Guitar amplifier with channel-dedicated power switching

• US 7,602,927 B2
• Filed: 09/07/2004
• Issued: 10/13/2009
• Est. Priority Date: 09/07/2004
• Status: Active Grant

• Current Assignee: Mesa/Boogie Limited (Gibson Brands, Inc.)
• Original Assignee: Mesa/Boogie Limited (Gibson Brands, Inc.)
• Inventors: Smith, Randall C.
• Primary Examiner(s): Faulk; Devona E
• Application Number:
  US10/936,152
• Publication Number:
  US 20060050900A1
• Time in Patent Office: 1,862 Days
• Field of Search: 381/118, 381/120, 381/123, 381 61- 63, 847/35, 847/36, 330/51, 330/10, 330/124.R, 330/276.1
• US Class Current: 381/120
• CPC Class Codes: G10H 1/0091 Means for obtaining special acoustic effects combined with modulation G10H1/043
• CPC Class Codes: G10H 1/16 by non-linear elements G10H1/14 takes precedence
• CPC Class Codes: G10H 1/18 Selecting circuits
• CPC Class Codes: G10H 2210/311 Distortion, i.e. desired non-linear audio processing to change the tone color, e.g. by adding harmonics or deliberately distorting the amplitude of an audio waveform distortion functions G10H2250/201, G10H2250/205
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal

Abstract

An amplifier for electric guitar including a plurality of foot switch selectable preamplifier channels which can be set to provide differing sonic characteristics, and also including a power amplifier section for driving a loudspeaker that can be switched between at least two different power or performance capabilities. User operable switching dedicated to at least one of the preamplifier channels is provided to select preferred power amplifier parameters in conjunction with differing channel voicings. Thus, differing preferred power amplifier characteristics may be pre-set and assigned to individual preamplifier channels and called up automatically in conjunction with the remote channel selection.

Claims

1. A guitar amplifier comprising:

an output device;

an input terminal;

a power amplifier section coupled to said output device capable of providing a plurality of power levels;

a plurality of preamplifier channels connected in parallel and coupled to said power amplifier section and said input terminal; and

means to selectively activate one of said plurality of preamplifier channels and one of said plurality of power levels while concurrently deactivating the rest of said plurality of preamplifier channels.

2. The guitar amplifier of claim 1 wherein said means to selectively activate is configured to selectively activates one of said plurality of preamplifier channels and one of said plurality of power levels concurrently.

3. The guitar amplifier of claim 1 wherein said means to selectively activate is a manually-operated switch.

4. The guitar amplifier of claim 1 wherein said output device is a transformer winding having a pair of opposing ends.

5. The guitar amplifier of claim 2 wherein said output device is a transformer winding having a pair of opposing ends.

6. The guitar amplifier of claim 1 wherein said plurality of preamplifier channels is two, each of said plurality of preamplifier channels having a different audible characteristic.

7. The guitar amplifier of claim 2 wherein said plurality of preamplifier channels is two, each of said plurality of preamplifier channels having a different audible characteristic.

8. A guitar amplifier comprising:

an input terminal;

an output device;

a push-pull power amplifier circuit having a plurality of stages and coupled to said output device;

a first preamplifier channel and a second preamplifier channel, said first preamplifier channel and said second preamplifier channel each selectively couplable to said input terminal and said push-pull power amplifier circuit; and

switch means configured to selectively electrically decouple one of said plurality of stages from said push-pull power amplifier circuit;

wherein each of said first preamplifier channel and said second preamplifier channel is concurrently selectable with one of said plurality of stages of said push-pull power amplifier circuit.

9. The guitar amplifier of claim 8, wherein said push-pull power amplifier circuit comprises:

a first pair of electron conducting devices, each having an electron emitter, an electron collector, and a control element to control electron flow between said electron emitter and said electron collector, the electron collector of each of said first pair of electron conducting devices coupled to said output device, each electron emitter of each of said first pair of electron conducting devices coupled to a reference source; and

a second pair of electron conducting devices, each having an electron emitter, an electron collector, and a control element to control electron flow between said electron emitter and said electron collector, the electron collector of each of said second pair of electron conducting devices coupled to said output device, each electron emitter of each of said second pair of electron conducting devices configured to be coupled to a reference source;

said switch means configured to selectively decouple said second pair of electron conducting devices from said push-pull power amplifier circuit and selectively couple one of said first preamplifier channel and said second preamplifier channel to said output device and selectively decouple the other of said first preamplifier channel and said second preamplifier channel from said output device.

10. The guitar amplifier of claim 9 wherein said switch means is configured to selectively decouple said second pair of electron conducting devices by decoupling the electron emitter of each of said second pair of electron conducting devices from said reference source.

11. The guitar amplifier of claim 8 wherein said output device includes a transformer winding having a pair of opposing ends.

12. The guitar amplifier of claim 9 wherein said output device includes a transformer winding having a pair of opposing ends.

13. The guitar amplifier of claim 10 wherein each of said first pair of electron conducting devices and said second pair of electron conducting devices are a pair of vacuum tubes, and one vacuum tube from each of said pairs of vacuum tubes is coupled to a different one of said opposing ends of said transformer winding.

14. The guitar amplifier of claim 11 wherein each of said first pair of electron conducting devices and said second pair of electron conducting devices are a pair of vacuum tubes, and one vacuum tube from each of said pairs of vacuum pairs is coupled to a different one of said opposing ends of said transformer winding.

15. The guitar amplifier of claim 9 wherein said switch means includes a first switch configured to selectively decouple said second pair of electron conducting devices from said push-pull power amplifier circuit and selectively couple one of said first preamplifier channel and said second preamplifier channel to said output device and selectively decouple the other of said first preamplifier channel and said second preamplifier channel from said output device.

16. A guitar amplifier comprising:

an output device;

an input terminal;

a power amplifier section coupled to said output device capable of providing a plurality of power levels;

a plurality of preamplifier operational modes capable of providing differing performance characteristics and coupled to said power amplifier section and said input terminal; and

means to selectively activate one of said plurality of preamplifier operational modes and one of said plurality of power levels while concurrently deactivating the rest of said plurality of preamplifier operational modes.

17. The guitar amplifier of claim 16 wherein said means is a manually-operated switch.

18. The guitar amplifier of claim 16 wherein said output device is a transformer winding having a pair of opposing ends.

19. The guitar amplifier of claim 17 wherein said output device is a transformer winding having a pair of opposing ends.