GB2176077A - Portable multifunctional mixer - Google Patents

Abstract

A portable battery-operated audio signal mixer is embodied as a hand-graspable box 1 carrying a microphone 2, channel controls at 3 and 4, and a slide volume control 5, located under the thumb of a user and plug/socket assemblies, for signal input and output, eg 8, 9, so located as to avoid dislodgement in use. A clip is valuable to locate the device e.g. on a pocket edge when hands are otherwise in use for example with a guitar or other musical instrument. <IMAGE>

Description

SPECIFICATION Portable multifunctional mixer This invention relates to a portable unit for control of playback and mixing of two or more audio channels, and has a primary utility for composing or performing musicians or for teachers of music, although it can also be used for "voice-over" dubbing of a prerecorded or live input, for example by radio commentators, bird watchers or the like.

It is known to record, e.g. onto tape, a signal or performance and thereafter to combine this with a separate musical or spoken channel.

In its simplest form this can be done with two tape recorders. One voice or instrumental line can be recorded on one tape and audibly played back into the microphone of the other recorder while a second voice or line is played into the same or a different microphone. If desired, a number of such voices and lines can be built up. More conveniently the inputs are handled as electrical signals rather than picked up by microphone, the operator using monitor earphones and a "mixer" installation to switch the various inputs on or off or to alter their volume or other characteristics.

Such installations are typically large, fixed installations of some complexity. I have now discovered that there is an advantage in producing a portable device with the basic mixing and dubbing facilities and I have invented a particularly convenient design of such a device which can be readily used by a musician even during his own practice performances.

The invention in one aspect provides a portable self-contained battery operated hand-graspable device for mixing audio signals, comprising a rigid containing box of a size to be graspable by hand with the thumb lying along a side face and with a major front face towards the holer: wherein input and output sockets for wire-carried signals and/or a microphone for pick-up of an audio input, are all located towards one end of the said box to avoid dislodgement of connecting wires and/or covering of the microphone in use.

Preferably an on/off switch for each of at least some input channels of signals is located towards the said one end of the side face for switch movement across the thumb direction. Preferably, moreover, a slide control is located to lie under the thumb of the user for movement in the thumb direction, for example so as to modify the volume.

In preferred embodiment two sockets are formed in the end face of the box and two sockets at or towards the upper end of the other side face (that is to say, the side face remote from the thumb of the user).

The two sockets may be small-calibre sockets, such as are used for e.g. home taperecorders "walkabout" headphones, or like monitor equipment. Larger sockets are more usually used for input leads from musical instruments, or for a larger size tape-recorder input, or for professional-size headphones. By having both the type of sockets a considerably wider range of possibilities of use is thus provided.

Usually, two smaller sockets will be adjacent each other and the larger sockets also adjacent each other.

In another aspect therefore the invention provides a portable self-contained battery operated device for mixing electrical signals comprising a rigid containing box of a size to be graspable by hand with the thumb lying along the side face and a major front face, comprising a microphone, towards the holder: in which a pair of small-calibre sockets and pair of large calibre sockets are provided to allow connection of input signals from a tape or instrument and output signals to both a monitor and recorder, for mixing with the microphone signals, the different calibre sockets allowing alternate modes of connection depending upon the equipment used.

To simplify the controls it is further proposed to dispense with a separate on-off switch for the internal self-contained battery and to modify a socket whereby fixing of a plug therein also connects the circuitry for use i.e. so that the socket itself is an on/orr switch.

The invention will be further described with reference to the accompanying drawings, in which: Figures la and 1b show general external perspective view of the device from the front and from the back respectively, indicating a typical relative layout of control members, input and output sockets, and microphone.

Figure 2a shows by way of example a detail of a battery-holding compartment within the device.

Figure 2b shows a detail of an alternative battery holding compartment, and Figure 3 shows a jack-plug and socket as modified to perform an on/off function as well as a connection.

Figure 4 shows an alternative plug and socket with on-off switch capability, and Figure 5 is a circuit diagram of the device as shown in Figure 1.

The device is externally formed as a box 1 with rounded edges and corners. Typically this box is made of polymer material or cast alloy and should be a robust and heavy grade of polymer e.g. 1/4 inch (6 millimetres) thick or similarly in cast metal, to avoid undesired pick-up of vibrations. A preferred size is about 4 x 2 x 1 inches i.e. 10 x 5 x 2.5 centimetres.

A microphone 2 is provided in the major face at the central line and towards the upper edge. On one side are located two switches 3, 4 for input channels, capable of "horizontal" movement with reference to the drawing orientation (it being understood that in use the device will lie in whatever hand held position may be necessary) and a volume control 5 capable of "vertical" sliding.

On the top face are located two sockets 6, 7 for jack plugs 8, 9 respectively. On the other side are located two large diameter sockets 10, 11 for plugs 12, 13. On the back is a clip 14 and at the bottom of the said other side face, beneath sockets 10, 11 is the openable flap 15 of a battery compartment 16 shown in dotted lines in Figures 1a and 1b.

The exact types of jack plugs and sockets, of slide control, or the provision of a microphone, are all optional. However, attention is drawn to the relative locations of the various plugs and switches and of the microphone in the example shown. If the device as shown in Figure 1 is gripped in the left hand the switches 3, 4 and the control 5 all fall easily for use with the thumb. Moreover, the microphone 2 is not covered by the fingers, which fit beneath the plugs 12, 13: and the plugs 8, 9 are at the top and similarly away from the risk of displacement or discomfort to the user when the device is used in the heat of performance.

For use socket 11 can be connected electrically to a guitar, or large (output) tape recorder, using a iarge-size socket. Socket 12 can be connected to a similar (recording) tape recorder. There is also provided a monitor head connected to socket 7 The microphone channel and the guitar channel can be both switched in or both switched out, of one of the other switched in by suitable manipulation of switches 3, 4. Moreover, the volume of the channels can be altered by slide control 5. When not being held, the device can be clipped at 14 to a pocket edge.

An a#lternative or additional channel could if necessary be added for joint control with the guitar channel, at socket 6. Also, depending on the available equipment, the monitor could run off 10, and the tape off 7, making the equipment multifunctional.

Thus, the equipment performs the function of a mixer deck as used in studios and for editing, but does so with portable equipment simple enough for use by the performers themselves and designed to facilitate such portable use. The device is "on" i.e. the microphone and circuitry are "live" while the socket 10 or 7 is in use, even if the recording channel is disconnected by switches 3, 4.

The device, is as described above, battery operated. As a subsidiary feature I have observed that replacement of batteries in similar equipment can be tiresome and can eventually lead to neglect or lack of full use of the goods. To avoid this I have developed a battery compartment in which the battery can be held in a manner facilitating removal and replacement.

Figure 2a shows a molded polymer box 17 for receiving in a snug fit a battery 18 with top terminals 19, 20 for connection against flexible contacts 21 themselves conventionally linked with the circuitry of the device.

Attention is directed to the stepped rear wall 17a of the box 17. For removal, the battery is tilted back over this step to present a protruding corner which can be grasped by finger and thumb. For replacement the reverse procedure is carried out.

Figure 2b uses the same numerals and shows a similar battery held in a differently shaped box with, however, the same sort of step 17a for the same purpose as before.

An additional feature of value in the embodiment shown above is based the small-scale nature of the device.#ln practice, it is difficult to provide an on/off circuit switch (not to be confused with channel switches 3, 4) in a conventional place-on the device, yet clearly the circuitry cannot be "live" at all times or else daily battery replacement would be needed. I have overcome this problem by the ex pedient shown in Figure 3. Normally, a jack plug. of this type brings its two annular conductors 22, 23 one into contact with each of two connectors 24, 25 to connect the (already live) circuit to, for exam ple, headphones. The jack plugs as shown not only connect into but also complete and hence activate the circuit within the box because the external metal collar 26 is split, and only bridged to earth at 27 when the plug is fully home-in the socket. A modified assembly of different condition is already known for large-calibre sockets. This novel small scale socket is used for the monitor for preference but could be used on the-other socket.

Figure 4 shows an alternative connection mem ber 30 split into two parts 30a and 30b, simulated from each other; and capable of interconnection by, and onward electrical connection at the mem ber 31, to reform the same function as the device shown in Figure 3.

Figure 5 is a circuit diagram for the equipment shown in Figure 1.

Claims (8)

1. A portable self-contained battery operated hand-graspable device for mixing audio signals, comprising a rigid containing box of a size to be graspable by hand with the thumb lying along a side face and with a major front face towards the holder: wherein input and output sockets for wire carried signals and/or a microphone for pick-up of an audio input, are all located towards one end of 'the said box to avoid dislodgement of connecting wires and/or covering of the microphone in use.

2. A portable audio signal mixer as claimed in claim 1 in which an on/off switch for each of at least some input channels of signals is located to wards the said one end of the side face for switch movement across the thumb direction.

3. A portable audio signal mixer as claimed in claim 1 or 2, in which a slide control is located to lie under the thumb of the user for movement in the thumb direction.

4. A portable audio signal mixer as claimed in any one preceding claim in which two sockets are formed in the end face of the box and two sockets at or towards the upper end of the other side face.

5. A portable audio signal mixer as claimed in claim 4 in which two smaller sockets are adjacent each other and two larger sockets are adjacent each other.

6. A portable-self-contained battery operated device for mixing electrical signals comprising a rigid containing box of a size to be graspable by hand with the thumb lying along the side face and a major front face, comprising a microphone, to wards the holder: in which a pair of small-calibre sockets and pair of large calibre sockets are pro vided to allow connection of input signals from a tape or instrument and output signals to both a monitor and recorder, for mixing with the micro phone signals, the different calibre sockets allowing alternate modes of connection depending upon the equipment used.

7. A portable audio signal mixer as claimed in any one preceding claim in which one connection socket is configured as an on-off switch.

8. A portable audio signal mixer as claimed in claim 7 and substantially as herein described with reference to the drawings.