SPECIAL EFFECT AMPLIFIER FOR ELECTRICAL MUSICAL INSTRUMENTS

• US 3,812,278 A
• Filed: 02/01/1972
• Issued: 05/21/1974
• Est. Priority Date: 02/01/1972
• Status: Expired due to Term

• Current Assignee: Gretsch Company The
• Original Assignee: John L. Aker
• Inventors: Aker, John L.
• Primary Examiner(s): Wilkinson, Richard B.
• Assistant Examiner(s): Weldon, U.
• Application Number:
  US05/222,524
• Time in Patent Office: 840 Days
• Field of Search: 84/1.16,1.24,1.25 331/59,108,135,167
• US Class Current: 84/705
• CPC Class Codes: G10H 1/02 Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos

Abstract

A special feature or effect portion of an amplifier for musical instruments has circuitry combinations for generating vibrato, tremolo, fuzz and wah-wah or selective boost. The subject amplifier includes circuitry which permits independent selection of vibrato or tremolo and a combination of the two on an independent basis. Additional circuitry uniquely affects the oscillator therein, switching, vibrato and tremolo modulation, boost or wah-wah production and the fuzz producing means.

Claims

1. In an amplifier for electrical musical instruments having means operably connecting an input, a preamplifier, a special effects circuit, a power supply and an output, the improvement comprising said special effects circuit and having a means for producing vibrato in said output, means for producing tremolo in said output, means interconnecting said vibrato producing means with said tremolo producing means, means interconnecting said vibrato producing means with said input, means interconnecting said tremolo production means with said output, means interconnected with said tremolo producing means and said vibrato producing means for modifying the effects produced by both of said means, said modifying means including means for separating the phase of said vibrato and said tremolo signal effects by substantially 180*, and an electric controlling means interconnected with said vibrato producing means and between said tremolo producing means and said modifying means, the controlling means operable to independently control a linear passage of said input signal through said vibrato producing means and said tremolo producing means.

2. A combination as in claim 1 wherein said tremolo producing means includes an amplifier means, a tremolo switch, and an interconnecting means connecting said switch and said amplifier means for modulating the gain of said amplifier in a controlled fashion, said interconnecting means in said amplifier cooperating to maintain said amplifier output without a net decrease in said amplifier signal when said controlling means is selectively operated to switch on said tremolo producing means for a tremolo effect.

3. The combination as in claim 1 including an oscillator, said oscillator having an output interconnected with said vibrato producing means, and means fOr shifting the phase of said input passing through said vibrato producing means at a rate controlled by said oscillator output.

4. The combination as in claim 1 wherein said tremolo and vibrato modifying means includes an oscillator having a phase inverter therein, said inverter interconnected with said vibrato producing means and said tremolo producing means to maintain said substantially 180 degree phase separation between said vibrato and tremolo signal effects.

5. The combination as in claim 1 wherein said special effect circuit includes an oscillator, said oscillator having an output interconnected with said vibrato producing means and said tremolo producing means, said oscillator having only one variable element for controlling the center frequency of said oscillator output.

6. The combination as in claim 5 wherein said variable element is resistive in nature and manually variable.

7. The combination as in claim 5 wherein said oscillator includes an amplifier, a band pass filter, and means for interconnecting said amplifier and said filter to provide positive feedback at the center frequency of the band pass filter.

8. The combination as in claim 5 wherein said oscillator circuit includes an inverter having an output therefrom, means for substantially symmetrically clipping the inverter output, means for feeding the clipped output to the input of said filter, said filter operable to pass only the fundamental component of said clipped output thereby producing a low distortion signal at more than a fixed frequency.