H03F3/28 - CPC Classification Index

ClassID:

219244 ⎘

H03F3/28 - CPC Classification

Classification description:

Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements; Push-pull amplifiers; Phase-splitters therefor with tubes only

Recent Application in this class:

20240072742

2024-02-29

TUBE AMPLIFIER

20220385253

2022-12-01

Valve amplifiers

20190348957

2019-11-14

Audio amplifier circuit

20150280667

2015-10-01

Programmable Vacuum Tube Bias Control

20120313707

2012-12-13

Push-pull amplifier having inductive common mode decoupling

20120152089

2012-06-21

Amplifier with selectable master control

20110311076

2011-12-22

Method for adjusting the maximum output power of a valve power amplifier stage for an audio amplifier, and corresponding valve power amplifier stage

20110199155

2011-08-18

Controlling the Performance of a Thermionic tube

20110170716

2011-07-14

Methods and apparatus for variable solid state-to-tube rectification in an amplifier

#10

20110135116

2011-06-09

Method and apparatus for biasing an amplifier

#11

20110043278

2011-02-24

Method and apparatus for biasing an amplifier

#12

20100033245

2010-02-11

Controlling the performance of a thermionic tube

#13

20060012424

2006-01-19

Methods and apparatus for variable harmonic distortion

#14

15473137

2018-03-13

Incremental wattage reduction in a vacuum tube amplifier