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My partnership in Stereovox faltered by 2005. In 2006 it was over. It's a long sad disappointing story. Essentially I was relegated to not only having to start over but deal with about $60.000 in Stereovox debt which I agreed to assume as both our debt just to free myself from a destructive untenable irreparable situation. There was a period of about 3 years where I'd agreed to 'tithe' a percentage of my gross sales in exchange for using the Stereovox name. I eventually dropped this and created the Stereolab brand instead. This more or less coincided with the great economic meltdown of 2008. Things weren’t looking too hot.   
Stereovox SEI-600II

My family and I left our live/work loft in midtown Atlanta for less expensive suburbia. Now I built my workshop into the side of the house. My dealers were disappearing as were my distributors. This meant my customers and living did too. This type of thing is at the root of phrases like 'necessity is the mother of invention'. Serious thought had to go into plans for my future. That’s when I established Black Cat Cable to reach customers directly via a hybrid program that'd not eliminate dealers and distributors provided they accepted truncated margins. It got me around the gatekeepers of dealers and distributors who had the customers I still needed to reach but who represented other cable lines to give me the cold shoulder.


It was a risky choice but my back was against a wall. I had a family to feed and by October 2009 we'd increased ours with the birth of my daughter Josephine. As you know we started Veloce in 2010 and did our giant-slaying best to make a case for ourselves in the market. Thankfully Veloce was well received and sold at a reasonably good pace. This was as good a digital cable as I'd ever designed up to that point and I was eager to share it as far and wide as possible.


Starting 2009 I began developing in-house processes for insulation and shielding. This resulted in Aeron™ to allow me use of pure unbleached continuous-filament DuPont Teflon yarns in a no-heat chemical-free process for a dielectric that incorporates quite a bit of air. Without having to resort to chemical foaming this very green process allows me to create very high-velocity dielectrics without having to pay a pound or two of flesh to subcontractors who don’t have this ability in the first place.

Black Cat Cable LectraLine

Owning production means and being able to produce at will from raw materials meant that my production costs went down significantly. That coupled with a hybrid direct-price model coupled with very low overhead (just me in my home workshop) meant that Black Cat Cable could make and sell cables which otherwise might end up costing a few thousands from the audiophile cable industry at large. From being a designer subcontracting manufacturing of his raw cable designs to a small but precise military/aerospace contractor in upstate NY to assemble them in-house by a small team of employees to being the designer and manufacturer and chief bottle washer, my business paradigm had changed dramatically. My work load now is extremely time intensive. By the time I got around to a USB cable it was simply a matter of finally having the time to do it.

And I  don’t think of myself as a self-proclaimed expert on digital hifi cables. I’ve known real experts whom I’ve been privileged to learn from. I couldn't much more than shine their shoes. I’m grateful they took me under their wings and gave me the kind of practical versus theoretical foundation few people get. I remember when Illuminati was still young, perhaps 1994-5. I was in my late 20s. I was visiting one of my mentors at the subcontractor who assembled and tested the Illuminati D-60 and DX-50. I walked around the compound with the owner, an older gentleman of decidedly Southern gentility. We talked shop and I asked as many questions as I could. He was an extraordinary man who'd left his job at E-Systems (now part of Raytheon) to start this company on Florida's west coast. The knowledge he took with him in that prodigious brain of his was so valuable that E-Systems had to come to him again to get certain things done. I confessed to being pretty intimidated by how much I didn’t know. Sure I was the son of a Master Electrician. I'd been brought up in the family business from when I was 8 or 10. Electricity and wire were in my DNA. But my education of signal transmission began with these microwave and aerospace guys, first with my original partners John and Rose back in Coral Springs and then with this fellow. In that moment of confession he put his hand on my shoulder and told me that I knew more about some of this stuff than the guys he'd get fresh from university. Sure he was blowing sunshine up my ass and I appreciated it and knew not to let it get to my head...but he also told me something else I'll never forget.
Close-up of Aeron™ weave around conductor
He said that once he got these fellows from university he had to start deprogramming them from book theory and teach them about practical design involving lots of iterative modeling and testing - basically elbow grease and a willingness to diverge from theory when needed to ensure that something worked well. To illustrate this he took me into one section of the building. Stacked against the wall were a series of doodads. My recollection is a stack about 2-3' high, about 10 or twelve feet long and each about 8-10" long x maybe 2-3" square. And he goes, "do you know what those are? Variable air-core capacitors for fighter jets." He points to the one on the bottom left. "That was designed by the book and stricty to theory." He points to the one top right. "That's the one which actually does what it’s supposed to do." No wonder E-Systems/Raytheon needed him. That man was an expert. I'm just a guy whose designs stuff for hifi.

Chris' inspiration for his top reference Tombo line where tombo is Japanese for dragonfly
About my first USB cable failure, I wanted to try something I'd been messing with, an iteration of my InterPole conductor geometry with some other materials involved for noise suppression. I imagined that over such a short distance an impedance mismatch would be mostly invisible to the interface. I'd rack up some advantages of this particular iteration of 4 polarities expressed over 16 conductors interwoven in a noise-suppressing media to address the interface. Not. I'd talked with Gordon about this. He'd told me to check file transfer rates between ordinary stock wires and anything I might be trying using an external HD and 1GB file. I tried thinking at worst I'd clock the same transfer rate back and forth as the ordinary Belkin cable. My heart sank when the HD didn’t even show up on the desktop. Sobering. Going back to basics meant cracking open the USB 2.0 spec document.
Interpole™ multi-pole conductor
S/PDIF and USB are very different interfaces, protocols, standards and demands. My fairly simple fix isn't a common mode filter as others are using. I'm also not planning on using any at the moment. There’s this idea that the +5vdc power line is somehow infecting the data pair with computer noise whilst these wires make their way to the DAC.


But that begs the question: wouldn’t this noise be present in even stronger more unrestrained form right inside the computer where all these lines originate? Of course it would. So to me at least this seems to be partially erroneous thinking about noise on the power line or ground or data pair or drain wire or shield. If there's any noise in the cable at all, it came from the computer to begin with. That's where all these 'lines' intermingle in the same cess pool of RF.


About square-wave digital transmissions, bandwidth and speed, they interlink. A square wave is a series of superimposed sine waves i.e. a fundamental with a bunch of odd-order harmonics. For example a 1kHz square wave would be a 1kHz sine wave + 3kHz sine, 5kHz, 7kHz, 9Khz, 11kHz etc. The required bandwidth is broader than what accounts for just the fundamental since you must consider a host of odd-order harmonics.


As frequencies rise it can get very demanding very fast. On the other hand we’re essentially talking asynchronous operation thanks to the pioneering work Gordon did with the Wavelength DACs. This is very different from S/PDIF which derives its clock from the transport and combines it in a bi-phase combo code called a 'Manchester code'. And is anyone even bothering with adaptive-mode USB DACs any longer? One would think that asynchronous operation almost ensures a cable wouldn’t matter very much. Ironically the opposite seems to be the case at least judging by reviews and forums I’ve read and by feedback I’ve gotten from our beta testers.

Bandwidth for really high-frequency performance in a signal cable is typically determined by the tightness of the impedance characteristic (tolerance over the cable length) as it relates to matching the load impedance of the receiving device and also to the connector's quality and impedance characteristics. This assumes average L&C of course and good leakage control. As frequencies rise and wavelengths shrink, these things become more and more critical to maintain precisely. As cable lengths begin to approach certain fractions of the signal wavelength starting at ~1/10th wavelength, we must begin to model potential transmission-line effects. One of those is VSWR as the ratio of reflected signal (due to impedance mismatches for instance) to incident signal. When we generally talk of reflections we’re typically referencing standing waves caused by impedance mismatches somewhere along a transmission line. This gave rise to time domain reflectometry as a means of detecting where impedance mismatches occur along fairly long transmission lines.
Designing such cables involves all the usual subjects of geometry, conductors, dielectric, connector & Co. But in a way this oversimplifies and totemizes the issue. It’s not so much that the whole is greater than the sum of its parts. It's that addressing this linearly doesn’t necessarily reveal how some of these things interact with each other and with the signal and with the actual device. The whole as we see it extends to the whole of the digital system, not just the cable as a variable or the cable's individual parameters. Such abstractions do try to understand aspects but capacitance, inductance, resistance, impedance, velocity etc. don’t exist in a vacuum.


They're aspects of a systemic whole which extends to internal portions of the devices which cables connect. High-speed USB 2.0 operates at 480Mbps, 240MHz@400mv p-p. When looking at the 240MHz spec remember fundamentals and harmonics. These aren’t sine waves. The rise-time switching at that rate is probably in the Gigahertz range. As far as I know the interface isn’t going to switch faster than 480Mbps/240MHz no matter what the software is doing. The transfer rate is dictated by the hardware standard. I don’t think anyone works at 241MHz.		  
QuieTex™ is our trade name for a process that covers a small range of textile weaving materials like highly conductive carbon fiber, carbon-content multi-filament textiles,  carbon-residual teflon and metal conductors to create a noise-blocking shield that works to absorb spurious RF and keep it from infecting the signal traveling within the cable. QuieTex also interacts with the electromagnetic and electrostatic fields generated by current and voltage carrying electrical wires.


For USB cable the standard is a differential impedance of 90Ω so a terminating impedance for each of the data lines becomes 45Ω. In Chapter 7 of the USB 2.0 spec we have this reference:"The DC resistance from D+ or D- to the device ground is required to be 45Ω ±10% when measured without a load; and the differential output voltage measured across the lines (in either the J or K state) must be ±400mV ±10% when D+ and D- are terminated with precision 45Ω resistors to ground."
On a kind of Trøn USB, I know what I'll do for the Master Reference. This has been prototyped already. I just have to hunker down, get the right materials onto the right bobbins and payoffs and run it. I hoped for Thanksgiving but now it looks like Christmas at the earliest. It’s not easy being a one-man show. But I do like the control it affords me.


So far I don’t have plans for a Trøn-level USB cable but as always I’ll be experimenting. For now I’ve got the Silverstar. I’m happy with it and as with all my Black Cat Cable products, I hope folks will see it for what it's intended to be: higher performance than its money will buy anywhere else and surprisingly high performance even when matched against the heavy hitters and favorites. The 24" model is for the desktop and was added by request from my buddy Jack Wu at Woo Audio. It's $99 with a 60-day money-back guarantee for our US-based Stereomatic web store customers. I’m hoping that people will try it and discover there’s probably no better deal available anywhere. Then I hope they'll spread the word. -
Chris Sommovigo