to connect the case to the AC safety ground. Sounds much better that way.
So the rest of industrial electronics and scientific instrumentation
have it backwards? Or are you guys just victims of bad house wiring & coroded earth grounds?
ROTFLMAO
d.b.
Gee, Dan. It's easy to see why your products sounded so good and your company was so successful.
Answer the question Charles. Why does the rest of electronics not have the issues you and AL S. are having?
d.b.
Well, at least you stopped rolling on the floor. Maybe it will be easier to actually listen now. You should try it some time.
Still ROTFLMAO;
d.b.
Consumer audio is in the mess it's in. Mistaken attitudes and misinformation such as you have posted are in direct contradiction to what the rest of electronics already knows, and has known for many years.
I don't mean to be a snot here Ozzie, but that's the way it is.
d.b.
Try this link; http://www.audioholics.com/techtips/audioprinciples/interconnects/bulletproofingsysteminterf.php
Sorry to get you in Dutch with Charles. I don't disagree that proper AC grounding can reduce RF. Can! But it may not necessarily do so, as the original posters implied, by using expensive AC cables. Now to me, that may qualify as missinformation. Not by the poster, but by the manufacturers of the cables. How many of those high dollar cables are bought to resolve a problem that simply does not exist? Or that if the power supply and cabinent grounding of the component was properly done, incoming RF would be pretty much a non issue as was mentioned above as well? It sounds like Charles' grounding scheme works quite well. At a much lesser cost than an 1800 dollar cable.
< < It sounds like Charles' grounding scheme works quite well. At a much lesser cost than an 1800 dollar cable. > >Sorry to disappoint, but everything makes a difference. And the differences are cumulative. Using a good power cord helps the sound even when using a good grounding scheme.
In other words, I haven't found a grounding scheme that negates the need for good sounding power cords. Just like nobody has yet made a DAC that sounds the same with all CD transports.
On the other hand, there isn't always a direct correlation between price and performance. You might be able to find a nice sounding power cord for less than $1800.
< < It sounds like Charles' grounding scheme works quite well. At a much lesser cost than an 1800 dollar cable. > >Sorry to disappoint, but everything makes a difference. And the differences are cumulative. Using a good power cord helps the sound even when using a good grounding scheme.
--- Care to qualify that statement? When there is no problem with RF in the first place for one's application, why bother with any AC power cord tweak? Because they look cool and will impress one's friends with the latest purchase? I bought a Digital AC cable for my Sony 777 just to see if it would make a difference. It made no difference whatsoever to the sound. I guess either I don't have externally generated RF or the chokes on the AC input are doing their intended job. Luck or good engineering? I'll take either as I am results oriented.
In other words, I haven't found a grounding scheme that negates the need for good sounding power cords. Just like nobody has yet made a DAC that sounds the same with all CD transports.
--- Why not just include one in with your player in the first place? You can use my response below if you want. I just can't believe that any combination of L & C can cost as much as these cables do. The claims of cryogenic treatments are yet another story altogether.
On the other hand, there isn't always a direct correlation between price and performance. You might be able to find a nice sounding power cord for less than $1800.
--- While I will not dispute that different quantities of L & C may negate RF at different frequencies, it seems that review claims always seem to be made that the higher dollar AC cables sounds better. Hmmm?
< < I bought a Digital AC cable for my Sony 777 just to see if it would make a difference. It made no difference whatsoever to the sound. > >If you can't hear the difference, count your blessings and go buy a few more CD's with the money you saved.
and the only ones which deliver consitent results in indicating what sounds good to me. I am always leary of the ability of rigid
technical protocals and measurement standards to reliably predict
satisfying sonic outcomes.
> > A poor setup can lead to an incorrect conclusion. For details on this please read the post linked below. I was listening in an unoptimized room, and *adding* a connection in the signal path made an apparent improvement. This is, of course impossible, and optimizing the room allowed me to hear this very clearly. < <I agree. I am not very good at listening to subtleties in strange, unoptimized environments. I have made poor choices in audio purchases because of this effect in the past. I tweak for weeks and months to get a major component upgrade to sound its best in my system. I go into things like changing preamp components that flatter a CD player, for instance.
With this in mind, and because my track record for "gut instinct plus positive other opinions" purchases seems to be about equal with my own evaluations in dealers listening rooms on different equipment I went ahead and bought your CX-7e CD player sight unseen. I didn't see the need to drive far to actually listen to it. This is not a new approach for me. I have done it before, and like I said it works out with about the same effectiveness. This is what makes high-end shopping for me so frustrating. I can never just walk into a store, listen to source components, and figure "this is it, it's the best one."
But I at least can tweak like crazy, and even redesign components that go with them so there is finally system synergy. I am confident the CX-7e will sound great in my system after I am done getting it dialed in. Three dealers I talked to were very enthusiastic about this player. In fact there is such good comments that I think very little tweaking will be necessary on this one. That hasn't been the case on my prior CD players.
In the case of my analog setup, that's an evolution over many years. Every aspect of that chain has been tweaked on, even the step-up transformer core stacking effort. If I move, will I have to do this all over again? Dang, the thought of that.
Kurt
how they may sound in a labratory or anechoic chamber!What's an optimized room anyway? Comparing JA's to Dudley's bring to mind the old expression... Some like it hot, some like it not.
An in most things disclosure is the way to go, one can make better judgement of a reviewer's critique when he/she is familiar with the reviewers's preferences, biases, musical leanings, room, etc. etc.
A good room, whether or not the reader has one, will allow the reviewer to know what's happening. A bad room could actually have synergy with a particularly bad speaker where as in a good room it would be obvious.
Let's use the Stereophile rooms offered by JA, his own and Art Dudley's, are both "good", how do we know, is their allowance for personal preference?; I'll admit this last question is rethorical, it almost seems too obvious contrasting the two sample rooms, yet if there's some objective standard of "goodness" feel free to spell it out... don't worry, if there bad news for one of the two esteemed reviewers I'll take on the woeful task and pass on the news. :)
No Guru, No Method, No Teacher
I don't think the point is that there is one "best" way to set up a listening room, any more than to say there is one "best" amplifier (or speaker or whatever).To me the point is that there are known ways to screw things up. For example, putting anything in between the speakers will reduce the image depth and focus. (I know that many people put their equipment rack right there, but a quick listening test will show that this is sub-optimal placement.)
Both JA's and AD's rooms show that they were paying attention to the details, and not making the gross kinds of errors that will screw things up. This is in stark contrast to the picture I originally linked to. In that photo, there were at least a half-dozen obvious faux pas that were screwing up the sound.
My other point is that there are other *invisible* ways that people can be screwing up the sound in their listening rooms. For example, installing a Wi-Fi network in the next room over (or worse yet, in the same room).
Now for the average listener, it doesn't really matter if they are "screwing things up". All that matters is if they enjoy listening to music on their system -- it doesn't matter how they get there. But I think that a reviewer has a different job and should be held to a different standard. If their room is screwing things up, how can they be trusted to make credible judgments on the performance of a piece of audio gear?
Take another look at JA's pictures. In one he has a massive Halco standing roughly adjacent and in front a Wilson Sophia speaker, the side of the Halco, which is fully two third the height of the speaker if not more, appearing to act as an outside boundary for the speaker. The arrangement with the other speakers is different so it seems there was no attempt at symmetry (in fact the room is open on the other side relative to the placement of that side's speaker). Now mind you perhaps via trial and error he arrived at that setup as one which produced good sound. The point is that the photo, which makes no attempt to disguise the obvious clutter created by his audio components, testing gear, and computer setup, doesn't strike me as a overtly obvious prototype of a careful optimized setup.Now bear in mind that is not a criticism of JA's setup, in fact I'd say the opposite as it seems to me that his setup very likely shares attributes with the majority of hobbists who *do not* have dedicated, single purpose, listening environments.
As for Art's setup it stands out as a rather obvious contrast to JA's. Given that these two fellows are members of the revirewing elite this would seem to argue against the notion of a particular correct "one way" or even direction to arriving at a satisfactory listening space. In terms of potential problems related to room nodes it seems Dudley's would be more susceptible as the space seem basically a closed rectangle with a not particularily high ceiling (as far as I can tell), yet there are no obvious room treatments such as bass traps (unless I'm missing them).
So overall I really don't see where you're coming from with the suggestion of obvious attention to detail, unless of course the fact that Art's room being a dedicated listening space fits the bill.
But frankly nothing about either of the room causes me any great concern. Oh Art's room is very likely to exhibit an annoying bright sound with crappy components but let's face it the bulk of the stuff he plays with hardly fits that description and moreover his well known prefererences further ameliorate any great concern.
I bother will all these observations only because I have for some considerable time become convinced that the "room" is just another of the tiresome "ojectivist" bugaboos. I don't know how many times I've read some BS about how a few simple room treatments would be *enormously* more effective than spending money on quality components, and typically from guy who believe most all electronics (forget cables!) sound the same anyway, etc.... ad nausea! How many of us have lived with single room for decades on end?... how many of us have had rooms that were a sonic disaster?
Ironically I just visited a friend who has moved to a space that grossly exagerates sibilances and hard constantants, it's obvious just by conducting a conversation. The critical point here however is precisely that the problems *are* obvious, he knows, and I know, something has to be done in that space. Fortunately given the current bare layout and hardwood floor a good Persian, an upholstered sofa, and maybe a tapestry on a wall should work wonders... heck even our work introducing better speaker cables and power cords has already made a world of difference, I can't wait to hear it with the "room treatments" in place!
As far as the conceptual leap from an obvious hell hole to reviewers using Jenga blocks under all their cables well what can I say?... maybe that sort of thing is no biggie to flighty Ayre types but I fear a great many audiophiles would be lost to the canyon in the attemmpt to vault across the divide.
No Guru, No Method, No Teacher
...because perceive an obvious contradiction. You wrote:> > I don't know how many times I've read some BS about how a few simple room treatments would be *enormously* more effective than spending money on quality components, and typically from guy who believe most all electronics (forget cables!) sound the same anyway, etc.... ad nausea! < <
...and then:
> > Fortunately given the current bare layout and hardwood floor a good Persian, an upholstered sofa, and maybe a tapestry on a wall should work wonders. < <
Well maybe I get it. Are you saying that both are important?
From my own experience--and theoretically--I've got to say that the idea that cables could address that problem meaningfully seems wrong. After all, those effects--sibilance, ringing--can readily be mapped onto properties that are easily measurable--and addressable by room treatments. Room treatments have obvious, measurable effects in the frequency and time domain. The effects of cables--well, you can make those measurements, too, but you'll get no change (unless at least one set of cables is defective). And I am NOT claiming that all cables sound the same!
There's a lot we don't understand about this stuff--well, anyway, there's a lot that I don't understand. But there's also a lot that we do understand. It'd be foolish not to bring that to the table.
I'm having a bit of fun with the term "room treatment", i.e. just common furnishings... the things that the vast majority of audiophile get by with!; including JA it seems. The other aspect is the idea that rooms can be, or require, improvement is often overstated... i.e., if it ain't broken...Read Mike Fremer's review on the Tara Labs Zero cables to understand the meaning of improvements via cables. In particular his comments about the Zero's yielding a reduction in "Electronicia", if that was the coinage he used, but basically a reduction in that sense of "electronic" sound is something that is not unique to the Zeros.
In fact for someone moving from a very poor (manufacturer throw-in) interconnect to, say, a good quality Cardas he/she might experience an improvement on the same scale (or perhaps to an even greater degree!) than Fremer did going from his already very good cables to the Zeros; assuming a decent system of course. Think of a cable as something that, subjectively speaking, adds "nasties" to the signal, adds "zing" to sibilance. Better cables add less, do less damage, sound smoother, more natural, more like "no cable". In a overly "live" room any reduction in "nasties" from the cables will be especially appreciated.
Bear in mind that some like the sound that a live room gives, yet that doesn't meant that like electronic nasties!
Charles believes that if it sounds good in a poor environment, such as at CES, it will sound even better at the reviewers or in your home. I think to some degree with experience that you can "listen through the room and even the electronics," but this is an art and I am not confident that it is very accurate. It also means that it may also sound awful in buyer's rooms where they don't want to have to listen through the problem.
As I said below, I fully agree that a reviewer's setup is his or her place of work and laboratory so we owe it to the makers and readers to do the best we can to have it optimized and conducive for the job, the tools appropriate and sharp for the task.But there also can come a point where a reviewer creates an idealized environment which 95% of prospective owners of the gear he reviews can't or won't duplicate. Large conventional bass traps and room treatments are one example. Most living room systems simply won't tolerate their installation as a matter of decor.
Even having a dedicated listening room is something many real-world listeners don't enjoy. They use double-duty spaces.
Installing separate system grounds with copper rods in the yards is something most end users who rent won't ever do - nor many who own their home. Elevating cables on riser above synthetic carpet. There's a long list of optimizations that audiophiles are willing to consider but not regular music lovers.
The best compromise to me is to have full disclosure on the part of the given reviewer, about what his system, setup and room are and look like. Then the manufacturer has hard data to decide whether he considers that suitable and appropriate for his standards while the reader can decide how much weight the conclusions should hold that were made under those circumstances.
And yes, something can look slick and gorgeous but may still sound like shit - a component or a system or an installaton. We all know examples of that, don't we? -;)
And when I worked industrial maintainance we grounded every machine with 6 ft copper rods. You should see the system pics I get from audiophiles either its a packed to the gills room or massive open floor plans and the worst total controled by she who must be obeyed rare I see dedicated spaces or proper set ups.I take this in as I design some types of controled dispersion loudspeakers can do better in average spaces, interacting less with the listening space is usualy a good thing for most dont have it anywhere near optimised.
"Installing separate system grounds with copper rods in the yards is something most end users who rent won't ever do"This is illegal and an incredibly dangerous practice. What can happen here is that in a near lightening strike the current/voltage can travel from one earth ground rod to the other through the wiring of the house. This is not something anyone should wish for. I have a had one piece of equipment returned to me when this happened in a customers system, and I bet he's still wondering why his surge suppressors didn't work.
If you are a responsible reviewer, and check with your electrician on this, please do not recommend this practice to anyone in the future. In fact you would do your readership a service by warning them of the hazards of doing this.
Disregard all of the above if you are seriously trying to win the Darwin award.
d.b.
The ground rod installations I was referring to are fully encapsulated affairs used by Japanese recording studios. While I haven't studied all the specs nor done it myself, I have talked to people who have. Unless I missed something (and some of these were manufacturers of power products), they thought this solution perfectly safe and legal. It was a rather expensive kit that included professional installation by an electrician.
The last I knew it was outright illegal to do this for residential installations. For professional/industrial installations both ground rods must be tied together with something like #2 AWG wire. This is technique is rarely done in industrial applications here to the best of my knowledge.However: This does not excuse you from disseminating this information as something for audiophiles to think of. In short; ignorance of the law is no excuse in this country, and I think you owe your readers an explanation and an apology.
d.b.
Time out. I didn't condone, suggest or recommend any of it, I merely made a mention higher in this thread about certain tweaks some audiophiles are willing to implement which ordinary music lovers wouldn't or couldn't and that hence, there's an argument to be made that reviewers not go overboard tweaking too much since they'd go beyond what the average customer liable to buy the stuff they're reviewing could or would duplicate.Both the Magnan and Galen Carol Audio websites mention specialized earth grounding and I've also seen it references on the PureAudio site. Sound Application had first mentioned a specialty Japanese implementation which he was considering importing as a kit. Not sure whether he ever did. Additionally, I know people who've hired electricians to install these kits to measure a severe drop of impedance on their ground leg with reportedly very audible effects.
That's all she said on that topic and insinuating anything more is putting words in my mouth. -:)
About 8 years ago when I was working on high power radar transmitters we had a 3/8 inch copper pipe that led back to the main panel for a safety ground. It was very effective in discharging 25 Kv and the instantaneous current that went with it.
The point of this is, is that Audiophiles/Recording people seem to love going the most expensive route available, as in digging up the ground to install an additional rod and wiring the two together, when all you needed was a run of copper pipe back to the main panel.
d.b.
Bill Whitlock's Jensen paper on the subject contains this quote: "If multiple ground rods are used, Code requires that they all must be bonded to the main utility power grounding electrode."
"This is illegal and an incredibly dangerous practice. What can happen here is that in a near lightening strike the current/voltage can travel from one earth ground rod to the other through the wiring of the house. This is not something anyone should wish for. I have a had one piece of equipment returned to me when this happened in a customers system, and I bet he's still wondering why his surge suppressors didn't work."I don't think you really understood this Maybe you need time to think about it.
d.b.
That's what I said when I mentioned "back to the main panel"
d.b.
I've got half my back yard dug up... please don't tell me it was all for naught! If you're serious I swear I'm gonna sue that guy!
No Guru, No Method, No Teacher
It seems to me that before one optimises the room, and addresses extraneous interference (RF, etc) it's necessary to optimize the system, particularly:a) have chosen a reasonably sized room (reproduction wise) to place the system; we would expect a reviewer to do this within the limitation of his/her home and spouse, of course
b) Painstakingly position the speakers in the listening room. This is primordial.
This is also very difficult to achieve with "full-range" or purportedly FR spkrs, where the low frequencies are in the same enclosure as the high frequencies (i.e. the case for most of us).
IME there is a very narrow area wherein spkrs operate optimally, where very small movements confer an inordinately high sonic difference.c) Having achieved "acceptable" (or better) spkr positioning, the room's inadequacies can be addressed much more efficiently -- if absolutely necessary.
d) Agreed, as you suggest, lowering the system noise-floor from rfi etccan be addressed at any time -- and, why not, right after the room has been chosen.
Cheers
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