Musical instrument pickup systems and sustainer systems

• US 5,200,569 A
• Filed: 06/14/1990
• Issued: 04/06/1993
• Est. Priority Date: 05/27/1988
• Status: Expired due to Term

• Current Assignee: Fernandes Co., Ltd., Lerner David Littenberg Krumholz & Mentlik LLP, Rick Knotts, Steve Moore
• Original Assignee: Steven M. Moore
• Inventors: Moore, Steven M.
• Primary Examiner(s): Witkowski, Stanley J.
• Application Number:
  US07/538,240
• Time in Patent Office: 1,027 Days
• Field of Search: 84/723-742, 84/DIG. 10
• US Class Current: 84/723
• CPC Class Codes: G10H 3/18 using a string, e.g. electric guitar mechanical features G10D1/085
• CPC Class Codes: G10H 3/26 using electric feedback
• CPC Class Codes: Y10S 84/10 Feedback

Abstract

A pickup system for providing sounds for a musical instrument has a feedback circuit for converting a pickup signal representing a vibration of a string or other vibratory element to a drive signal. The pickup system includes a pickup coil, an electromagnetic source which generates a magnetic flux, a device such as a ferromagnetic element for magnetically linking the electromagnetic source and the pick up coil with the vibratory element, a step-up transformer having a primary coil section and secondary coil section, a connection between the pickup coil and the primary coil section of the step-up transformer, an output terminal and circuit elements for connecting the output terminal to the secondary coil section of the step-up transformer. Preferably, the pickup system includes a sustainer having a sustain feedback circuit for accepting a feedback signal which represents the motion of the vibratory element wherein the sustain feedback circuit includes an operational amplifier, a first and a second network and a switch for selectively directing the feedback signal through one of the networks to one of two input terminals of the operational amplifier. In another preferred embodiment, a sustainer for a musical instrument includes a switchable sustain circuit having an inverting and non-inverting signal path which have different frequency response characteristics.

Claims

1. A sustainer for a musical instrument having at least one vibratory element comprising:

(a) drive means for accepting a signal and applying a driving force to a vibratory element of the instrument responsive to said drive signal;

(b) a sustain feedback circuit for accepting a feedback signal representing motion of said vibratory element and conducting said feedback signal to said drive means, whereby said drive means will apply said drive force to said vibratory element responsive to said feedback signal, said sustain feedback circuit including a mode select means for selectively altering said feedback signal, said mode select means including;

(1) An operational amplifier having inverting and noninverting input terminals, an output terminal, and an amplifier feedback circuit connected between said output terminal and one of said input terminals of said operational amplifier;

(2) A first network having a first network input terminal and a first network output terminal connected to one input terminal of said operational amplifier;

(3) A second network having a second network input terminal, and a second network output terminal connected to the other input terminal of said operational amplifier, said first and second networks having different frequency transfer functions, each of said networks having reference means for connecting its network output terminal to a reference potential; and

(4) Switch means for selectively directing said feedback signal to said operational amplifier through one of said networks and disconnecting the other one of said networks.

2. A sustainer as claimed in claim 1 wherein said reference means of each said network includes a reference resistor connected between the network output terminal of that network and a source of said reference potential.

3. A sustainer as claimed in claim 2 wherein said first network includes a first branch having a capacitor and a resistor connected in series between said first network input terminal and said first network output terminal and a second branch in parallel with said first branch, said second branch having a resistor

4. A sustainer as claimed in claim 3 wherein said second network includes a capacitor connected between said second network input terminal and said second network output terminal.

5. A sustainer for a musical instrument having at least one vibratory element comprising:

(a) drive means for accepting a signal and applying a driving force to a vibratory element of the instrument responsive to said drive signal; and

(b) a sustain feedback circuit for accepting a feedback signal representing motion of said vibratory element and conducting said feedback signal to said drive means, whereby said drive means will apply said drive force to said vibratory element responsive to said feedback signal, said sustain feedback circuit including an inverting signal path and a noninverting signal path, said noninverting signal path and said inverting signal path having different frequency response characteristics, and mode switch means for selectively directing said feedback signal through either one of said signal paths to said drive means while disabling the other one of said signal paths.

6. A sustainer as claimed in claim 5 wherein said noninverting signal path is operative to pass signal components at all frequencies within the range of fundamental frequencies of the instrument, said inverting signal path being operative to substantially block signal components below a preselected cutoff frequency..

7. A sustainer as claimed in claim 5 wherein said inverting and noninverting signal paths have different phase shift characteristics.

8. A sustainer as claimed in claim 7 wherein each said signal path is operative to impart a phase lead to said feedback signal, the phase lead imparted by said noninverting signal path increasing with frequency, the phase lead imparted by said inverting signal path being substantially constant for all frequencies passed by said inverting signal path.

9. A sustainer as claimed in claim 8, further comprising phase shifting circuit means for providing a phase lead which increases with frequency, said inverting and noninverting signal paths each including said phase shifting circuit means, said inverting signal path including means for providing phase lead which decreases with increasing frequency.