vastly<\/em> lower impurities content)<\/p>\n\n\n\nUP\nOCC (what is often called long grain type, and again a differing process).<\/p>\n\n\n\n
Cryo\ntreatments (used to improve copper\u2019s PHYSICAL properties)<\/p>\n\n\n\n
Grain\ndirection (music is AC. Which polarity do you like first and at what\nfrequency?)<\/p>\n\n\n\n
I don\u2019t use wire \u201cquality factor\u201d as\na design element since every contemporary draw science wire is of vastly better\nquality than ever. Sure, some processes are more $$$ but there is scant\nrepeatable measurement that I can do other than conductivity, a passive\nresistive measure that will influence R, L and C. The conductor type is an option\nfor the customer to listen to, only. There are differences. Belden just isn\u2019t\nin the position to create a pet project to define what isn\u2019t yet scientifically\ndefined. That\u2019s not our thing.<\/p>\n\n\n\n
Belden\noffers the three fundamental copper grades; ETPC, OF and UP OCC, as they DO\nsound different in the exact same electromagnetic R, L and C referenced design.\nNo changes other than the copper, so we know what the culprit is. What we don\u2019t\nknow, is WHY it is the culprit. Instead of making up a big old story, again, about\nthe material, we don\u2019t. It is what it is in use and we leave it that way.<\/p>\n\n\n\n
What\nwe don\u2019t offer is what I can\u2019t hear as a designer. Sorry, but I\u2019ve yet to hear\nCRYO treatments, intended to improve the wire\u2019s PHYSICAL strength or grain\ndirection, change the sound. As far as grain direction goes, you can flip the\nleads in any direction you want, as the wire\u2019s grains all go the same way due\nto the manufacturing process that we use. If you can hear the direction switch,\nflip them any way you like. We won\u2019t send you a bill for that!<\/p>\n\n\n\n
Any\nmaterial used in a superior design SHOULD sound as good as it can, and cost\nisn\u2019t a direct line to better sound. I ignored cost when I designed\nICONOCLAST\u2122, either high or low. If my system didn\u2019t allow me to hear it, I\ndidn\u2019t use it (materials) or do it (process \/ design). <\/p>\n\n\n\n
This\nisn\u2019t a paper on conductors, although I may have some things to say about\nalternatives to copper them later on in another paper based on some\nmeasurements and calculations I\u2019ve done. We\u2019re talking copper in this paper as\nit is the very best economical solution that we have right now.<\/p>\n\n\n\n
Copper\nhas a very low DCR, a reasonably deep skin depth to manage current coherence,\nis pretty high in tensile strength for processing, and in most applications\nresists severe oxidation. The grain structure is clearly visible in form, but\nthat alone is NOT what makes the different grades sound different. It is a\ntrait of the draw science, but does not have as much effect on the sound as you would be lead to believe. <\/p>\n\n\n\n
Use\nsolid or stranded wire? This, at least,\nis easy. Is stranded better for the way the cable is used? Is stranded more, or\nless, expensive? Is stranded easier or harder to process? Is the termination of\nthe cable better or worse with stranded wire versus solid? Are any gremlins\nthat I call tertiary variables (stuff there isn\u2019t a measurement or calculation\nfor) removed if the truly measureable variables are accounted for between\nstranded and solid?<\/p>\n\n\n\n
ANSWER\n\u2013 Solid wire wins hands down for this application. Every question is in solid\nwire\u2019s court. End use, costs less, processing cost, ease of termination and\nlack of tertiary elements (all those diode effect \u201carguments\u201d between strands\nand more).<\/p>\n\n\n\n
On\nthat, though, a note: the first generation of Iconoclast interconnects use\nsingle solid wires for the signal-carrying conductors and that’s what’s\ndiscussed in this paper. Our second\ngeneration product (suitable for analog but not for digital due to impedance\nissues) uses a star-quad arrangement of four separate wires, placed around a\nseparator, in place of each of these conductors for improved inductance; for\ndetails see the fourth paper in this series. \nOther than this change in the signal conductors, the “Gen 1” and\n“Gen 2” interconnects are the same.<\/p>\n\n\n\n
1.1 Copper Size \/ RCA<\/strong><\/p>\n\n\n\nWe\nnow have SOLID copper wire. The size selected sets the foundation for the whole\nthing if we consider that the cable\u2019s structure is supposed to allow a\nconductor to be as near zero R, L and C measurement cable as we can design. <\/p>\n\n\n\n
You\ncan\u2019t use a conductor you can\u2019t process. For the RCA cable, we want as small a\nwire as we can process as this will force the best current coherence through\nthe wire (same current magnitude at all frequencies). The exact skin depth\ncalculation is a tool we use to gain the knowledge<\/em>\nto reduce the wire size in audio cables. At RF, we use it to tell us how much\ncopper to put over a STEEL support structure to maximize RF attenuation. Audio\nis not RF, and the ENTIRE wire is used to move the signal and at ALL frequencies\nconcurrently, not the same issue at all in RF cable design. <\/p>\n\n\n\nRCA cables terminate into a theoretically infinite (47K-120K or there about) input resistor. We say impedance, but it is really as resistive as it can be made at the input op-amp level. Yes, purists will point out that input impedance DROPS some at higher frequencies.<\/p>\n\n\n\n
If\nthe impedance is so high and the current is so low (it looks like an open\ncircuit) just use as small a wire as you can! Well, yes and no. It has to be\nreliably terminated and secure in the end product, and it has to process evenly\nunder tension and not fracture from surface issues.<\/p>\n\n\n\n
A\nreview of the end of process design backs into the initial design requirement.\nCalculations and testing selected a 0.0176\u201d diameter wire for ICONOCLAST. The\nprocess has to handle less than 4-3\/8 pound tension to avoid permanent wire\nstretching. Wire was tested for the process requirement. <\/p>\n\n\n
\n
The\n0.0176\u201d diameter wire (0.0088\u201d radius) is one half the diameters necessary for\none full 18-mil skin depth at audio, so we have significantly improved current\ncoherence through the wire @ 0.0176\u201d diameter wire. Skin depth is FREQUENCY\ndriven for a given material. The smaller the wire the larger the inner current\nmagnitude will be relative to the surface current. We want as good a shot of\nthat as we can get. <\/p>\n\n\n\n
The\nRCA cable\u2019s loop DCR will essentially be the center conductor in an RCA, if it\nis made right, and ICONOCLAST is. The center wire governs attenuation. The\nouter conductor is, in theory, infinitely low impedance so it nearly drops out\nof the loop DCR calculation and leaves the center wire. The length of the cable relative to the input\nimpedance allows a SMALL wire at audio. At least attenuation works in our favor\nat audio as it is a LOG relationship and gets really high very quickly as you\ngo up in frequency. For audio, we can relax a bit on attenuation as it is low\nfor the lengths we use and is in the right frequency range to stay low.\nAttenuation is a passive \u201cdistortion\u201d and is VERY hard to hear over TIME based\ndistortions. <\/p>\n\n\n\n
Dielectric Material(s)<\/strong><\/li><\/ul>\n\n\n\nWe\u2019ve\nalready made a critical choice in our cable. The wire material and size. We\u2019ve\nused good engineering practice to KNOW what the decision will yield. Now, how\nto RETAIN all that the material \/ size wire can provide? That\u2019s easy, just\nstick it in air and find an infinitely low ground potential for our unbalanced\n\/ single ended wire!<\/p>\n\n\n\n
OK,\nthis IDEA is easy. The execution isn\u2019t. I don\u2019t care about speed of the process\nand \/ or costs as I\u2019ve used REASONABLY affordable material as my conductor. We\ncan always go back and break the bank on conductor materials. AIR is free, but\nexpensive to get. Air is by far the best dielectric to have, and especially\nnearest the wire were the influences are the worst on group delay. The closer\nto the wire the dielectric is, the more it influences the overall velocity of\nthe composite structure (wire \/ beading\/ then plastic tube thickness \/ then\nbraid)<\/p>\n\n\n\n
I\ndecided to go the tough route and use air. We can use RF as a HINT at what to\ndo overall. We have used designs called semi-solid core dielectric RF cables.\nThese partially suspend a wire in a tube with a spirally wrapped thread. The\nproblem is that the wire SIZE and the core tube properties aren\u2019t suitable for\naudio frequencies. Even the choice of materials isn\u2019t as important at RF as we\ncan reach a set impedance vector (real + the reactive inductive and capacitive\nparts all added together) by tweaking the thread and tube dimensions.<\/p>\n\n\n\n
3.0 Dielectric geometry<\/strong><\/p>\n\n\n\nThe\naudio signal is very sensitive to the dielectric effects of the plastics near\nit. I chose a specially made beading thread to get the job done.<\/p>\n\n\n\nThe\nabove picture beading around the wire is a glass thread coated in pure\nTEFLON\u00ae. I use a ROUND beading shape\nversus square, as it touches the wire at the tangent points for the very LEAST\neffect nearest the wire. The electromagnetic field sees the entire cross\nsection of the plastics and material between the wire and the inner braid, so I\nuse GLASS thread inside the beading as it is a good dielectric, too. Why is the\nglass there? A solid TEFLON\u00ae bead can\u2019t be processes at this size and keep\nconsistent dimensional linearity. The glass is the true STRENGTH member in the\nbeading, not the plastic. The plastic is to set and hold the shape. The glass\nlets me process the beading at production speeds. <\/p>\n\n\n\n
Why\nTEFLON\u00ae, really? OK, I\u2019ll tell you. It has the lowest dielectric constant of\nany solid plastic. It is TOUGH in thin walls for end product dynamic stability;\nthe bead should STAY round under side-wall pressure. This is a SMALL bead, so I\nneed that toughness. TEFLON\u00ae has high T and E\u2019s (tensile and elongation)\nproperties for process toughness. We don\u2019t have much process room, as I\u2019ve\ncalculated backwards how big this bead would need to be in this design and wire\nsize.<\/p>\n\n\n\n
How\nbig should the conductor be based on a tube ID? There is ONLY one optimum\nasymptotic wire size driven MAX AIR volume (%) based on the tube ID. The ratio\nof the tube ID with the 80% air void to the inner braid surface will determine\nthe capacitance. Maximizing the air content will improve the efficiency of the\ndielectric so the smallest loop area for inductance will also yield the\nsmallest measured capacitance.<\/p>\n\n\n
\n
\n
Here\nis what happens when we CHANGE the wire size;<\/p>\n\n\n\nTube ID (IN)<\/td> Wire Size (IN)<\/td> Air %<\/td><\/tr> 0.070<\/td> 0.014<\/td> 80<\/td><\/tr> 0.098<\/td> 0.020<\/td> 80<\/td><\/tr> 0.123<\/td> 0.022<\/td> 80<\/td><\/tr> 0.150<\/td> 0.030<\/td> 80<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nAs\nthe wire gets bigger or smaller inside a given tube ID, it crowds out the air.\nWe COULD go drastically big in the ID of the tube and wire size (0.150\u201d tube\nID)\u2026but we want to hold INDUCTANCE and signal coherence in check. Inductance is\nthe loop area between the wire and the inner braid, and that needs to be infinitely\nclose, the opposite of capacitance. For a given tube ID size we want the\nmaximum amount of air void and the smallest possible wire to braid distance.\nThis means the conductor wire size has to be as small as you can process, and\nwith the desired capacitance. As the tube ID gets larger, cap will drop but\ninductance will rise, and the opposite with a smaller tube ID. The design\ntarget is 11.5 pF\/foot on the bulk cable to assembly capacitance would be 12.5\npF\/foot. <\/p>\n\n\n\n
Using\ntoo large a wire hurts frequency coherence so we pushed the wire size DOWN\nuntil inductance was moving off spec relative to capacitance. A balance was\nsought between wire size (coherence) and reactive variables (L and C).<\/p>\n\n\n\n
I\ncan do a quick check to see how I\u2019m doing by applying a test ground over a ten\nfoot sample. Using RF frequencies as a \u201cconstant\u201d since the velocity has\nstabilized to an asymptotic maximum, we measure really high VP values, ~ 87%.\nThis is good as it allows me to reference to end capacitance, too. I just treat\nthe cable like an RF cable and work the capacitance backwards from the open \u2013\nshort Impedance; Z = 101670 \/ Cap * VP. This is about 104.6-ohms so capacitance\ncalculates to 11.2 pF\/foot versus a measured value of 11.19 pF\/foot. <\/p>\n\n\n\n
We\nknow from the previous paper that Capacitance and Inductance are FLAT with\nfrequency, and are actually measured at 1 KHz. Our 11.19 pF\/foot bulk cable\nvalue is true at 20Hz-20KHz. Inductance is a low 0.15 uH\/foot through the audio\nband as well. <\/p>\n\n\n
\n
Capacitance <\/strong>@ 1 MHz per ELP 423, Agilent\nE4980A Precision LCR Meter, Belden\u2019s Cap\/Ind Test Fixture<\/p>\n\n\n\n Spec for Cap @ 1 MHz: 12.5 +\/- 1 pF\/ft<\/strong><\/p>\n\n\n\n <\/strong>PDB1610 B24 Cap @ 1 MHz: 11.1947 pF\/ft<\/p>\n\n\n\nCharacteristic Impedance<\/strong> per MIL-DTL-17H (ELP 142) using the included\nequation:<\/p>\n\n\n\nChar. Imp per ELP 142: Imp = 101670\/(C +VP)<\/p>\n\n\n\n
Spec for Impedance: 100 +\/- 5 Ohms<\/strong><\/p>\n\n\n\n PDB1610 B24 Impedance: 104.631 Ohms<\/p>\n\n\n\n
SEMI-SOLID PDB1610 finished RCA \u201cassembly\u201d<\/strong><\/p>\n\n\n\nCAP<\/strong> 12.25\npf\/footIND<\/strong> 0.1450 \u03bcH\/foot <\/p>\n\n\n\nInductance\nisn\u2019t as critical in high impedance leads as current, which is ride time\nlimited by inductive reactance, which is near ZERO, but in my listening test,\ncable with near zero on BOTH L and C attributes sounded best, and a BALANCE\nneeds to be considered. The cable isn\u2019t big or small; it is what it needs to be\nto WORK. The wire size we start with sets this all into motion.<\/p>\n\n\n\n
The\nFEP tube is critical to get right. Special processes are used to keep it\non-sized and ROUND over the beaded center wire. <\/p>\n\n\n\n
Shield material and design considerations<\/strong>.<\/li><\/ul>\n\n\n\nWe\nhave a core tube and know the electricals, so now what? The braid is much more\nimportant than people think, and for a different reason than people think. No,\nit isn\u2019t shielding, either. True, a double 90%+ braid have 90 dB RF shield\nproperties but, I sure hope your equipment isn\u2019t THAT sensitive to RF. Foils\nare much better and more economical for RF than a single 80% braid and the\nshield reaches the 90 dB mark far more cheaply. <\/p>\n\n\n\n
RF\ncables are \u201cshielded\u201d to RF noise and IMMUNE to low frequency nose (outside their\npass band) because the shields have a low resistance to RF, measured as\ntransfer impedance. This is sort of like low DCR at audio frequencies, but\nrelates to how high frequencies work. Audio cables are not RF cables!<\/p>\n\n\n\n
We\nneed to look at how unbalanced circuits work. They SHARE a ground\u2026or do they?\nThey are SUPPOSED to SHARE a ground. They don\u2019t. RCA unbalanced cables use the\nCHASSIS as a ground to the wall outlet or it is floating in some cases but the\nREFERENCE between the grounds is still there. In ALL cases, there is that pesky\nWIRE thing called the SHIELD between the ground points on every piece of RCA\nequipment you use. That wire has RESISTANCE and that resistance creates a\nground potential difference so current starts to flow between the two end grounds.\nE=I*R, remember that? A VOLTAGE is impressed against the center wire and the\nmagnitude of that voltage is the current times the resistance. We can CONTROL\nthe \u201cR\u201d by using TWO 98% copper braids. This is $$$ to do, but it is the RIGHT\nthing to do. <\/p>\n\n\n\n
No,\nthose braids won\u2019t shield MAGNETIC interference. The HUM you hear is more than\nlikely ground loop current through the braids resistance called SIN; Shield\nInduced Noise. The lower the braid DCR is the better the SIN rejection. You\nneed low permeability shield to block low frequency magnetic waves (anything\nbelow about 1 MHz starts to have a considerable B-field bent over E-field).\nGood audio RCA cables ARE NOT going to shield B-fields. They will shield\nE-fields and reduce SIN noise. <\/p>\n\n\n\n
To\nshield magnetic B-fields a MAGNET needs to be able to STICK to the shield. This\nis an indicator that the material is \u201cinfluencing\u201d the magnetic field flux\nlines INTO the metal and OUT OF the air. We can manage the SIN noise with a\ngood ground, but true extraneous magnetic noise is still tough with unbalanced\ncables. Now you know why. It\u2019s the ground system it uses. <\/p>\n\n\n\n
Jacket design and material\nconsiderations<\/strong><\/li><\/ul>\n\n\n\nICONOCLAST\nuses an FEP jacket for some good reasons. FEP is the most chemically inert\nmaterial there is, protecting your cables from chemicals and UV exposure\nthrough those nice picture windows in your house. Lesser plastic material isn\u2019t\nas stable, or inherently flame retardant. Nor can many materials be used in\nthinner walls. <\/p>\n\n\n\n
Plasticizer\nmigration out of the cable, especially near heat, is a real issue in contact\nwith polyester or nylon carpet that would love to be the same color as your\ncable laying on it! My previous cables were. \nFEP does not have this issue and will look nice for decades to come.\nYes, it costs some more but these cables are an investment into the future and\ncan follow your system several steps above where you may be now. Based on\ndurability, stability and inertness to solvents, FEP is the best choice for the\nlong haul. <\/p>\n\n\n
\n
RCA SUMMARY<\/strong> – Knowing that RCA cables\naren\u2019t as \u201cshielded\u201d at audio as we think, what can we do about that? If you\ndon\u2019t have the problem, you\u2019re good to go! RCA is a great sounding cable by\nfundamental electromagnetic design. This is why it was created. It does have\nmagnetic noise immunity issues, though. There is no magic to good cables; it is\nadherence to strict design rules that also encompass those \u201cmagic\u201d tertiary\nvariables called wire science. The same\ndesign adjusted for a new material\u2019s skin depth properties can be made to the\nsame \u201cratio\u201d and match the electricals with differing wire. The layers of the onion and their thickness\ncan be altered (L and C values) depending on what is most audible. Tests won\u2019t\ntell you that, this comes from design experience. This does NOT mean that either L or C can be\nthrown to the wind. Both L and C cause\nTIME based distortions and neither is welcome in good cable. <\/p>\n\n\n\nThen\nthere is the next cable I\u2019m going to talk about that does exactly that, except\nit is far, far harder to make as good as an RCA electrically. It is called the\nXLR cable. <\/p>\n","protected":false},"excerpt":{"rendered":"
In a previous paper I covered several issues that create signal distortion in audio cables. The most demanding variables involve the TIME related distortions that the ear is most sensitive to. Consideration must be made during cable design to mitigate the TIME based issues through the audio band. The following…<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,10,11],"tags":[],"class_list":["post-81","post","type-post","status-publish","format-standard","hentry","category-rca-cables","category-1st-generation-single-ended-rca-cables","category-2nd-generation-single-ended-rca-cables"],"_links":{"self":[{"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/posts\/81","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/comments?post=81"}],"version-history":[{"count":0,"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/posts\/81\/revisions"}],"wp:attachment":[{"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/media?parent=81"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/categories?post=81"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iconoclastcable.com\/blog\/wp-json\/wp\/v2\/tags?post=81"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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