Any one knows exactly who invented the parametric EQ. I think it must have been post tubes equipment.
Any one knows exactly who invented the parametric EQ. I think it must have been post tubes equipment.
Wikipedia sez-
Daniel N. Flickinger introduced the first parametric equalizer in early 1971. His design leveraged the high performance op-amp of his own design, the 535 series (USPTO #3727896) to achieve filtering circuits that were before impossible. Flickinger's patent (USPTO #3752928) from early in 1971 shows the circuit topology (Figure 2.) that would come to dominate audio equalization until the present day, as well as the theoretical underpinnings of the elegant circuit.
Patent US3752928 - Amplifier system utilizing regenerative and degenerative feedback to shape ... - Google Patents
Your neighbors called. They like your music.
Prior art? http://www.massenburg.com/wp-content.../GM_ParaEQ.pdf
OG, you may be interested in the references to Dolby.
A forum discussion: http://www.gearslutz.com/board/so-mu...metric-eq.html
Last edited by mah; September 18th, 2013 at 08:55 PM.
Opinion is only as valid as its verifiable supporting evidence.
Serious error in the Gearslutz forum. Massenburg's device was only quasi-parametric, in that it only offers partial control, frequencies not sweepable, only selectable fixed points. Not a full parametric.
Parametric has FULL control of frequency, width, and cut/boost. Frequencies and width were variable before Massenburg. Just as we can build different frequencies and slopes in passive crossovers, the same could be done in line level passive filters. It took the opamp to make these parameters continuously variable. Massenburg may have had the concept, but not the execution.
Your neighbors called. They like your music.
Wow!! Interresting discussion. It looks like an evolution from fixed to variable band width in the late 60's to early 70's.
More like 1930's till present, and they are still evolving.Originally Posted by LICORNE
Your neighbors called. They like your music.
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