Graham Slee Lautus RCA Interconnects

Graham Slee Lautus RCA interconnects are designed to deliver the very best connection with thanks to strategically placed Ferrites to reduce the effects of RF interference and deliver a much clearer and open sound with more instrumental layering - much more three-dimensional and with better extension at both ends of the audio spectrum.

What's the Problem?

For years audio interconnect manufacturers have put ferrite sleeves on their cables because it looked 'cool'. Some even decorate them, and some fit fancy cases around them. The problem is that if you don't know what you're doing how can you sell the idea? Graham Slee say they know what they're doing and here's the explanation. The audio signal 'runs along' cables but it doesn't run through a preamplifier. A preamplifier makes facsimiles of the signal with the aid of its power supply - the number of facsimiles of facsimiles depends on the number of stages the preamp has. 

Audio Signals Explained

The output of a preamplifier is, therefore, a signal-modulated power supply voltage. CD players, phono preamps and D to A converters all have preamplifier stages which produce the output signal in the same way. No matter how much care has gone into the design of a preamp and its power supply - or your 'mains cleaner' if you have one - it's quite possible for strong radio carrier waves to appear on the signal-modulated power supply voltage we call the output signal.

More than that, preamps are just small amplifiers - they don't drive speakers, but they are otherwise essentially the same. They can be near to perfect but some high-frequency output oscillation is possible, especially on complex and loud passages of music.Also, the outputs of D to A converters (DACs) and CD players can still contain high-frequency clock artefacts. Add all those together and that's what passes along the audio interconnect to the next stage - often a power amp or integrated amp, a headphone amp or even an A to D converter for 'ripping' high-quality transfers.

Better Sound Quality

Placing one or two ferrite sleeves at arbitrary places on an audio interconnect cable will lead to random results. Few of us have the cash to play roulette with interconnects. Therefore there has to be a method of determining where they're placed for best effect. Listening is too subjective a method, so science has to pin down the correct positions, then listening will reveal if the science got it right.

Luckily all the science was done many years ago by radio engineers but not for the reasons we're doing it. When using cables for radio, they are transmission lines and require accurate tuning for the length to obtain maximum power for aerial transfer. You'll remember that Graham Slee used to work in professional broadcasting?

Radio waves being much shorter than audio signal wavelengths, means that at the frequencies we want to reduce, a complete wavelength will 'fit' within a cable length of between one and three or four metres. We want to find where the wavelength is at its peak amplitude and if you ever saw a sine wave on an oscilloscope you'll note that it swings up and down by the same amount about its axis. The first peak is its quarter wavelength, its half wavelength is where it crosses its axis, and where it peaks in the opposite direction is its three quarters wavelength position.

We need to apply attenuation at one of the peaks. Attenuation, where it crosses its axis, is pointless because there is no amplitude to attenuate there. The best place to apply attenuation is at its first peak along the cable length - its quarter wavelength.

But at what frequency? This is where assumptions have to be made and listening tests confirm or reject the assumption. My starting point was to assume the most popular transmission bands are the most powerful ones and these are the 100MHz radio broadcast band (FM) and the 200MHz digital radio broadcast band (DAB).

Why Use Ferrites?

Placing suitable ferrites at the points where these frequencies quarter wavelengths are, resulted in a much clearer and open sound with more instrumental layering - much more three-dimensional and with better extension at both ends of the audio spectrum. This confirmed to me and my listening panel that the science correlated with the audible results.

Can any piece of cable and ferrite sleeve do the same? No. The cable velocity factor or dielectric constant has to be known. The ferrite sleeve has to have the right frequency range and attenuation rate which is dependent on its electrical properties. These are our trade secret and I can't discuss them with you.

I have however given you the 'bones' of how these interconnect work. They work equally as well in digital and video applications as well as USB Audio. The following tabs will reveal all our current applications of the 'Lautus' technology, and by browsing through them you'll find a suitable interconnect for your needs.

(Note: the Lautus interconnect cables should not be seen as a solution for RF problems in badly designed amplifiers although in some cases they can affect a cure)