Wide dynamic range voltage controlled filter for electronic musical instruments
US3974461A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 14, 1974 |
| Grant date | Aug 10, 1976 |
| Priority date | — |
| Expiry date | Jun 14, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S84/09
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A voltage controlled filter for an electronic synthesizer incorporates a plurality of individual voltage controlled filter stages connected in cascade with a variable feedback interconnecting the input and output stages. Each of the stages is controlled by application of a series of pulses, with the period between successive pulses determining the cutoff frequency of the filter. Application of pulses to the filter stages at different pulse repetition rates changes the cutoff frequency of the filter and modifies the relative amplitudes of different frequency components of an audio signal to be passed by the filter. The filter is suited for use with high level signals and provides an extremely wide dynamic range through a very high signal-to-noise ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.