Ted Fletcher

TFPRO/Alice Ltd. Airsound Technology LLP.



Ted Fletcher, December 2014


1954 Age 13 built a working machine recording audio onto magnetic paper tape (with father John E Fletcher).
1964 developed a system for controlling the speed of model trains using ‘constant current’ technique from first principles.
1966 developed a hybrid valve/transistor audio amplifier used at KPM Studios, Denmark Street, London.
1967 developed optical based audio compressor used at KPM studios.
1974 invented the ‘superbal’ balanced audio input circuit for achieving minimum noise on audio lines.
1975 invented the transconductance power amplifier and used it in Independent Local Radio station talkback systems.
1978 invented an audio limiter for use in the Alice 828 mixer.
1980 developed a solid state ‘hybrid transformer’ for use in telephone ‘phone-in’ programmes.
1981 further developed the ‘hybrid’ making it automatic balancing.
1984 developed the hybrid for use in ‘in-car’ telephones.
1985 invented a transformerless system to achieve correct balanced mixing in large audio consoles.
1986 applied transconductance amplifiers to large studio loudspeakers for the first time.
1988 invented an audio harmonic enhancer used in the JoeMeek VC1 voice channel.
1989 invented the classic ‘Joe Meek’ audio compressor with circuitry and techniques to mimic the dynamic response of the human ear.
1998 invented and patented ‘airSound’ as a technique for producing spatial sound from a single source.
2000 invented current mode distortion free transformer input circuitry.
2002 invented a 3-speaker version of ‘airSound’ as used in the Orbitsound ‘Spaced360’.
2015 developed the Orbitsound ‘D1’ loudspeaker (With Daniel Fletcher).
2016 invented an electronic circuit to apply transconductance to a pulse-width modulation (pwm) power amplifier for audio use.
2021 Invented and developed a feed forward analogue compressor (TFPRO 588).