Dielectrics: a discussion on materials
The cat may be already out of the bag on this one for some folks, A few folks on these forums have been made privy to this product and I'm excited to say, there are likely quite a few reviews incoming.
The TLDR: I am about to release a product that utilizes a tech that is brand new. I have been working on it for going on 2 years now (including a patent pending currently) and am on the verge of releasing the first product amongst many to utilize this tech VERY SOON.
But before I do, I wanted to chat a bit about the journey that brought me here.
One of the myriad things about cable design that I am fascinated with is dielectrics. It comes up surprisingly infrequently in this forum and I thought to myself this is one of those things that I feel warrants discussion on my thought process for the topic.
Types of dielectrics are numerous. From your standard fare teflon and vinyl to your oddball variety such as cotton and nylon. Breaking down a few things to a somewhat oversimplified explanation (not that most of you folks need one!), a dielectric is an insulating layer that serves to transmit electric forces without conduction. In other words, it is what protects the bare conductor from unintended conduction.
While on the surface this would appear to be straight forward, we as audiophiles know better. Different dielectrics result in drastically different sound quality and efficacy. The reasons are numerous, from permittivity (aka K value) to vibrational dampening coefficient, to how effectively a dielectric can slow the oxidation process.
This is my outline on what I consider to be effective and what I consider to be improper dielectrics. Below is a brief explanation of these top three factors and the materials/techniques that should be highlighted.Vibrational damenping:
Ideally, a dielectric would allow a wire to move about freely, but not ‘ring’. If a wire is being over dampened the result is a loss of the vivacious nature of a signal. A great shorthand way to think of it is dampening vibrational nuance makes heat. If vibrational nuance is dampened too heavily, electrical signal is being converted to heat. This is commonly what I hear with cables that utilize a lot of heavy material. A certain loss of low level detail. It isn't even something one would notice if you weren't aware it was there in the first place. Teflon
One of the factors I consider to be of utmost importance is the degree to which a dielectric dampens vibration. Heavy materials such as teflon and even foamed teflon while having excellent dielectric properties (a K value around 2) they tend to be heavy and over dampen the signal conductor. This is because teflon is very dense and relatively stiff. One thing to remember is a dielectric is in constant contact with the signal wire and thus its effect can be drastic over distance. The sonic signature of teflon is one that retains great bass and treble clarity, however it is often done at the cost of loss of midrange texture and detail. This is the result of over dampening.
There are several ways to mitigate this, such as utilizing the thinnest teflon dielectric as possible (as with Breathe C, Quiescence C and Ember USB) that said, it is often the case that heavy stiff teflon is the norm. And even if one mitigates this issue by using less dielectric the issue does not go away completely.On Oxidation:Cotton
Cotton is one of those materials I have a love/hate relationship with. It’s true, I love to hate cotton.
Not because it’s a bad dielectric, but that cotton is one of the most inferior materials used in high end cables today. I want to be clear, I'm specifically discussing cotton over bare wire, not cotton utilized external to another dielectric material. First let’s chat about what makes cotton superb. Cotton being a woven material and lightweight has excellent dampening properties. Cotton also has a superb K value somewhere around 1.6. Sonically speaking, it is apparent why Audiophiles love it so much. The sound quality is often excellent. However this sound quality may not be long lived.
One of the parameters that may not be immediately apparent is that because cotton is 100% permeable
as a material, oxidation is a major problem. Any copper wire that is exposed to air will oxidize over time and when there’s 100% permeability the internal wire is at the mercy of the external environment. God save those who live in humid areas, your cotton clad cables are doomed to slowly losing their vivacious sound quality the longer you run signal through them. The same is true for any situation where wire is exposed to air. Which means potentially teflon/air tube dielectrics, braided nylon dielectric, wax etc. On Teflon Matrix dielectrics:
A few ultra high end companies take the somewhat insane step of creating a network of Air/Teflon thread dielectrics. I have been told by the manufacturers of such designs that these cables can take upwards of 2-3 months to make. And the price they command is proportional to the labor involved. These networks cleverly dampen the cable with ultra thin teflon thread in a larger tube matrixes. The result is an astounding air to dielectric ratio of 98.9%. That’s right, only 1.1% of the wire is making physical contact with the dielectric. As stated previously, this is a remarkable result that requires engineering beyond what most would consider ‘reasonable’. For the purposes of this article, this will be considered the benchmark of what is currently the state of the art. So, In a nutshell:
Teflon dielectrics are too heavy, but easy enough to implement. Effective if implemented properly.
Cotton dielectrics are an oxidation nightmare, but very good vibrational dampening features. Effective but potentially terrible for oxidation. I would say the problem is bad enough that I would never consider utilizing cotton in any of my designs period.
Teflon thread/Air dielectrics require exotic and labor intensive builds that break the scale on cost/performance ratio, that said, they represent the pinnacle of current dielectric technology. My take:
I have contemplated all of this and more for several years. Long before Hapa Audio was even a twinkle in my eye! I wanted to consider all of the above and approach the problem from a different angle. One that put me on a journey that I am just now able to discuss. I look forward to sharing this with you very soon.
All the best,