Presence control for guitar amplifier
US7412064B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Mar 20, 2003 |
| Grant date | Aug 12, 2008 |
| Priority date | — |
| Expiry date | Mar 2, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/541
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A guitar amplifier having at least one channel, each channel having a differential amplifier with first and second amplifying members, each amplifying member having a control element, an electron emitting element and an electron collecting element, the electron emitting elements of the amplifying members commonly coupled and an output amplifier coupled to the differential amplifier and having an output terminal selectively coupled to the control element of the second amplifying member of the differential amplifier as a feedback path. An input terminal coupled to the control element of the first amplifying member and a user-adjustable presence control circuit selectively coupled between the control element of the first amplifying member and ground to increase the perceived brightness, when selected. The presence control circuit includes a high pass filter disposed between the input terminal and ground to filter a selected high frequency portion of the signal received at the input terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.