The Revolution of the Magnetic Sound Expander: “Shaping Magnetic Fields Variably Opens Up Completely New Possibilities”
With his Magnetic Sound Expander (MSE), Stefan Jordan of Jordan Guitars proves that electric guitar innovation is still alive and kicking. The German guitar builder had his idea patented and strives for it to become a more mainstream feature on electric guitars and other instruments.
Imagine being able to preserve all the frequencies of the overtone spectrum so that your guitar always sounds natural and alive. The Magnetic Sound Expander has actually made this a reality.
In this interview, Stefan, who hails from Enneptal in Germany, explains how his invention came about, how it works and why you’d want one.
Let’s dive in!
What specific problem with existing guitar tone controls inspired you to develop the Magnetic Sound Expander (MSE)?
The usual passive tone control can only reduce and cut. Here, electronic components are used to post-process the signal that has already been created – with an unavoidable loss of quality.
I wanted pickups with variable characteristics that make it possible to change the frequency response while playing – from creamy to mainstream to harder sounds.
The magnetic fields that transmit the string vibrations to the pickups are influenced without electronic components.
Can you explain in simple terms how the magnetic field manipulation affects the frequency response of the guitar?
When the MSE is activated, all frequencies are attenuated, but to different degrees: the higher the frequency, the more it is reduced, but never completely canceled out. The frequency response shifts its peak to the left, and the output is reduced slightly, i.e. the sound becomes softer and slightly quieter.
All frequencies of the overtone spectrum are retained so that the guitar always sounds natural and lively, even when fully attenuated by the MSE. The intensity of the MSE’s effect is infinitely variable.
Why did you concentrate on second-order low-pass filtering and not on other approaches to sound shaping?
Initially, I wanted to shape sound by influencing magnetic fields without using electronics. There were several approaches to this; what remained as the main claim after the examination and granting of the patent was the second-order low-pass filter.
Tests have shown that this is the most practicable solution (Thanks to the DPMA, the German Patent and Trademark Office, for the first opposition – that turned the idea into an invention).
What were the biggest technical challenges in developing a purely magnetic solution without electronics?
The practical implementation. Mechanics need to be designed, space for attaching additional parts is tight, it should make as little noise as possible, be easy to reach but not get in the way when playing and, of course, look good, too.
How does the interaction of the MSE with different pickup types (single coil, humbucker) differ?
In principle not at all. The effect of the MSE always works the same, but the intensity can be predisposed by varying the material thickness of certain parts.
How strongly the MSE affects the respective pickup also has to do with the magnets used. With Alnico 2, the effect is strongest, and you don’t need much, while Alnico 5 or strontium ferrite (ceramic magnets) require correspondingly thicker MSE parts.
How do you manage to preserve the natural sound of a guitar and at the same time use the filter functions of the MSE?
The MSE is not a filter! There is no frequency that the MSE cancels out completely. All overtones are retained, only the emphasis changes.
How did your experience from the magnetism projects of the Wuppertal company influence the development of the MSE?
Years of studying the behavior of alternating magnetic fields and wondering about their effects on electric guitars gave me the idea for the MSE.
When it came to practical implementation, I benefited from a lot of experience in troubleshooting and working with different materials and tools. That’s why I’m very grateful for over 16 years at Karl Deutsch.
What role did your background as an electrical machine assembler and guitarist play in the design of the MSE?
My profession (from the age of 17) provides the knowledge about magnetic fields. My passion for guitars (from the age of 10) and my curiosity about physical processes (from the age of 0) also played their part.
Can you explain the typical installation process of the MSE on a guitar?
One option is to attach additional parts to an existing guitar, e.g. the control unit can be screwed together with the tailpiece and guide units with the pickup frames.
The other option is to build a guitar with the technology integrated into the body.
What prompted you to apply for patent protection in Germany, South Korea, the USA and Europe?
When I first came up with the idea, I had a clear idea of the change in sound and dynamics that it would make possible when making music.
As the MSE intervenes in the signal chain at a point that had previously remained untouched, I thought the idea was worthy of a patent – being able to shape magnetic fields variably opens up completely new possibilities.
The selection of countries was based on strategic considerations in conjunction with financial possibilities. I hope that there will be many licensees for the patent and that the MSE will become widespread.
Can you describe a specific moment during the development when you knew you had something special?
Originally, I just wanted to build an electric guitar for myself and first of all, I informed myself, googled, and thought about it… After reading a rather polemic text about electric guitars on the Internet, written by an electrical engineer, I was in my yard (cigarette break), thinking about a single sentence in this article.
It was about magnetic flux and its influence on the guitar signal. Then I had the idea of making this influencing factor variable – and an MSE movie played in front of my inner eye and ear, which I simply had to turn into reality.
How does the MSE fit into the current trend towards analog or digital sound shaping in guitars, in your opinion?
Just as well as in traditional sound shaping. MSE can be used with all old and new amplifier designs and also with all effect devices.
A guitar with quickly interchangeable pickups also works with all conceivable setups. MSE offers pickups with variable frequency response; the setup is up to you.
What test procedure do you use to ensure consistent performance of the different MSE units?
The performance is constant by design. You can pre-set the performance by trying out different thicknesses of the copper sheets used in the MSE to adapt the performance of the MSE to the pickup used.
How do professional guitarists react to the MSE compared to traditional tone controls?
The only professional guitarist who has tested MSE so far took advantage of the additional option and was enthusiastic. It is definitely useful in the studio, he said, but it is impossible to say in general terms how useful it is when playing in a live context because the conditions are very different.
The feedback at the Guitar Summit 2024 in Mannheim was almost exclusively positive and there were a lot of visitors. I can’t say whether there were any professional guitarists there.
There were no prominent musicians at our stand. Instead, there were guitar teachers, dealers, luthiers, pickup manufacturers and lots of amateur guitarists.
What is your vision for the expansion of MSE technology beyond its current application?
A remote control with pedal is planned so that you no longer need a hand to operate it. Both a cable pull mechanism and a radio or infrared remote control are feasible.
Has the transition from working with magnetism in the industry to the guitar world presented any particular challenges?
Yes, the biggest challenge is working alone. There are two sides to that. On the one hand, you are free to make your own decisions, but on the other hand, there is no one to help you.
On top of that, I have to deal with commercial and legal issues that are new to me.
How has the guitar community in Ennepetal and NRW supported your innovation?
I haven’t approached people in the region yet. The plan is to go more public at the beginning of 2025.
What advantages does the MSE offer for sound engineers and producers?
To be honest: none directly. At most, working with guitarists who are in a better mood…
Are you developing variants of the MSE for different types of electrical instruments?
I haven’t started construction yet, but planning is underway. The next step will be string instruments. I have already contacted Sarah C. Meyer, a violin maker from Wuppertal, about this.
The design work will start at the beginning of 2025. As soon as prototypes are ready, this will be communicated on jordan-guitar.com and luthiera.de. The aim is to develop a new type of electric violin – viola – cello and a mounting kit for acoustic string instruments.
The MSE principle works with all magnetic pickups for stringed instruments.
What advice would you give to other innovators in the field of guitar hardware based on your patent experience?
Be open to new things, collect ideas everywhere, evaluate everything, even the crazy ones! And then experiment wherever you can!
What about your lutherie? How’s that going?
Unfortunately, I am not able to offer guitars at this time. I am seeking business partners – specifically, guitar manufacturers who can produce the three models I have developed and designed, as well as licensees interested in offering guitars with MSE and upgrade kits.
I want to avoid inquiries that I cannot fulfill, as I have focused solely on development and prototyping until now.
