text: In the same decades, similar electro-acoustic instruments — i.e. electric-fan driven free reed organs with additional electronic circuits — were developed also in Japan. Magna Organ invented in 1934 by a Yamaha engineer, Sei-ichi Yamashita, was a multi-timbral keyboard instrument similar to the Hoschke's instrument developed in the same year, although it utilized the microphones in the soundproof box instead of the electrostatic pickups. Initially the Magna Organ was designed as a kind of the additive-synthesizer that summing-up the partials generated by the frequency-multipliers. However, it seems difficult to achieve polyphony without intermodulation distortions with the technology of the 1930s. According to the additional patents and the reviews at that time, its later implemented design, seems to had shifted to a sound-colorization system using the (various) combinations of reed sets, microphones and loudspeakers.
  This type of instrument was later re-commercialized: In 1959, Japanese organ builder, Ichirō Kuroda, built his first Croda Organ with each pair of constantly oscillating free reed and a microphone in the soundproof box, and installed at Nishi-Chiba Church in Chiba Prefecture.
  (1930s–)
  On the other hand, the Hammond Novachord (1939) and other competitors selected the subtractive synthesis design using various combinations of oscillators, filters, and possibly frequency dividers, to reduce the huge number of oscillators, which was the bottleneck of the additive synthesis design. The heat generated by early models with vacuum tube tone generators and amplifiers led to the somewhat derogatory nickname "toaster". Today's solid-state instruments do not suffer from the problem, nor do they require the several minutes that vacuum tube organs need to bring the filament heaters up to temperature.