Interview – Nordost’s Bjorn Bengtsson and Johann Graham and Advance Audio’s Michael Di Meglio
Edgar Kramer: Thank you for this interview. As far as home audio, Nordost offers four ranges with multiple tiers of cabling for all purposes. We notice that as you escalate up the product ladder the conductor material (silver plated solid core copper) is the same while the general geometry of the cables remains similar. What are the changes from model to model then?
Bjorn Bengtsson: Yeah, well, we do have a better copper, and we do have varieties of the Teflon, or the FEP. It's, if we were buying the raw material from DuPont, it would be Teflon but that's, it's FEP, for the record. We have different degrees of purity of that, and mainly, in terms of the manufacturing process, it is just a matter of making things more thorough. We polish the surface of our conductors, we put it through ultrasonic bath, for cleaning.
When we extrude the Teflon, or when we wind the Teflon thread for the monofilament construction, you can do that in various speeds, which will give you various results, in terms of how thorough that is. I don't have the recent figures, but just to give you an indication, the Valhalla One took, with all these steps, and operations, it was calculated to be about eight hours for a meter, and that is just one meter, not a meter pair, but just one meter. The time is just a very large cost factor. We can polish down the surfaces, the tolerances of the conductor, say, within ±2 microns of a millimetre, so the tolerance is just extreme, and as you climb the ladder, they're becoming more and more extreme, or tighter.
That is a large part of the increment in price, and obviously, the more conductors you use, the harder it is to maintain these tolerances with individual conductors in the cable geometry, so it's just trickier and trickier, and takes a longer time to do that. Still, we're using the same core material, which is a real benefit, because you would have increments of performance in a very vertical pattern. It's not one of those where you spread off, "Oh, there's the classical cable," and, "Oh, here is the jazz cable," it is just on the same parameters, we're increasing in all the areas where we excel: imaging, spacing, spatial information, detail, punchy bass. You need a lot of metal to get into that to transport the current, and it's just harder and harder to do the more you add, so…
EK: Have the engineers at Nordost brought their experience from other high-tech industries (eg. telecommunications) or are they strictly audio engineers?
BB: That's a wide mix. I’m having a part in the R&D group. My background is mechanical engineering. One of the engineers is a doctor in chemistry, so there is various backgrounds. We think that to be one of our strengths that we can actually fit in a lot of different angles and experience. The production engineer, production leader, has a solid background in connector engineering, so he's been working for big projects in other areas.
EK: Does Nordost design connectors, as well, or do you use generic ones?
BB: For the top-range products, we have our own connectors. They are designed and produced by Nordost and are called HOLO:PLUG which is our construction through and through. We do have, at the very entry-level products, OEM plugs like Neutrik, but some of those we actually modify ourselves and call it our Moonglo connectors. But all our products are manufactured in the USA.
EK: Have the lessons learnt in making the first gen Valhalla and then the Odin, after that, made their way to the more cost effective cable offerings?
BB: For Valhalla, for instance, that's just a perfect example because that's what has happened. We introduced the Valhalla and we had the greatest technology, the mono-filament, at the time that we could possibly get our hands on and we just fiddled around until we had a really good product. And of course, the two questions that comes out when you present that: When is this going to be cheaper? And, when will you have something that is more expensive? So that comes out. You just trickle down that. As we were talking about earlier, what we can do is we can use lesser conductors, we can speed up the manufacturing process, and you will compromise. And it is in that, when we introduced what we call the Norse Series that was just a matter of trickling down into different layers of compromise, basically. It's an FEP thread that we wind around the conductor as a filament. It fills out the gap and creates a virtual air gap.
EK: It must be very difficult to terminate…
BB: Very time consuming. We use thermal strippers because, you remember that I mentioned that we polish the surface and ultrasonically clean it, so if you were to strip that with the traditional mechanical stripping tool, you would just ruin the surface. So our thermal strippers have been designed specifically for the way our cables look. There are different strippers for different cable products, and so on. Here's the thing, we make everything in our facilities from scratch. We even pull the copper through it, you know we draw the copper in our place.
EK: And is it Australian copper? We've got the best copper in the world.
BB: So I've heard. And I actually don't know. I should investigate.
Michael Di Meglio: Can I ask a question that a few people have actually asked? Bi-wiring. Can you talk about that a little bit?
BB: Bi-wiring is, basically, a measure or something that a speaker designer does in order to make his product cheaper because you don't have to have an as advanced network for that. So you actually just forward the problem or push it aside. We have created a good set of jumpers instead. So if you have bi-wire terminals on your speaker – bi-wire not bi-amping – at your amplifier the dual sets of connectors will be put together on the inside of the chassis of the amplifier, right? What you do is that you would forward, or transport, a set of frequencies that you've joined together on the inside of the amplifier. So you will have all that length of transportation to introduce phase shifting because you're dividing the frequencies, whereas you would want them to come together as quickly as possible in order to eliminate any of those phase problems. So the long transportation should be done with the frequencies together. That's why we concentrate on making really, really good jumpers. The long transportation back to the amplifier should be done with the frequencies united, as opposed to have them apart, and then put them together on the amplifier end.
EK: Is this also related to the skin effect?
BB: Yeah, skin effect is a totally different thing, actually. That is depending on how the signal is actually constructed, so you will have a total different value of skin effect, or 100% penetration of frequencies for, let’s say, what is coming out of a CD player, compared to what is coming out of an amplifier. The skin effect that would occur from the output of a CD player is totally different from when it would appear in a speaker cable construction. There is a measurement of having 100% penetration of the frequencies, of all frequencies that can reach all the way through to the centre, that's 100% penetration. As soon as it starts to deviate from that, when the full set of frequencies cannot penetrate to the centre of the conductor, that's when the skin effect starts. The frequency starts to separate towards the skin, of the conductor. That is what the skin effect is. That's why we do multiples of conductors instead of having larger conductors. You keep 100% penetration, but you want more metal so you have to add conductors.
EK: Seeing that the conductors aren’t single copper flat coil multiples, why are Nordost speaker cables flat?
BB: Yeah, in terms of speaker cables, it's purely from a… basically, dealing with the problem of inductance. Inductance will introduce a filter effect in your transportation of the signal. Reversed, if you were to produce or manufacture a transformer, you would want the inductance. That is what you create it from, so you create the spool, or like if you have a cartridge moving coil, you create that, so you want inductance. That is what you work with. Whereas it becomes a big filter affect for a cable. Pretty much with any given amount of conductors, the lowest amount of inductance would be achieved in two dimensions, not three, so that's why they're flat. And then there is a side effect of that, they’re easy to deal with, you can lay them under the carpets, and so on.
EK: In a high-end system, and when it comes to Nordost cables in particular, which cable type do you think makes the most significant performance improvement? Is it the speaker cable or interconnect or…?
BB: The power cord, we always recommend to start with. The functionality of electronics will be determined by the quality of the power that it can be provided with. If we have not done that, secured that the ultimate performance is achieved for the electronics, we will have a lesser quality signal leaving it coming through the interconnects or the speaker cables, so it pretty much all starts with the power cords.
EK: Some people say, well, you've got hundreds of meters of AC cable coming into your home, how can the last meter make a difference?
BB: What I normally say is it's not the last, it's the first. The power supply, electricity is just another energy source, basically, so it will spread evenly over all the conductors that you have. But the power supply will create an incentive for the electricity to work with it. It's like your body, your body is a good incentive to have electricity move towards you. That's why you get a certain reaction if you stuck your finger in the power point. It comes your way. The power supply pretty much does the same. It creates a really good incentive. The better the power supply, the more of the transients, and the more of the current draw you can have from the grid. That is what we're just providing for. We're providing for a better circumstance for the power supply to operate accurately. So it's the first. That's the most important.
EK: As far as digital cables, if digital data is re-clocked to 100% accuracy, how could there possibly be any sonic differences between USB or SP-DIF cables?
BB: When it comes to digital data, it’s 1s and 0s, power on or off. When you use a player to play and forward the signal through the USB protocol, or using that USB protocol to a DAC, it has to obey the laws of physics, again, and one is the power on. And there is a very limited time of capture to get that signal to have it registered as a 1. If it's not registered as a 1, it's a 0, which is wrong. There is no in-between. Either it's right, or it's wrong. If you get it right, it's good. If you get it wrong, it's bad.
What we can do with very low capacitance cables, the USB and the HDMI protocols pretty much operate in the same way, so if we have very low capacitance, we can increase on the rise-time significantly, providing for much larger area for that tiny capture to happen. Because that's the clock again. The clock, you have a bit stream, or a data stream, the clock defines when the capture is. If the data stream is off, even though the clock may be 100%, the capture is not exactly where the capture should be. If we can improve, just giving a wider area of the allowance for a good capture, we're just providing for better circumstances to get it right.
EK: If that error's there in timing, I guess that's a form of jitter?
BB: Yeah, yeah, that would be it.
EK: So are you saying the cable can introduce jitter?
BB: Well cables can. It's not actually the cable that does the jitter, but it can worsen it, or it can lessen it. If the data stream is off compared to the clock, if you have a poor cable, you will be very off. You will have all kinds of misreading and error corrections.
EK: Were there challenging aspects to making USB, ethernet and HDMI cables using Nordost’s design philosophies in order to meet industry standards?
BB: No, the standards, with our technologies, are very easy. As you may notice, we have USB cables that are quite significantly longer than what you would find in a computer store. Digital data needs ultra-fast times. Within a certain amount of time, if it doesn't, it just disconnects. There's nobody on the other end, so I'll just hang up, basically. In the standard cable construction, that would be around five meters. That's why you don't find longer USB cables than five meters in a store, whereas we can do up to 12 or so. It's significantly longer because we get that, the cable has that propagation delay. It's just much quicker. Within the same time limit, we can have twice as much cable as a computer can, and we still get the return. We use a Twinax design, not twisted pairs, with both USB and HDMI.
EK: Has Nordost experimented at all with impedance or other componentry matching boxes/networks, like MIT and Transparent Audio do?
BB: Not really experimented with. We know what is going on. In our book, it is more a network, as in actually altering the signal, or making a frequency adjustment to the signal, which is really what we just try to stay away from. It's pretty much the other side of what we do. Not saying that anything is wrong or right, it's just not the way we do.
EK: What's Nordost's take on cable burn-in and what do you think is happening there?
BB: It's an important part. Since we have for quite some time been building a burn-in or a break-in device, so yes, it makes a huge difference. Typically, people think that electrons actually, physically flow through, whereas they don't, really. It's a chain reaction of how they interact. So with the burn-in process we can clear out the paths of the energy. One factor would be that you have a large current, or a large frequency spectrum, which is like a general burn-in, and that's what we do with our burn-in device, the Vidar. Then there is a specific burning process that happens in every individual system because there is that type of power supply with that type of amplifier, this and that, so on and ... We can do a significant amount of burn-in or break-in with our device, but then there's is always a last piece that has to go within that particular system.
EK: So for people that use Nordost cables and don't use the burning device, what is that period of burn-in, in your experience, is it 100 hours, is it 200 hours, is it 50 hours? And what happens within that time?
BB: It depends a bit on how powerful the signal. Normally, a digital or a phono cable, the phono cable are the worst ones, they take they take the longest time. Digital cable takes a little less time, but still a long time. Speaker cables are pretty much quick to do because you put a lot of current through them.
EK: Do you suggest a formula of percentage of spend on cables, in terms of your system. You know, some people like formulas… 25% on cables and the rest, 75, on the system. What do you suggest?
BB: The cables should be considered components. Take a CD player. You need a power cord and you need a set of interconnects to connect to that, so there is where you should start to look at your ratio, or how much you invest in the cable. It should be judged by experience, by listening. Some constructions benefit hugely from having a really good interconnector, or a particular power cord, or whatever. It should be judged from that, not from a preset ratio. It’s system and component specific. One component at a time.
EK: We touched on this earlier, how important does Nordost consider the connector to be?
BB: Oh, very important. We really do consider our cables from connector tip to connector tip to be the product. To us, it is as strange when people come and say, well I'd like to have a Furutech connector on my set of Valhalla… well, do you call up Wilson Audio and say I want a specific driver in my speaker? No. This is the product. So, yeah, we do consider the connectors to be a very important and integral part of the overall product design.
EK: So there’s quite a bit of listening happening in the design of the entire cable, right?
BB: We have a listening room, and we have a lot of gear in that, which we go through. But we also have a group of people that listen to the products, so there’s not a single reference system nor a single set of ears. That gives us a lot of answers. We want to make a universal product that would work in so many different environments, so many different compositions of electronics, speakers, and whatnot. Therefore, we really strive to have that variety of testing before it becomes a product.
EK: There are more cable brands than you can even attempt to count. In your view, what differentiates Nordost from the throngs of cable manufacturers? I mean, the configuration is quite different but is there anything else?
BB: I said in the beginning there, we have a distinct path for following our goals, or what we want to pursue. The foundation is the solid core construction, the extruded FEP and in the higher ranges, we use air insulation, mono-filament construction, and even further up we have our own connectors, and so on. I would say we have a very distinct path of a non-filtering technology, if I may say. We try to mess with the signal as little as possible, that's really our goal. We talked about the propagation delay. That's a good measurement, it’s a good indication of whether the product absorbs energy, or not. If you you're getting close to 98% of the speed of light, like the Odin speaker cable, it’s actually the closest product to a super conductor, in room temperature, that you can get. Very, very little energy is lost in the transportation. And that is one thing that we consider to be very, very good. We just want that energy to go from one point to another without losses.
EK: What led Nordost to go from strictly cable making to the production of the isolation and the QRT AC products?
BB: Well, we got in contact with a company called QRT and we started a corporation with them. One thing led to another and all of a sudden we owned that company, too. Then we started designing the products ourselves. We learned as we grew and we understood that we could implement a lot of our thinking into that arena, or that area of things. A lot of the things we do with the cables make a lot of a sense in that scene too.
EK: How do the Qx, QK1 and Qv2 AC products work?
BB: Basically, we're working with various electromagnetic fields in order to either repel interference or disturbance, or to move it out of certain areas, which is allowing us to use a very unconventional approach to things. The effect is like a filter, but it's not a filter that is in line with the signal, it is parallel. So we can either repel or move distortion from the outside parallel to the energy field electricity. They have to be plugged in to the same circuit as the system.
EK: What are the strongest markets for Nordost around the world and how has Australia placed within that?
Johann Graham: It's going too strong (laughing). Australia has a fairly new distributorship but going very strongly. Hong Kong and China are our largest markets, currently. And some of the Scandinavian markets, Norway, are very strong. France is very strong in Europe. And obviously the US.
BB: Hong Kong and Norway, in that order, have the strongest Hi-Fi tradition per capita. And Norway is very cold… conducive conditions for audiophiles and great music listening.
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