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Thread: AC cables

  1. #1
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    AC cables

    I've been reading a lot about "high-end" mains cords, and I thought i'd share some info from an electronic engineers viewpoint.

    First of all, i'm not sure how one or two metres of expensive cable is supposed to make much of a difference over a cable distance of a few kilometres. Think about how the power got to the powerpoint in the first place. I don't think that many power supply grids are wired using audiophile mains cable! Add this to the "cheepest they could find" cable the electrician used for wiring the house. The two metres of audiophile mains cord is, at this point, seeming futile.

    Lets assume that you live in a city wired completely from the power station to the houses with audiophile cable, and that the electricians all used the same. Alternatively, lets assume that you use a power filter (after all, the power station probably produces a lot of electrical noise over the supply anyway). You now have to understand the type of current you're dealing with. ac. ac power is ussually 50Hz or 60Hz - right in the low audio range. It is therefore noise in itself (yes, that power you paid so much to protect for two metres is noise anyway). The manufacturers are well aware of this problem, of course, and therefore after rectification to DC they use filtering in the form of capacitors and sometimes inductors. The capacitors compensate for the dips in the rectified voltage which removes the ac noise. The better the filtering in the power supply stage, the cleaner the available voltage rails for the amp.

    To cut a long story short, the $500 and up two metre lead doesn't have a hope of making any difference, however improving the filtering of the power supply rails could prove very worthwhile (providing the manufacturer has not already gone to a lot of effort in this area - most can be improved!). Power supply mods are also fairly inexpensive.

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    Music Junkie E-Stat's Avatar
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    Quote Originally Posted by buffle
    I've been reading a lot about "high-end" mains cords, and I thought i'd share some info from an electronic engineers viewpoint.
    Have you ever sampled any?

    Quote Originally Posted by buffle
    First of all, i'm not sure how one or two metres of expensive cable is supposed to make much of a difference over a cable distance of a few kilometres.
    Reverse your thinking. It is the first two meters. The villains to be filtered are found throughout your house, not at the sub station. Ever use a water filter? Here is an alternative perspective by the engineer behind the fine GamuT audio products:

    Another engineer's perspective

    Quote Originally Posted by buffle
    To cut a long story short, the $500 and up two metre lead doesn't have a hope of making any difference...
    You'll never convince those whose opinion is based upon direct experience. The differences I hear are indeed subtle, but present. Removing RF from the signal removes a slightly bright haze from the sound allowing more musical detail to be revealed. Just last night I plugged the CD transport and DAC in my vintage system into a power conditioner and experienced the same kind of benefit.

    rw

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    Yoiks!!!...

    Quote Originally Posted by E-Stat
    ...You'll never convince those whose opinion is based upon direct experience. The differences I hear are indeed subtle, but present. Removing RF from the signal removes a slightly bright haze from the sound allowing more musical detail to be revealed. Just last night I plugged the CD transport and DAC in my vintage system into a power conditioner and experienced the same kind of benefit...
    ...If you have enough RF, that for some reason (most likely wire orientation) is entering your system through a power cord, and is having an audible effect on it, there may be some reason to seek out a cord with shielding to ameliorate the problem...and that's only if relocation doesn't help...however, it is far more likely that the RF is impinging on your electrical service everywhwere but those last (or first, if you prefer, I won't get into the debate over the semantics involved with that one) six feet of wire.

    A power conditioner may be the answer for this and other power-related problems, but to compare a passive device such as a PC with an line conditioner really undermines your credibility IMO.

    BTW, when visiting my local Borders recently I thumbed through a couple of Stereophile/TAS-type mags...seems as though Shunyata is advertising it's $99 PC and they have gone to great pains to make it obvious that the cord has a UL rating! Not certain what it means, but my gut feeling is that It may be a first for them.

    jimHJJ(...maybe it's the (j)neutron effect...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

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    "We are never deceived, we deceive ourselves" -Goethe

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    Music Junkie E-Stat's Avatar
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    Quote Originally Posted by Resident Loser
    A power conditioner may be the answer for this and other power-related problems, but to compare a passive device such as a PC with an line conditioner really undermines your credibility IMO.
    The cords I refer to all have filter networks and use multiple shielding strategies. They're not just wire n' plugs as you seem to assume. The CDPs in my systems (a significant source of RF) are all located very close to the amplification. I also use a range of conditioners that are all passive in nature.

    rw

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    Here is an experiment I did last year.
    In my study I use a Teac 300 system with Wharfedale Diamonds 8.1.
    Out of interest I took the Isotek Titan,Minisub and Kimber PK10 and PK14 Palladian Powercords and wired the Teac's up through these.
    Could 3000 of Mains equipment improve a 600 System?

    You better believe it.

    It was a revelation, not that I advocate doing such a buy as a first system, but it just shows the difference it can make. And as E-Stat rightly said it is these first one or two meters that need to be taken care off.

    Peace

    Bernd
    "Let The Earth Bear Witness."

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    I to hear an improvement with my $49 PS Audio Power Punch ac cord over the cord that came with the Cambridge Audio Azur 640A. The sound is cleaner and more dynamic. I can not explain why but there is an improvement. I do not know if spending more money on a power cord will give better results in my system but the Power Punch is an improvement and well worth the money.
    JohnMichael
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    Exclamation Pardon my astonishment...

    Quote Originally Posted by Bernd
    Here is an experiment I did last year.
    In my study I use a Teac 300 system with Wharfedale Diamonds 8.1.
    Out of interest I took the Isotek Titan,Minisub and Kimber PK10 and PK14 Palladian Powercords and wired the Teac's up through these.
    Could 3000 of Mains equipment improve a 600 System?

    You better believe it.

    It was a revelation, not that I advocate doing such a buy as a first system, but it just shows the difference it can make. And as E-Stat rightly said it is these first one or two meters that need to be taken care off.

    Peace

    Bernd
    ...but there was a time when even the most rabid aftermarket afficionados qualified their claims with phrases like "...the effects are subtle at best..." and "...require highly resolving (read: expensive)systems..."

    Now even that last vestige of plausible pretext is passe' ?

    jimHJJ(...zut alors!...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

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    And to my further astonishment...

    Quote Originally Posted by JohnMichael
    I to hear an improvement with my $49 PS Audio Power Punch ac cord over the cord that came with the Cambridge Audio Azur 640A. The sound is cleaner and more dynamic. I can not explain why but there is an improvement. I do not know if spending more money on a power cord will give better results in my system but the Power Punch is an improvement and well worth the money.
    ...

    ...another iconic totem bites the dust...

    Upon visiting the PS Audio site, I find that the holy-of-holys, the oft venerated hospital-grade connector is now considered second-rate...of course that's because they don't use 'em and have something new to entice the tweakier of the breed...and none of this sets off the bells and whistles?

    I'll bet JR is p!$$ed...

    jimHJJ(...oh mon Dieu!...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

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    Pardon my French but...

    Quote Originally Posted by E-Stat
    The cords I refer to all have filter networks and use multiple shielding strategies. They're not just wire n' plugs as you seem to assume. The CDPs in my systems (a significant source of RF) are all located very close to the amplification. I also use a range of conditioners that are all passive in nature.

    rw
    ...IMHO the whole thing is residus de taureaux!

    If your CDPs are a significant source of RFI, it isn't simply the power cords...the units themselves radiate this stuff, just like PCs(personal computers that is) and nearly every electrical processor-driven device...If I were to "scan" any such device with an inductive, amplified probe and suitable test transducer, I would "hear" predominantly 60Hz AC at the cord and the lower artifacts of higher freq digital hash depending of the area of the device being probed. Of course the limits to be heard would be below 20k...anything above it goes into ultrasonics...so attempting to filter out anything above 60Hz via a line cord doesn't quite do it...same with ICs, filtering anything above 20kHz won't stop it...it's the devices proximity to the amplifier that accounts for any RFI or RFI induced sonic abnormalities.

    If you ever heard inductive noise, realized the level amplification required to make it an audible problem and took into account the frequencies that actually comprise the realm of RFI, it would be obvious how much of a non-issue it is in actual practice when applied to our little slice of the frequency pie.

    Even if your cords and cables incorporate specific band-pass filters, it's like closing a window on a house with no roof.

    jimHJJ(...and that analogy you cited earlier?...I'm not quite sure it holds water...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

  10. #10
    Music Junkie E-Stat's Avatar
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    Quote Originally Posted by Resident Loser
    ...IMHO the whole thing is residus de taureaux!
    Your loss my friend. I find experience a far better teacher than theory alone.

    rw

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    Quote Originally Posted by E-Stat
    The cords I refer to all have filter networks and use multiple shielding strategies. They're not just wire n' plugs as you seem to assume. The CDPs in my systems (a significant source of RF) are all located very close to the amplification. I also use a range of conditioners that are all passive in nature.

    rw

    So i'm guessing that these cables somehow convert ac to DC then - that would make life hard for the transformer! If not, you're still getting 50Hz or 60Hz noise through because that's what ac is (sort of). By using inductors and capacitors in the power supply ALL the noise and ripple is removed anyway, regardless of what cable you use. To prove this, get a good oscilloscope. Probe the voltage rails. If they are totally smooth, then you have no noise and therefore a cable and power conditioner worth billlions of dollars won't help, it's pure DC. If you find ripple, then do some work on your power supply. Place appropriate inductors in series between the power supply and amp, and large value capacitors (1 use 12 x 3300uF low impedence in my amp) in parrallel. Once you have achieved no ripple, you have the perfect supply (assuming adequate current) and no cable can make a perfectly straight line straighter.

    P.S. A few years back there was an engineer who designs and sells drivers and 'high-end' speaker cables who invited some 'audiophiles' in to his lab to witness for themselves the difference between speaker cables (I think he did this more than once). During the tests he had technicians behind the speakers to change the cables between auditions. They showed the critics each cable before each trial, from zip cord to very expensive models. The critics were amazed at the difference the cables made. The trick was that the technicians would never actually swap the cables. I encourage you to read the article at http://sound.westhost.com/cables-p2.htm#spkr-leads

    Also on the subject of speaker cables, has anyone taken the time lately to calculate the cross-over point of a 6dB filter with the inductance and capacitance of 3m of 12AWG zip cord? You might be suprised.
    Last edited by buffle; 03-29-2006 at 05:03 PM.

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    If you can't run-walk. Bernd's Avatar
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    Quote Originally Posted by Resident Loser
    ...but there was a time when even the most rabid aftermarket afficionados qualified their claims with phrases like "...the effects are subtle at best..." and "...require highly resolving (read: expensive)systems..."

    Now even that last vestige of plausible pretext is passe' ?

    jimHJJ(...zut alors!...)

    No problem Jim. I was astonished too. I heard what I heard and when my wife asked me if I had changed the study system as it sounded so much better I knew I wasn't imagening things.
    Doubters always want scientific proof. I can't provide that, all I can do is share with fellow members my experiences. How can you proof emotional involvement, because I believe that's what happens. The music played through a system powered by clean mains will connect better with the listener. In the end we (or you) the purchaser have to make those buying decisions.
    I left the Isotek Minisub in the study and bought the new Nova for my listening room.
    So all is well and I would not be without mains products anymore.

    Peace

    Bernd
    Last edited by Bernd; 03-30-2006 at 04:57 AM.
    "Let The Earth Bear Witness."

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    As do I

    Quote Originally Posted by E-Stat
    Your loss my friend. I find experience a far better teacher than theory alone.

    rw
    Interestingly enough, I tried a few aftermarket power cords in my system and did not experience any differences of any kind. I do use a power conditioner which helped tremendously and apparently it cleaned up and RFI/EMI problem I had.

    My experiences with power cords challenge the theory that we hear what we want to hear, though! I was ready to buy but no sale. I'm happy to hear, however, that you have noticed improvements in your system, something you would have denied yourself had you been only a theorist.

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    Music Junkie E-Stat's Avatar
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    Quote Originally Posted by musicoverall
    Interestingly enough, I tried a few aftermarket power cords in my system and did not experience any differences of any kind. I do use a power conditioner which helped tremendously and apparently it cleaned up and RFI/EMI problem I had.
    The only other benefit with using a PC vs a conditioner in some cases is with a high current power amp where many folks report dynamic constriction. Apparently, you have already realized the benefits.

    Quote Originally Posted by musicoverall
    My experiences with power cords challenge the theory that we hear what we want to hear, though! I was ready to buy but no sale.
    Same for me in a different setting. About a year ago, a friend of mine brought over his Kimber Palladians (2 of the 10 gauge variety for my amps and a 14 gauge one for my CDP) to compare with my JPS Labs. In this case, my bias was that the Kimbers would NOT provide any further improvement. I was sure that they would be no better than what I was using. I was genuinely surprised.

    rw

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    Well Bernd...

    ...in my previous post re: "plausible pretext", I was going to say: what's next, the old "...my___________(insert appropriate friend/relative here) heard the difference while getting in the car, at the shopping mall, on the way home..." routine, but I didn't want to get too snotty...can the tire analogy be far behind?

    My point is, there are so many diverse and seemingly incompatible anecdotal supports for the whole PC/interconnect thingee, that surely someone, somewhere, who is currently a believer, has to look at it from a less emotional POV and see that 2+2 is adding up to anything but four.

    Please don't take this as personal, because it isn't, but...where are the numbers, surely there are numbers that support the contentions made...oh, yeah we don't know what to measure for...after all how can you quantify God?

    We have the exercise in semantics over last few feet vs. first few feet...then there's line conditioners...then specialized power cords...after all these insulating layers, I quite surprised no one has taken to advocate the POV that the listening room, or at least the electronics, be installed in a Faraday cage...but since some of the offensive RFI/EMI comes from the components themselves, that would necessitate the individual isolation of each and every component in their very own enclosure.

    There are governing bodies like the FCC and such which set guidelines for how much cr@p these gizmos can spew and how far they can spew it. Then of course, since that hash comes from within, how do we isolate the power, processing and signal path from each other? I mean induced noise relying heavily on strength and proximity and all...The manufacturers do shield the internals and they do isolate the AC (and all the nasty stuff that goes with it) in the power section... what with the rectifiers and filters and such...

    But audiopiles are constantly second-guessing the engineers..."...well, they couldn't do that because it would be too expensive..." Are we still dealing with rarefied, expensive, highly-resolving systems? Or are we gonna' slap an $1800 PC on the ol' Onkyo? It seems to me if you're already spending $5-10k for a pre-amp, another grand added to the MSRP for a whiz-bang, mfr. supplied PC is no biggie...Oh but wait, no, no, no the cognescenti must have their freedom of choice...Hmmm, yeah OK...Other than one hand washing the other, I really don't think the manufacturers really give the proverbial r@t's @$$...although I'm sure the pocket-protector set in the R&D get a good laff over it...

    Another question, why such a range of prices? If you can do the bulk of the shielding job with a $99 PC, why the need for the $1800 model? Conversely, if the higher priced cord is the way to go, why bother with the bargain-basement? Oh yeah, well we didin't want to leave out the entry level buyers yada, yada, yada...Something smells and it ain't heat-shrink tubing...

    When I do any serious listening, and while I can't really do anything about the fridge's compressor, I make sure the dimmer-controlled, dining room light is off...

    jimHJJ(...that's pretty much the extent of my concern...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

  16. #16
    If you can't run-walk. Bernd's Avatar
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    Quote Originally Posted by Resident Loser
    ...in my previous post re: "plausible pretext", I was going to say: what's next, the old "...my___________(insert appropriate friend/relative here) heard the difference while getting in the car, at the shopping mall, on the way home..." routine, but I didn't want to get too snotty...can the tire analogy be far behind?

    My point is, there are so many diverse and seemingly incompatible anecdotal supports for the whole PC/interconnect thingee, that surely someone, somewhere, who is currently a believer, has to look at it from a less emotional POV and see that 2+2 is adding up to anything but four.

    Please don't take this as personal, because it isn't, but...where are the numbers, surely there are numbers that support the contentions made...oh, yeah we don't know what to measure for...after all how can you quantify God?

    We have the exercise in semantics over last few feet vs. first few feet...then there's line conditioners...then specialized power cords...after all these insulating layers, I quite surprised no one has taken to advocate the POV that the listening room, or at least the electronics, be installed in a Faraday cage...but since some of the offensive RFI/EMI comes from the components themselves, that would necessitate the individual isolation of each and every component in their very own enclosure.

    There are governing bodies like the FCC and such which set guidelines for how much cr@p these gizmos can spew and how far they can spew it. Then of course, since that hash comes from within, how do we isolate the power, processing and signal path from each other? I mean induced noise relying heavily on strength and proximity and all...The manufacturers do shield the internals and they do isolate the AC (and all the nasty stuff that goes with it) in the power section... what with the rectifiers and filters and such...

    But audiopiles are constantly second-guessing the engineers..."...well, they couldn't do that because it would be too expensive..." Are we still dealing with rarefied, expensive, highly-resolving systems? Or are we gonna' slap an $1800 PC on the ol' Onkyo? It seems to me if you're already spending $5-10k for a pre-amp, another grand added to the MSRP for a whiz-bang, mfr. supplied PC is no biggie...Oh but wait, no, no, no the cognescenti must have their freedom of choice...Hmmm, yeah OK...Other than one hand washing the other, I really don't think the manufacturers really give the proverbial r@t's @$$...although I'm sure the pocket-protector set in the R&D get a good laff over it...

    Another question, why such a range of prices? If you can do the bulk of the shielding job with a $99 PC, why the need for the $1800 model? Conversely, if the higher priced cord is the way to go, why bother with the bargain-basement? Oh yeah, well we didin't want to leave out the entry level buyers yada, yada, yada...Something smells and it ain't heat-shrink tubing...

    When I do any serious listening, and while I can't really do anything about the fridge's compressor, I make sure the dimmer-controlled, dining room light is off...

    jimHJJ(...that's pretty much the extent of my concern...)
    Hey Jim,

    I hear you and agree with a lot of what you say. And yes the often quoted Tyre analogy is pure BS. I only mentioned my wifes response as she very rarely coments on the quality of the sound.
    All I can give you is that when I remove every mains product the system sounds less engaging. Still good but not at full potential and this is with a dedicated Mains spur and meter. I can demonstrate this over and over again. Can I meassure it - NO, but I can hear and feel it. That's good enough for me.That really is the only yard stick I use. Will I miss it once it's gone? Yes - it stays and cost me money; No - it goes.
    I am a very sceptical SoB and if snakeoil or something else does not do what it should do it get's returned post haste. An item either works for me or it doesn't. End of story.
    How is life your end anyway?

    Peace

    Bernd
    "Let The Earth Bear Witness."

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    Bernd, I've said this before...

    ...the optimum situation would probably be a dual-mono pre-amp feeding two mono-blocs, getting their AC from two dedicated circuits each fed by service from two different segments of the power grid...at least line-induced crosstalk might be eliminated...

    Ahhh! spring...The sun is early and high in the sky, the birds are singing their songs of love...rebirth is nigh!...the buds are showing on my Japanese maple, the neighbor's bulbs are sending up shoots...and the friggin' windows on the rolling boom-boxes are lowered and the rugrats are beginning to stir...they're all crawling out...can't wait for fall. Gotcha'...heh-heh...

    Can't complain I suppose...after all, who would listen?

    Got the chance to listen to the first disc of the Bach partitas, as performed by Paul Galbraith, I had previously mentioned...I like it...but I also like Bach generally and, being a guitarist, I also like solo guitar...this eight-string variation presents a much wider range...and I always think some of these players have four arms, given the complexity of some of the pieces with their counterpoint melodies, it's almost like a duet...

    Eventually I'll get the chance to sample the second disc...My listening thus far has been via my old Sennheiser 414s and the el cheapo supremo GPX portable CDP ($7US after rebate) as I was doing some other things...eventually, eventually...I'll try to give it a better venue...

    The liner notes mention his luthier and the other fellow who constructed the auxilliary resonance box...and...and...the fact that the recording studio uses Monster cables...That's the second one I've seen touting specific cables...I think the first was on LAGQs "Guitar Heroes"...

    jimHJJ(...I always try to find a way keep my posts on topic...yeah, right!...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

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    Quote Originally Posted by buffle
    So i'm guessing that these cables somehow convert ac to DC then - that would make life hard for the transformer! If not, you're still getting 50Hz or 60Hz noise through because that's what ac is (sort of). By using inductors and capacitors in the power supply ALL the noise and ripple is removed anyway, regardless of what cable you use. To prove this, get a good oscilloscope. Probe the voltage rails. If they are totally smooth, then you have no noise and therefore a cable and power conditioner worth billlions of dollars won't help, it's pure DC. If you find ripple, then do some work on your power supply. Place appropriate inductors in series between the power supply and amp, and large value capacitors (1 use 12 x 3300uF low impedence in my amp) in parrallel. Once you have achieved no ripple, you have the perfect supply (assuming adequate current) and no cable can make a perfectly straight line straighter..
    What node point do you recommend as the ground reference? The center of the cap bank, the input ground, the output ground, or, the outlet ground?

    Quote Originally Posted by buffle
    Also on the subject of speaker cables, has anyone taken the time lately to calculate the cross-over point of a 6dB filter with the inductance and capacitance of 3m of 12AWG zip cord? You might be suprised.
    I was unaware that the L and C of a speaker wire formed a 6dB filter..
    Didn't you mean to say....with a load at the other end, one which determines the 3dB breakpoint? Without a load, the cable will assume a characteristic impedance way out to the tens of mhz, with dielectric losses starting in that regime..btw, both L and C are lagging mechanisms.

    Perhaps you should calculate the group delay of a lowpass filter...single pole, try using break frequencies of 25khz, 50Khz, 100Khz, and 200Khz..you will find something very interesting..

    Cheers, John

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    Quote Originally Posted by Resident Loser
    ...the optimum situation would probably be a dual-mono pre-amp feeding two mono-blocs, getting their AC from two dedicated circuits each fed by service from two different segments of the power grid...at least line-induced crosstalk might be eliminated...
    jimHJJ(...I always try to find a way keep my posts on topic...yeah, right!...)
    No, No, No, No. Whattayouze...NUTS???

    You set sumptin reediculouse as dat up, and youseis gonna fry.

    That's why da good lord made cloud to cloud strikes,,,to utterly destroy any piece of equipment which is connected to a sufficiently large loop of conductive material..

    Segments of a power grid indeed...Yes, a Darwin award waits for those who try this..

    And Faraday would greet you at the holy gate...to tell you he told you so..


    Cheers, John

    Hey dude, how's it shakin?

  20. #20
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    Picky, picky, picky...

    Quote Originally Posted by jneutron
    No, No, No, No. Whattayouze...NUTS???

    You set sumptin reediculouse as dat up, and youseis gonna fry.

    That's why da good lord made cloud to cloud strikes,,,to utterly destroy any piece of equipment which is connected to a sufficiently large loop of conductive material..

    Segments of a power grid indeed...Yes, a Darwin award waits for those who try this..

    And Faraday would greet you at the holy gate...to tell you he told you so..


    Cheers, John

    Hey dude, how's it shakin?
    ...I mean if you lived on the border and your right channel was powered by substation 'A' and the left one (I got yer left one) by substation 'B' and there was no difference in potential between the neutrals and you used a common local ground and...and...and...aw, hooey...screw the crosstalk!

    Figured you would show up eventually...tings is good...how goes the floor and such?

    Spring is here and it's time to commune with nature...and deck sealer...and brick pointing...and roof repair...and window work...and plastering...and...cheez I can't wait for fall and some mindless leaf-bagging...

    jimHJJ(...'tis a long journey...)
    Hello, I'm a misanthrope...don't ask me why, just take a good look around.

    "Men would rather believe than know" -Sociobiology: The New Synthesis by Edward O. Wilson

    "The great masses of the people...will more easily fall victims to a great lie than to a small one" -Adolph Hitler

    "We are never deceived, we deceive ourselves" -Goethe

    If you repeat a lie often enough, some will believe it to be the truth...

  21. #21
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    Quote Originally Posted by Resident Loser
    ...I mean if you lived on the border and your right channel was powered by substation 'A' and the left one (I got yer left one) by substation 'B' and there was no difference in potential between the neutrals and you used a common local ground and...and...and...aw, hooey...screw the crosstalk!

    Figured you would show up eventually...tings is good...how goes the floor and such?

    Spring is here and it's time to commune with nature
    jimHJJ(...'tis a long journey...)
    Floor's done..18 inch porclean tiles, mint...

    Cabinets in, all appliances (with my fav, a 52 bottle wine chiller), granite comes today.

    Nother coupla weeks, I'll actually be able to start fixin me up a workshop. Just bought me a behringer fbq1502, a 1RU baby eq with a sub out. Unbelievable, 79 buckaroonies...I can't even buy a 1RU blank rack box from sescom for that...nevermind the guts.

    Gonna rebuild the ol' dual cd/mixer box to include this baby eq, so I can eliminate the 2RU unit I built in '78 (oh man). It was difficult building it back then, what with all the veloceraptors and such chasin me..

    Then those 128 4 inch units is just screamin to be used..

    Course, there is this widdle issue of the back yard...seeins as there ain't no backyard anymore..nuttin but dirt..I gots me a shuvel wit me name on it..brick, slate, barbee-que, landscapin ties, drainage tubers..you know da drill..

    Boy, I can't wait to use my superconducting dual-coaxial/quadaxial low B-dot, matched impedance, helium filled, cross/recrossed/crossdressed/wonderlitzefied speaker cable on those speeekers that look like rocks next to the azealia bush..the liquid helium spot market's in a slump right now, so deals can be made!!! Act now, supplies are limited..

    Cheers, John

  22. #22
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    Quote Originally Posted by E-Stat
    The only other benefit with using a PC vs a conditioner in some cases is with a high current power amp where many folks report dynamic constriction. Apparently, you have already realized the benefits.


    Same for me in a different setting. About a year ago, a friend of mine brought over his Kimber Palladians (2 of the 10 gauge variety for my amps and a 14 gauge one for my CDP) to compare with my JPS Labs. In this case, my bias was that the Kimbers would NOT provide any further improvement. I was sure that they would be no better than what I was using. I was genuinely surprised.

    rw
    The Cardas wire I use now was one I secretly hoped wouldn't be "The One". It sounds great in my system but it sure isn't as nice looking as, say, the Audioquest Mont Blanc or a few others I tried. So much for bias dictating what we hear!

  23. #23
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    Quote Originally Posted by jneutron
    What node point do you recommend as the ground reference? The center of the cap bank, the input ground, the output ground, or, the outlet ground?


    I was unaware that the L and C of a speaker wire formed a 6dB filter..
    Didn't you mean to say....with a load at the other end, one which determines the 3dB breakpoint? Without a load, the cable will assume a characteristic impedance way out to the tens of mhz, with dielectric losses starting in that regime..btw, both L and C are lagging mechanisms.

    Perhaps you should calculate the group delay of a lowpass filter...single pole, try using break frequencies of 25khz, 50Khz, 100Khz, and 200Khz..you will find something very interesting..

    Cheers, John

    What I wrote was a simplified statement. I am a QUALIFIED electronic engineer with many years experience in the audio field. I didn't want to start quoting a whole lot of formulae and mathmatical proofs on a forum. Obviously the cross-over point (-3dB of course) is affected by the load.

    Assuming the reactive load would be easily handled by the amp, the effect of the capacitance of the cable would be similar to placing a capacitor of equal value in parallel to the speaker. If you determine the cross-over point, you can see what freqs would be affected. The inductance would be series.

    Group delay should also be insignificant for any decent cable (including decent zip cord over, say, 3m) because the cross-over points are so far above the audible range.

    Once again, these comments are simplified. I certainly welcome further input.

    To put in perspective the comments about measurable vs audible differences and unexplicable improvements, lets clarify something. Electron flow. Voltage is the difference in charge between two points. Current is how much of that charge is actually being allowed to flow between those points - the electron flow. Maybe some of these cables are teaching the electrons quick-step tai-chi or jazz balet during their mystical journey through the conductor. (and yes, I know there are differences in inductance, impedence, capacitance but these CAN be measured and assesed)
    Last edited by buffle; 03-30-2006 at 01:41 PM.

  24. #24
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    Quote Originally Posted by buffle
    What I wrote was a simplified statement.
    Agreed.
    Quote Originally Posted by buffle
    I am a QUALIFIED electronic engineer with many years experience in the audio field.
    I, however, am licensed by the state of new york to operate a 157 kilowatt potential to kinetic energy conversion unit.....anywhere within the continent of North America..(as long as I stay between the lines and obey the signs and rules.

    Why do you feel the need to tell me you are qualified for anything? Did I say you weren't??
    Quote Originally Posted by buffle
    I didn't want to start quoting a whole lot of formulae and mathmatical proofs on a forum.
    Why not?? Granted, it is indeed difficult to post the equations as this forum doesn't support the extended ISO-8859 character set. But hey, don't be shy..at least we can get superscripts and subscripts. If you really really feel the desperate urge to post equations, just write them down and jpeg em..
    Quote Originally Posted by buffle
    Obviously the cross-over point (-3dB of course) is affected by the load.
    ..you didn't mention a load before. Course, that load varys wildly from about an ohm to 20-30. And your reference to a 6dB filter...since you now talk of two reactive elements, I can assume you are speaking about a second order network of 12dB/octave vs a 6dB/octave first order? For typical speaker cables which are wildly off the load impedance, the cap is essentially not involved, so that would be a L-R first order, as I think you meant.

    Quote Originally Posted by buffle
    If you determine the cross-over point, you can see what freqs would be affected. The inductance would be series.
    Well, yes. And??

    Quote Originally Posted by buffle
    Group delay should also be insignificant for any decent cable (including decent zip cord over, say, 3m) because the cross-over points are so far above the audible range.
    Hmmm..You obviously didn't consider what I said. I said calculate the group delay. Your response was "should also be insignificant"?

    What do you consider as insignificant? Are you aware of the ITD levels which humans use for localization of a source in space? Or the IID?

    For a cable impedance which doesn't match the load Z, as zip cord certainly does not, the inductive energy storage dominates. Not only does it introduce a group delay which affects differential localization, but attempts to minimize the line storage via geometry or dielectric change will force the cable to take on a distributed LC, which no longer is a simple second order line, further changing the group delay.

    Do yourself a favor. examine the group delay of a first order low pass..

    Take the phase response, which is -tan-1omega, (in degrees) and multiply it by the period of omega in microseconds per degree.. You will find it asymptotically approaches a non zero value..

    Now, model a speaker run by breaking it into smaller and smaller elements..then tell us what the final group delay is..don't worry, it will asymptotically approach a final value if you wrote the code correctly.

    Quote Originally Posted by buffle
    To put in perspective the comments about measurable vs audible differences and unexplicable improvements, lets clarify something. Electron flow. Voltage is the difference in charge between two points.
    Hmm...As I recall, voltage was the difference in potential between two points. If two points have the same capacitance to an arbitrary reference node, then voltage will indeed be related to the charge..(it is indeed amazing what someone with a drivers license can know..)

    Quote Originally Posted by buffle
    Current is how much of that charge is actually being allowed to flow between those points - the electron flow. Maybe some of these cables are teaching the electrons quick-step tai-chi or jazz balet during their mystical journey through the conductor. (and yes, I know there are differences in inductance, impedence, capacitance but these CAN be measured and assesed)
    The fundamentals are far more important. To assess the impact a transmission media has on the perceived images sought after via two source reconstruction, one first needs to understand what parameters are important towards that reconstruction.

    Cheers, John

  25. #25
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    Quote Originally Posted by jneutron
    Agreed.

    I, however, am licensed by the state of new york to operate a 157 kilowatt potential to kinetic energy conversion unit.....anywhere within the continent of North America..(as long as I stay between the lines and obey the signs and rules.

    Why do you feel the need to tell me you are qualified for anything? Did I say you weren't??

    Why not?? Granted, it is indeed difficult to post the equations as this forum doesn't support the extended ISO-8859 character set. But hey, don't be shy..at least we can get superscripts and subscripts. If you really really feel the desperate urge to post equations, just write them down and jpeg em..
    ..you didn't mention a load before. Course, that load varys wildly from about an ohm to 20-30. And your reference to a 6dB filter...since you now talk of two reactive elements, I can assume you are speaking about a second order network of 12dB/octave vs a 6dB/octave first order? For typical speaker cables which are wildly off the load impedance, the cap is essentially not involved, so that would be a L-R first order, as I think you meant.


    Well, yes. And??


    Hmmm..You obviously didn't consider what I said. I said calculate the group delay. Your response was "should also be insignificant"?

    What do you consider as insignificant? Are you aware of the ITD levels which humans use for localization of a source in space? Or the IID?

    For a cable impedance which doesn't match the load Z, as zip cord certainly does not, the inductive energy storage dominates. Not only does it introduce a group delay which affects differential localization, but attempts to minimize the line storage via geometry or dielectric change will force the cable to take on a distributed LC, which no longer is a simple second order line, further changing the group delay.

    Do yourself a favor. examine the group delay of a first order low pass..

    Take the phase response, which is -tan-1omega, (in degrees) and multiply it by the period of omega in microseconds per degree.. You will find it asymptotically approaches a non zero value..

    Now, model a speaker run by breaking it into smaller and smaller elements..then tell us what the final group delay is..don't worry, it will asymptotically approach a final value if you wrote the code correctly.


    Hmm...As I recall, voltage was the difference in potential between two points. If two points have the same capacitance to an arbitrary reference node, then voltage will indeed be related to the charge..(it is indeed amazing what someone with a drivers license can know..)


    The fundamentals are far more important. To assess the impact a transmission media has on the perceived images sought after via two source reconstruction, one first needs to understand what parameters are important towards that reconstruction.

    Cheers, John
    Settle down, mate!

    I cited my credentials because as a designer of audio and RF circuitry, I feel that I should be in a position to also recomend a suitable cable with which to couple it.

    I'm glad that new york lets you run a motor. You might want to reexamine your point on voltage. The potential difference between two points IS the difference in electron charge between two points, or nodes. As you agreed, the cable WOULD act as a first order. Designing audio and RF filters is part of my living, so you're not going to impress me. Do you really want a pissing competition or is this just a hobby forum?

    The reason I haven't gone into detail is because it's just a hobby forum, it isn't that important. I, unlike you, feel no need to prove myself. If you genuinly want to discuss signal transfer and filter characteristics then fly to Western Australia and study with me. You are right about the affect of group delay on possibly perseptive freqs, but are recording studios employing the hardware to accurately record this?

    Have you read the comments on speaker cables from one of the most respected people in the business (GDS). After all, his comments are available on this site. Do you also feel more qualified than him on the subject?
    Last edited by buffle; 03-31-2006 at 02:30 PM.

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