Class H03F : AMPLIFIERS
Subclass 1/28: Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements Modifications of amplifiers to reduce influence of noise generated by amplifying elements in discharge-tube amplifiers
| Patent # | Title | Filing Date | Issue Date | Patent Owner |
|---|---|---|---|---|
| 11128262 | Low voltage tube circuits | Aug 27, 18 | Sep 21, 21 | Not available |
| 11121678 | Vacuum tube amplification system capable of reducing residual noise and a grounding method thereof | Jun 04, 20 | Sep 14, 21 | ECHOWELL ELECTRONIC CO., LTD. |
| 10755885 | Vacuum tube rear device | Apr 11, 18 | Aug 25, 20 | ECHOWELL ELECTRONIC CO., LTD. |
| 10135402 | Grounding structure and grounding method of vacuum tube audio amplifier | Aug 31, 17 | Nov 20, 18 | ECHOWELL ELECTRONICS CO., LTD. |
| Publication # | Title | Filing Date | Pub Date | Patent Owner |
|---|---|---|---|---|
| 2017/0085,227 | HIFI AUDIO TUBE AMPLIFIER | Sep 16, 16 | Mar 23, 17 | SENNHEISER ELECTRONIC GMBH & CO. KG |
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