Q1. Why did you choose wood for cartridge cases?
Firstly, there is one point to be clarified in advance that I am not making cartridge cases with „some“ pieces of wood but only with the varieties of tone wood which are intended for instrument making.
Anyway, at the very beginning, it was quite naive of me to choose wood simply because I was willing to make something important. Then again, it was quite natural for me because at that time, for me the most important thing was my guitar. I naturally had special interests, even a little bit prior knowledge in luthiers work; moreover, since I had no intention to offer my cartridge at large, wood must have been an ideal material being as it was carvable and beautiful.
Thankfully, I could become more and more convinced with my choice over time. Since I only needed very small pieces of wood, I could do my work without being severely affected by their very nature. Instead, the pieces of wood that I was using, offered satisfying lightness and steadiness providing me with various options to form them. Needless to say, there are many materials that are lighter and harder than wood but I haven’t yet found anything which is superior enough to induce me to dispense with the unique beauty of wood.
Last but not least, the materials that I chose, wood, bone, brass, all those have one thing in common. The more time goes by, the more elegant they become.
Q1. What is the specification of TEDESKA mono cartridges?
All types of TEDESKA mono cartridge models are equipped with a vertical shaft generator constructed on the air core coil principle. "Air core coil" describes an inductor that does not use a core which is made of a ferromagnetic material. This covers the cases where there is actually air inside of the windings as well as where the coils are wound on a nonmagnetic insulator – We are now adopting the latter method.
An air-cored inductor is often characterised by great efficiency and dynamism and relatively little distortion. Using this type of inductor is more beneficial when you want to use a high magnetic field strength because its inductance will never saturate. In addition to that, regarding cartridge making, it cannot be overlooked that you can save the weight of the core material which very often results in various favorable characteristics of sound. These are some advantages of air core coil technique from which we benefit.
Q2. What is the specification of TEDESKA Stereo cartridges?
The "Classic" line
The "Progressive" line
The "Solid Core" line
Q1. Development of the generator pole
When the stylus tip is running through the groove of the vinyl, the cantilever and the coils oscillate in a magnetic field and electric signals are created. Under perfect circumstances, the oscillations of the coils during music reproduction perfectly correspond to the record groove. This requires that stylus, cantilever and coils are the only parts of the pickup cartridge that may oscillate. However, this is only a theory as in reality a transmission of oscillations to the surrounding parts cannot be avoided. Speaking of the cartridge only, these parts are most importantly the rear pole plate and generator pole (blue in next figure) which carries the cantilever and the coils together with the damping rubber (shown in red).
The target during the development of the generator is to achieve a design that avoids any interaction between the cantilever parts and the pole components. In terms of vibration, an interaction takes place when two mechanically connected systems incorporate similar frequencies. To prevent any interactions by separating the resonant frequencies of both components from each other as far as possible, we design the pole components to show resonant frequencies far above the frequency range of our cartridges which is 20 Hz to 35 kHz.
To optimize the pole parts to high resonant frequencies we have incorporated numerical simulation techniques in early design stages. With these kinds of simulations it is possible to determine their resonant frequencies in a virtual manner which enables to investigate geometry modifications in detail. The result of this process is a compact design with high stiffnesses of all parts. In addition we found out that adding a stabilizer to the pole part increases the resonant frequency significantly.
The next animations shows the animations of the pole parts eigenmodes with and without stabilizer. Without the stabilizer, the resonance frequency was at 22 kHz and due to the use of the stabilizer it was possible to increase the frequency to 37 kHz. This is a demonstration that the resonances of the pole parts now occur outside the given frequency of our cartridges.
TEDESKA 2018 with the friendly support of Mr. David Funke
TEDESKA BERLIN GERMANY