Inside Track: IsoTek’s Keith Martin

Posted on 11th October, 2020

Inside Track: IsoTek’s Keith Martin

David Price talks to IsoTek's founder and chief designer about the importance of clean mains power, and his company's approach to it…

Keith Martin is not the type to dodge a challenge. One of the hi-fi industry's most driven and thoughtful characters, I get the feeling that IsoTek's rise would not have happened if he'd been a 'low energy' type of guy. A great many hi-fi show-goers will likely have seen him demonstrating his range of power conditioners and mains regenerators over the past two decades or so – all over the world. Indeed, he seems to tour more than a seventies rock supergroup!

StereoNET interviews Keith Martin of IsoTek

Keith Martin

“IsoTek was born out of a desire to make things better, and do it in a way that others weren't,” says Keith. “It took about a year or more before we even came to market with one product. That was at the end of the nineteen nineties, and the first product we introduced was in 2001. It was called the Substation, basically a modular space frame design. It was born out of an intent to do things right and be scientifically driven, but we didn't really think about it from a commercial perspective – and it was complex both to sell and for the end-user to specify.”

StereoNET interviews Keith Martin of IsoTek

IsoTek HQ

“Our name came from 'isolation technology', and our mission was to reduce mains noise going into hi-fi products, to improve sound. Right from the start, we were thinking in terms of modules for each mains outlet to reduce cross-contamination from one hi-fi component to another. From the Substation, we created the Minisub – which was like a miniature Substation with a PCB that had six individual power cleaning circuits on it. It was easier to understand, a more effective product that could be stocked by dealers and sold in a simpler way. Yet it still retained our core thinking, and was affordable at around £700, back in the day. Minisub was phased out a decade ago and replaced by Aquarius, which is a far better design and perhaps our most award-winning product to date.”

StereoNET interviews Keith Martin of IsoTek

IsoTek Aquarius EVO3

It wasn't plain sailing for Keith, his problem being that he was selling into a practically non-existent market at that time. For example, speaker makers launching new products don't first have to make a case for the very existence of loudspeakers – people already know why they need them. With IsoTek, however, the brand had to persuade people of its primary reason for being. “Power conditioning and cleaning were considered a voodoo art back then”, explains Keith. “We had to go out there and say these are the facts, this is what we do, and this is why we do it this way. We solved the problems in the best manner we could.”

Key to IsoTek's approach has been its live demonstrations. “We will show you and let you hear for yourself whether our products work”, says Keith. “Of course, we are not the first company in the world to do A-B demonstrations like that! Linn products, for example, was very famous for doing its 'tune dem'. We do it on a power level, letting people hear music with standard mains power, and then put our own products in and explain why we're doing it.”

StereoNET interviews Keith Martin of IsoTek

It's interesting that Keith references Linn's Ivor Tiefenbrun. Veteran audiophiles will remember his hugely popular hi-fi show demos in the seventies and eighties. He always spoke in terms of the primacy of the source component in the system, citing that old computer industry maxim “garbage in, garbage out” to show that your system can only sound as good as its source. For example, brilliant loudspeakers won't improve the signal coming from a mediocre turntable. Keith expands on this…

“We believe that power really is the first input – in a way, it is the source – so mains quality will have a dramatic effect. And this is measurable on connected electronics. It's not new – for example, life support systems in hospitals would have a dedicated line with back up, in case anything happens to the mains supply. One specific example is DB Technology in Cambridge, which is a precision component testing company. It uses power cleaning devices for consistency and accuracy of the measured results they undertake. I have the greatest respect for Ivor because he turned the industry on its head. Before him, everyone thought speakers determined the sound of a system. Now though, we know differently…”

StereoNET interviews Keith Martin of IsoTek

StereoNET's David Price and Keith Martin

“I think since then we've added two more overlooked factors”, adds Keith. “First is room acoustics, as people forget what a profound effect this has. Second is power, which is equally fundamental. Getting really good, correct power into an audio system is vital. These are the two forgotten members of the band. I mean, consider the poor drummer at the back there, he's rarely remembered or recognised mostly – unless he's part of Fleetwood Mac, I guess! These are the two areas that normally a hi-fi enthusiast comes to last of all and perhaps, they should have come to them first.”

Keith says that making a case for clean mains power wasn't so much a road that's hard to travel on, as an overgrown footpath that's hardly ever been used. “You could barely see where to walk! In the early days, I found it very difficult to be taken seriously. Setting up good international distribution was particularly tough. Everyone accepts the need for a decent CD player or streamer, but power cleaning? Lots of people said they didn't need it. Our argument was that you absolutely do. That's why I've been travelling so much for the past fifteen years, banging the drum about why power matters. It's not for the faint of heart, I can tell you.”


IsoTek's fundamental approach is to reduce two types of noise from AC mains, Keith tells me. “I'll go with large brush strokes here. You've got differential mode noise and common mode noise. The former sets up equal and opposite noise on both the live and the neutral feeds of the mains. It's generally created by anything with an electrical power supply, in other words, all the things you have connected into all your home wall sockets will be creating this form of distortion. Of course, it varies from place to place in degree; those living in city centres will experience more than those in a country village. It tends to be time-sensitive, which is why many people think their hi-fi sounds better late at night. For example, if you're living near an industrial estate, it's going to be less of a problem on a Sunday evening than Monday morning, because none of those machines are running…”

StereoNET interviews Keith Martin of IsoTek

IsoTek SuperNova EVO3

Keith explains that common-mode noise, typically from radio sources creates equal in phase noise on both the live and neutral. “It comes into your system because a cable is basically an antenna”, he says. “We also deal with spike protection as well and have a unique protection system which acts a little like ABS braking in cars. Effectively, we increase the protection as the product gets higher up the range. In our latest Super Nova we actually have 100,000 amps of protection on every single outlet socket. It's an ironically named product because it can't go supernova, it's an unbreakable kind of thing.”

The subjective effects of power cleaning products are, of course, variable. In the same way that you can't really prove the new Land Rover's off-road capability just by driving it up a kerb, those living in areas with good mains won't reap the same benefits as those where it's laced with distortion. Yet there's still a demonstrable difference in my part of world – rural Wiltshire – where the mains distortion is usually around 2% (rising or dropping depending on the time of day) according to the display on my IsoTek Mosaic. In central London, mains noise can be much more – and in hi-fi shows, worse still. Most people who attend one of Keith's many demonstrations at these events usually walk out convinced that power cleaning makes a difference.

StereoNET interviews Keith Martin of IsoTek

IsoTek Mosiac EVO3

“In just general terms, you get a lowering of the noise floor”, explains Keith. Subjectively, music becomes more dynamic because the contrast between the loudest and quietest parts is now larger. That's why people talk of “inky black backgrounds”, and suchlike. You'll also hear less of an edge to the music too as if the upper midband and treble no longer sounds chromium plated. The higher up our range you go with power cleaning products, the more you notice this, but there are radical improvements to soundstaging to be had, too. There's a more expansive recorded acoustic, wider from left to right and deeper from front to back. It's quite shocking that just cleaning the power line correctly can have that big effect on a really good audio system.”

StereoNET interviews Keith Martin of IsoTek

Keith and an IsoTek PCB

IsoTek has a wide range of power cleaners and regenerators and takes its entry-level products just as seriously as its expensive kit, says Keith. “Even with our more inexpensive products, we try and clean as big a frequency range as we can. For example, we use double the amount of copper that we need on the PCBs in order to ensure very low resistance, and always make sure that no two outlet sockets are directly connected together. It costs us more time and more internal wiring, but it's about doing the job correctly. As you go up our range you then go into multiple power cleaning systems within a single chassis – six power cleaners in one box effectively, if we have six output sockets or twelve in the case of the Nova. It's much more complex than throwing a big toroidal transformer in a box with a simple filter network and adding lots of sockets at the back – it's a completely a different thing.”

StereoNET interviews Keith Martin of IsoTek

IsoTek Corvus - Part of the Discovery range

The range is wide, to put it mildly – and may confuse some newcomers to the brand due to its depth and breadth. He explains that the entry-level Discovery range is effectively mains filters with multiple distribution sockets. “It's a very good filter network, designed for a purpose which is used across six outlets with each single socket referencing back to that PCB individually. If you imagine a snake in a river to be noise, if it fell down a waterfall, it couldn't very easily swim back up. That's kind of what we try to do electrically, within the product. Once mains noise hits a PCB, we make it very hard for it to move across to the next socket.”

StereoNET interviews Keith Martin of IsoTek

IsoTek's mains regeneration products started with the EVO 3 range. “These offer full sine wave generation, where we take alternating current, turn into DC and then using a very low distortion synchronous sine wave oscillation system and a power amplifier, we construct a brand new mains sine wave with as low distortion as we can. This gives the piece of connected equipment the best power it can have. It's like having your own miniature power station for each one of those connected pieces but is only suitable for lower current drawing source components. It comes back with a fraction of the noise that came in from the mains and can have a profound effect on the sound. The music sounds smoother but more alive, with far better handling of microdynamics – you can easily lose yourself in a recording.”

StereoNET interviews Keith Martin of IsoTek

IsoTek Sirius EVO3

Keith reckons his company's basic power cleaning products are some of the best in the world. “They're insanely reliable and pretty much bomb-proof. For ninety percent of people, they're fantastic. But for those wishing to really invest in their overall systems, we offer three models of sine wave generation – which is a far more complex technology. We do this properly; unlike some products on the market that basically internally generate a template of a mains sine wave that the incoming power is compared to, we don't feel that's full regeneration. Full regeneration as in Genesis goes further. Nothing of the original is retained. DC has no harmonic distortion or even 50/60Hz. A master reference just like other process is fed to a large power amplifier and a considerable power output is made possible. It isn't added or subtracted. It's total recreation.”

StereoNET interviews Keith Martin of IsoTek

IsoTek's regeneration approach is such that you can put pretty much anything into them,” says Keith, “a square wave or whatever, and it will always be output as a very low distortion mains sine wave. A fascinating trick on our higher-end products is to switch the distortion display to the output THD, and then turn off the connected load, and you'll notice the distortion figure drop. It shows those connected pieces of equipment are creating differential mode noise, and our sine wave generator is actually fighting against it to give it the purest wave that it can. Even so, it's normally around twenty times lower than the input distortion…”


Designed for high current draw applications, IsoTek's new Super Titan is the company's statement product, from the flagship Ultimate range. “I was at the Consumer Electronics Show in Las Vegas a number of years ago and realised that there was a need to create an ultimate series of cost-no-object power cleaning systems for these huge American power amplifiers. I have a BA Hons in Industrial Design, so normally I'm responsible for the external architecture of our products. But for this, I teamed up with another designer, because it was such a complex challenge and we wished to consider resonance issues. Initially, my electrical engineer Nigel Pearson said I was crazy to even suggest designing a 32-amp power cleaning system with ultra-low distortion and massive current reserves, but we started to research it all the same. We ended up having to make our own rack around it.”

StereoNET interviews Keith Martin of IsoTek

IsoTek Super Titan

Keith explains that he teamed up with gifted engineer Kurt Olbert to create a special sub-chassis with an elaborate structure to control vibration and manage heat dissipation. “In uniform structures, sound and noise travel very quickly – and that is not what you want”, he says. “You want to create a chaotic material for dealing with resonances. There was no budget for this product, we just carried on until we achieved our intended result, and the price reflects what it cost. If you go out to push the limits of what can be done, then that is where it is at. We always start from a completely blank zero line taking the knowledge that we know, taking the technologies that we developed and applying the best intellect that we can.”

He says all IsoTek products sport the best components that can be reasonably used. “Quality of parts, quality of design, quality of assembly – are all critical. We don't just measure to assess which parts to use, we listen too – because hi-fi is not just about measurements. You can literally take a polypropylene capacitor and a paper-based capacitor and measure them, and they'll be exactly the same. Put them into an audio circuit, or even a power cleaning circuit, and they will affect the sound in different ways, however. So, it's not just enough to have a good performing 'on paper' product, it also has to preserve the emotion in the music, its dynamics, timing, detail and so on.”

StereoNET interviews Keith Martin of IsoTek

“For example, the internal wiring that we use in products like the Aquarius is solid core Ohno continuous cast copper with silver plating and a virtual air dielectric. It costs about ten times as much as a generic multi-strand copper cable, but we've chosen to make it ourselves to a very high specification because it sounds and performs better. Components are designed and made specifically for the printed circuit boards – you can't go to Radio Spares and buy them. It's kind of like using fresh herbs on an omelette because they taste so much better than dry herbs!”

Keith explains that along with sound quality, the other reason for this attention to detail is durability and longevity. “For example, the stresses on IsoTek sine wave generators are much larger than for normal Class AB power amplifiers. The latter is only really struggling at full output on musical crescendos, whereas our amplifiers are running flat out continuously. So for example, when we were designing the Mosaic, we bought a thermal imaging camera, so we actually see where all the heat was within the product to ensure we positioned critical components in cool areas. We also managed the convection cooling within the product to make sure it was as reliable as possible.”


A generation ago, the average household had far fewer gadgets. Maybe only the refrigerator was kept on all the time because there were no wireless routers or iPhone chargers running permanently. Things are very different now, though, and Keith thinks it makes paying attention to AC mains all the more important. “The number of switch-mode power supplies and general things that ripped up the purity of the mains was much lower back then, but it's now much worse and isn't going to get any better. We are using more and more electrical devices and getting ever more noise coming in.”

StereoNET interviews Keith Martin of IsoTek

With this in mind, IsoTek is pressing on. “We've got some interesting stuff coming out this year. We have a voltage stabilisation system that we've been working on for many years, but it is finally concluded which I'm extremely excited about. For example, if you're in a bad area for mains and are getting voltage drops down to something like 170V, we'll be able to push it back up to 230V. Also, we're now shipping custom installation products in the form of fully programmable smart power systems, which support Crestron and Control4 with dedicated drivers. Wherever you are in the world, you can remotely log on to a security interface and control the IsoTek power product in your home. It's quite a thing!”

Keith believes that mains products are more relevant than ever now, and he's probably right. As we move into a world of ever greater electrification – electric vehicles being the next big thing, of course – mains conditioning and regeneration makes greater sense. “I think people are starting to realise how important clean mains is for a good sounding hi-fi system, it's an integral part. We're continuously thinking about the challenges of the future and fully intend to play our part in it.”

Visit IsoTek for more information


David Price's avatar

David Price

David started his career in 1993 writing for Hi-Fi World and went on to edit the magazine for nearly a decade. He was then made Editor of Hi-Fi Choice and continued to freelance for it and Hi-Fi News until becoming StereoNET’s Editor-in-Chief.

Get the latest.

Sign up to discover the best news and reviews from StereoNET UK in our FREE Newsletter.

Posted in: Hi-Fi Technology Industry
Tags: isotek 


Want to share your opinion or get advice from other enthusiasts? Then head into the Message Forums where thousands of other enthusiasts are communicating on a daily basis.