Audio playback systems
US4220817A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1978 |
| Grant date | Sep 2, 1980 |
| Priority date | — |
| Expiry date | Sep 15, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G5/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Improved circuitry for providing bass control in audio playback systems using feedback circuits wherein undesirable deviations in frequency response above the bass region exhibited by previously available Baxandall feedback circuits are substantially eliminated by utilizing, in a preferred embodiment, a voltage follower amplifier, such as an emitter-follower transistor circuit in association with a single capacitance in the bass control circuit, which eliminates the undesirable frequency response deviations at the mid-frequency and higher frequency ranges so that frequency response curves at all settings of the bass control substantially coincide above the bass region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.