Sound production apparatus
US6111968A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1997 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Jul 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/181
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A sound production apparatus has a speaker, an amplifier circuit that includes at least one electron tube, and a portable housing that encloses the speaker and contains the amplifier circuit such that the speaker is fully enclosed within the housing. In a particular implementation the amplifier circuit includes an input connector, a first triode connected to the input connector, a gain adjustment variable resistance connected to the first triode, and a second triode, which second triode is connected to the gain adjustment variable resistance. A tone adjustment section has a treble tone adjustment variable resistance, a bass tone adjustment variable resistance, and a midrange adjustment variable resistance, all connected to the second triode. A volume adjustment variable resistance is connected to the tone adjustment section, a pentode is connected to the volume adjustment variable resistance, and a transformer is connected to the pentode. A chassis on which the amplifier circuit is mounted forms part of a back wall enclosing the speaker, and the triodes and pentode are mounted to the chassis such that they are on the outside of the back wall but the remainder of the amplifier circu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.