Portable Musical Instrument Amplifier

FIG. 1 is a schematic drawing of a prior art guitar amplifier system.

FIG. 2 is a schematic drawing of a guitar amplifier system, according to the present invention.

FIG. 3 is a perspective view of the guitar amplifier according to the present invention.

FIG. 4 is a side view of the guitar amplifier according to the present invention.

FIG. 5 is an end view of the guitar amplifier of the present invention taken along line 5--5 of FIG. 4.

FIG. 6 is another end view of the guitar amplifier according to the present invention taken along line 6--6 of FIG. 4.

FIG. 7 is a bottom view of a guitar amplifier system according to the present invention taken along line 7--7 of FIG. 4.

FIG. 8 is a front view of an electric guitar with an output jack on its front face into which the guitar amplifier of the present invention is inserted.

FIG. 9 is a side view of a second embodiment of the guitar amplifier according to the present invention.

FIG. 10 is a top cross-sectional view of the second embodiment of the guitar amplifier according to the present invention taken along line 10--10 of FIG. 9.

FIG. 2 is a schematic drawing of a guitar amplifier system according to the present invention for which no interconnection cable between guitar 102 and amplifier 120 is needed. Instead, input plug 124 of portable amplifier 120 is inserted directly into output jack 104 of guitar 102. Again, output signals from guitar 102 are monitored through headphones 118 which are connected to the end of portable amplifier body 122 opposite input plug 124 by means of plug 114 at the end of headphone cable 116.

FIG. 3 is a perspective view of the guitar amplifier 120 of the present invention. Input plug 124 extends from clip 126 on face 128 of body 122 and is electrically coupled to the electrical amplifying and signal processing system in body 122 (not shown). Any conventional, compact amplifying system can be used, but it is preferred that the system described in my copending application be employed On back surface 130 of body 122 are mounted tone control dial 132 and on/off volume control dial 134. The function and circuitry underlying these controls is fully discussed in my above-referenced, copending application. Within body 122 is a power source 136 (shown in phantom) for amplifier 120. Preferably, this power source is a conventional 9 volt battery. Battery 136 is electrically coupled to amplifier 120 by means of a conventional 9 volt battery connector 138 having leads 140 and 142.

FIG. 4 is a side view of the guitar amplifier system according to the present invention showing door 144 through which battery 136 (not shown in FIG. 4) is accessed. Door 144 is upwardly slided by pushing door opening surface 146 upward in the direction of arrow A toward top surface 156. Also mounted on the same side of amplifier 120 as door 144 is switch 148 by which the degree of the amplifier overdrive can be modified. Switch 148 is movable between a full distortion setting 150, an edge or moderate distortion setting 152, and a clean or no distortion setting 154. The function of and circuitry for these settings is fully discussed in my copending application. FIG. 4 also shows output jack 158 mounted on back surface 130 which is shown in more detail in FIG. 5.

FIG. 5 is an end view of the guitar amplifier of the present invention taken along line 5--5 of FIG. 4. Besides having output jack 158 into which a mating headphone jack can be plugged to monitor output, back surface 130 is also provided with an input jack 160 for providing the amplifier with auxiliary input signals besides those received from the guitar--i.e., signals from a radio, phonograph, or tape player. These auxiliary signals are summed or mixed with the signals from the electric guitar for simultaneous monitoring through headphones 118 or another output device.

FIG. 6 is another end view of the guitar amplifier of the present invention taken along line 6--6 of FIG. 4. As shown in this drawing, center line CL of input plug 124 forms the center for circle C which circumscribes bottom wall 157 and the lower part of side walls 155 of amplifier 120. As discussed in more detail with respect to FIG. 8, it has been discovered that if the diameter of circle C is no more than 0.800 inches (i.e., bottom wall 157 and the lower portion of the side walls 155 of amplifier 120 are within 0.800 inches of center line CL of input plug 124), amplifier 120 can be used in conjunction with most guitars regardless of whether it has a face-mounted (FIG. 8) or side-mounted output jack (FIGS. 1 and 2). The diameter of circle C must be less than or equal to 0.800 inches.

FIG. 7 is a bottom view of the guitar amplifier according to the present invention taken along line 7--7 of FIG. 4 showing input level control 162. The circuitry and function underlying input level control 162 is fully discussed in my above-referenced, copending application.

FIG. 8 is a front view of an electric guitar with an output jack 166 transversely mounted on its face 164. This is distinct from guitar 102 shown in FIG. 2 where output jack 104 is mounted on the side of the guitar. In guitars with output jacks like that shown in FIG. 8, output jack 166 is recessed below the surface of face 164, and output jack slot 168 slopes downwardly toward output jack 166. As a result, it is necessary for amplifier 120, and particularly its body 122, to have a configuration which can be received by guitar output jack slot 168 as input plug 124 is inserted into output jack 166, as shoWn by arrow B. Accordingly, as discussed with respect to FIG. 6, it is necessary that center line CL of input jack 124 can be no more than 0.800 inches from bottom wall 157 and the lower portions of side walls 155. Amplifier 120 is thus capable of use in conjunction with most electric guitars regardless of where its output jack is located.

FIG. 9 is a side view of a second embodiment of the guitar amplifier 220 of the present invention, while FIG. 10 is a top cross-sectional view of the second embodiment of the guitar amplifier of the present invention taken along line 10--10 of FIG. 9. As in the first embodiment, amplifier 220 is provided with a body 222 having top surface 256, bottom surface 257, and back 230 with tone control dial 232 and on/off volume control dial 234. Unlike the first embodiment where input plug 124 was rigidly fixed to face 128, input plug 224 of the second embodiment is movable relative to face 228 (and body 222). This is accomplished by mounting input plug 224 to face 228 by means of adaptor 270 which is pivotally connected to body 222 by means of transversely-mounted pivot pin 272. As a result, input plug 224 can be moved about an angle .theta. of about 90.degree. with respect to body 222, as shown in FIG. 9. Input plug 224 is electrically connected to the electronic amplifying and signal processing system (not shown) within amplifier 220 by leads 240 and 242.

Although the invention has been described in detail for the purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.