The older model from the portfolio of cartridges of the Swiss company Goldenberg called Maestro received a sapphire needle holder. The Swiss decided not to use boron, which is widespread in such cases, referring to their experience in the field of materials science in application to sound reproduction.
Also worth mentioning is the neodymium magnet system used in the Maestro with a moving coil core made of commercially pure ARMCO iron. The coil itself is wound with 4N grade copper.
The inner case of the cartridge is made of massive bronze coated with an exotic material – ruthenium. Aluminum in gilding was used outside.
The Micro-Ridge diamond stylus removes unevenness in the track, providing a frequency range of 20-30,000 Hz with ± 2 dB unevenness. In this case, the cartridge generates a signal with a peak-to-peak value of 0.4 mV with a maximum level of nonlinear distortion of 0.2%.
The cost of the Maestro cartridge has not yet been announced by Goldenberg Audio.