DE102010018060B4 - Mixing console for audio signals - Google Patents

Abstract

Mixing console for sound signals coming in on at least two channels, which has at least the following circuits: a circuit for previewing the sound signals via a connectable headphone, a circuit for changing the tone color using a sound filter and a circuit for cross-fading and / or mixing sound signals of the channels using a Crossfaders and which has several outputs, characterized in that the audio signals coming in via the channels (2, 3) are headphone output signals from playback devices, the respective channels (2, 3) are divided in terms of circuitry and an amplification-free parallel forwarding to outputs (4, 5) a) via at least one passive sound filter (10) and subsequently a passive crossfader (11) to an output (4) to which an amplifier can be connected, and b) via a switch (6, 7) of the respective channel (2 , 3) to a headphone output (5) of the mixer (1), with the scarf ter (6, 7) the channels (2, 3) can be selected.

Description

The invention relates to a mixer for sound signals, in particular a mixer for a disc jockey (DJ) with the functions pre-listening the sources, change tone color and crossfading / mixing two sources to an output.

Normally, in DJ mixers so-called low-frequency analogue signals (colloquially line or chinch signal) or turntable signals with standardized voltage values are processed.

These signals have to be amplified electronically in order to be processed in a DJ mixer, since signal processing involves signal losses (voltage losses). For an electronic amplification a power supply is always necessary.

Alternatively, the signal processing can also be done digitally, but this type of signal processing also requires a power supply ( GB 2431285 A ).

In order to be able to change the tone color of a sound signal in a DJ mixer, passive sound filters are usually used. However, signal processing by passive sound filters is accompanied by signal losses (voltage losses). To compensate for the losses, the signal must be amplified before or after the filter with power supply.

To blend comfortably from a signal source to a second source, DJ mixers use a crossfader. The circuit connects a signal source to ground through a slide potentiometer (the crossfader) so that the other one can be heard at the output.

In the middle position both signal sources can be heard. The analog circuit of the crossfader is usually accompanied by two downstream resistors with a voltage division, in this case with a halving of the voltage, which in turn must be balanced with an amplifier with power supply ( WO 01/11809 A1 ).

The preview function in a DJ mixer is usually accomplished with active electronic circuits. The input signal is divided and separately amplified for the headphone jack of the mixer.

The disadvantages of such conventional DJ mixing consoles are the necessary own power supply, the weight and the higher dimension, which limits the mobility and flexibility and is ultimately also associated with higher costs.

The object of the invention is to propose a passive DJ mixer that at least the functions: change tone, crossfading / mixing of two sources and Vorhören includes.

This object is achieved with the features of claim 1. Claim 10 describes a further embodiment. Advantageous embodiments are the subject of the dependent claims.

• a) über mindestens einen passiven Klangfilter und nachfolgend einen passiven Crossfader zu einem Ausgang, an den ein Verstärker anschließbar ist, und
• b) über einen Schalter des jeweiligen Kanals zu einem Kopfhörerausgang des Mischpultes, wobei mittels der Schalter die Kanäle auswählbar sind.

According to the invention in a mixer for incoming at least two channels sound signals, which has at least the following circuits: a circuit for pre-listening the sound signals via a connectable headphones, a circuit for changing the tone by means of sound filters and a circuit for blending and / or mixing of sound signals of the channels by means of a crossfader, and which has multiple outputs, suggested that
the audio signals coming in through the channels are headphone output signals from players,
the channels are each circuitarily divided and a gain-free parallel forwarding to outputs is provided

• a) via at least one passive sound filter and subsequently a passive crossfader to an output, to which an amplifier can be connected, and
• b) via a switch of the respective channel to a headphone output of the mixer, wherein by means of the switches, the channels are selectable.

The passive DJ mixer is designed to handle only headphone signals that can be higher in voltage than the commonly used standard signals.

The voltage losses associated with signal processing by passive sound filters are also compensated by the somewhat stronger headphone signals, so that at the output of the passive DJ mixer sufficient voltage is available for the operation of amplifiers for public address systems.

The mixer has at least two channels, each channel having several inputs that can be selectively switched to the respective channel.

First, the existing headphone signal of the two or more signal sources is looped through a mechanical switch to the headphone output of the mixer. The switches are used to select between the channels. In this case, the switches of the channels are coupled to one another such that the headphone output can be operated by one respective switch, while the other switch is connected to an equivalent resistor. Even before the switches, the incoming sound signal is divided and forwarded in parallel via the signal processing (sound filter and crossfader) to the output for the amplifier of the public address system.

The input signal of the passive DJ mixing console is thus directly - and not as usually indirectly via amplifiers - connectable to two consumers:
a headphone to preview with a resistance of about 30 to 100 ohms or a spare resistor and an amplifier of a public address system with an input resistance of about 10 to 20 kOhm.

The replacement resistor is preferably designed as a controllable rotary potentiometer in order to adjust different headphones with different resistances can.

As described above, the analog circuit of the crossfader is usually associated with a voltage division.

In the case of the passive DJ mixing console proposed here, therefore, a new circuit is provided which makes it possible to allow crossfading or mixing without halving the voltage. The signal therefore does not need to be amplified.

Each crossfader has two cooperating adjustment knobs connected in parallel, which have connections for one input signal on both sides and the tap of one adjustment controller is connected to ground, while the tap of the other adjustment regulator is intended for the output signal and both adjustment regulators are controlled in antiphase.

A preferred embodiment provides that the adjustment are mechanically identical slide potentiometer, which are arranged in parallel and electrically connected crosswise and the slide are mechanically coupled to each other and rectified movable.

Such an embodiment of the crossfader is not limited to the mixer described here, but also in other mixing consoles, which work with other input signals, usable, which is why the crossfader is again the subject of a secondary claim.

• – die auf Tonträgern vorhandene Musik durch passive Klangfilter in der Klangfarbe zu verändern,
• – zwei Tonsignale (von einem Abspielgerät zum anderen) lückenlos überblenden zu können bzw. zwei Signalquellen zu einer Summe zu mischen und
• – die Musik der angeschlossenen Geräte vor dem Vorgang des Mischens oder Überblendens einzeln über einen anschließbaren Kopfhörer zu hören bzw. zu kontrollieren.

It is possible with the proposed passive DJ mixer

• - to change the existing music on phonograms by passive sound filters in the timbre,
• - To be able to crossfade two sound signals (from one player to another) seamlessly or to mix two signal sources into a sum and
• - Listen to the music of the connected devices before the process of mixing or crossfading individually via a connectable headphones or control.

The mixer is usually used in consumer or entertainment electronics or in the gastronomy dance or event area.

The implementation is based on analog technology. The device consists exclusively of passive electronic components.

By a small portable construction the device is extremely mobile and flexible in its application. For the user, it requires two players with headphone output, as they are found, for example, the Mp3 players, CD players or mobile phones with integrated Mp3 players, an amplifier with speakers, as they are also found in many areas of life, for example. at the PC workstation, in the living room, in the catering trade, on the stage etc. and the corresponding connection cables.

The mixer according to the invention will be explained with reference to the drawings. In the following, apart from other existing mixer functions, only the three functions relevant to this mixer will be described. Furthermore, it is of course a stereo mixer. In the drawings and explanations, however, only one side of the stereo signal has been shown for ease of illustration.

Show it:

1 Signal flow in the passive DJ mixer,

2 Switch headphone signal / spare resistor,

3 Crossfader,

4 Characteristic of the setting controller and

5 the state of the art of a mixer.

The 1 shows the signal flow in the passive mixer 1 , For comparison was with 5 created an analog image for a conventional mixer.

The over the channels 2 . 3 incoming audio signals are headphone output signals from playback devices.

• a) mindestens einen passiven Klangfilter 10 und nachfolgend einen passiven Crossfader 11 zu dem Ausgang 4 zum Verstärker einer Beschallungsanlage und
• b) über einen Schalter 6, 7 des jeweiligen Kanals 2, 3 zu einem Kopfhörerausgang 5 des Mischpultes 1, wobei mittels der Schalter 6, 7 die Kanäle 2, 3 ausgewählt werden.

The incoming signal of the respective channel 2 . 3 is divided by circuitry and forwarded in parallel without amplification to the outputs 4 . 5 , where the forwarding takes place via

• a) at least one passive sound filter 10 and subsequently a passive crossfader 11 to the exit 4 to the amplifier of a sound system and
• b) via a switch 6 . 7 of the respective channel 2 . 3 to a headphone output 5 of the mixer 1 , wherein by means of the switch 6 . 7 the channels 2 . 3 to be selected.

2 shows a switch combination for a headphone signal at the output 5 , The switches 6 . 7 of the channels 2 . 3 are coupled together, such that through the switch 6 the headphone output 5 from one of the channels 2 . 3 is operable while the other switch 7 the other channel 3 . 2 on a spare resistor 9 on.

Playback devices with a headphone output, such as portable MP3 players, include a small amplifier designed to operate a commercially available headphone with a resistance of about 30 to 100 ohms. The signal voltage (so-called rated voltage) applied to the headphones is usually in the range of approx. 0.3 to 3 volts, depending on the volume.

Without the headphones connected, the headphone amplifier of the player usually provides a slightly higher voltage (the so-called "no-load voltage") than with the headphones connected. In other words, this means that the output voltage can slightly reduce or collapse when loaded by the headphone resistor. How much reduces the voltage of the signal under load, depending on the resistance of the headphone and technical implementation or quality of the headphone amplifier vary greatly or automatically regulated.

Would now the switch 6 from a switching situation in which the on channel 2 incoming headphone signal via the sound filter (s) 10 and crossfader 11 connected to the amplifier of the sound system and at the same time on channel 2 incoming signal at the headphone output 5 heard on the channel 3 Switched, the load would be about 30 to 100 ohms of the headphones 8th omitted with the result that instead of nominal voltage now idle voltage at the output of the amplifier for the public address system is pending - the signal would therefore be undesirably louder at the public address system.

To the signal at the output 4 Therefore, in a preferred embodiment of the passive DJ mixer to keep constant for the amplifier of the public address system 1 when switching from one channel to the other 2 . 3 each a spare resistor 9 the headphones 8th simulate. This ensures that the output voltage for the sound system is cut at a constant level. The switches 6 and 7 are therefore mechanically interconnected as shown.

The replacement resistance should be 9 the resistance of the headphones 8th be approximate, preferably the equivalent resistance 9 adjustable, z. B. a controllable rotary potentiometer.

Furthermore, it is provided that the equivalent resistance 9 a short circuit preventing resistor is connected upstream.

3 shows a preferred embodiment of the crossfader 11 , The crossfader 11 has two cooperating adjustment knobs in parallel 12 . 13 on, which have two-sided connections for an input signal.

The tap of the setting regulator 12 is connected to ground while the tap of the other setting controller 13 is determined for the output signal. Both adjustment controls 12 . 13 are controlled in phase opposition.

The adjustment controls shown here 12 and 13 are sliding potentiometers, which are arranged in parallel and electrically connected crosswise and the slide are mechanically coupled to each other and rectified movable.

If the knob is the far left, signal A is at the output 4 adjacent and signal B grounded, so not at the output 4 fitting. If the control is on the far right, signal B is at the output 4 adjacent and A grounded, so not at the exit 4 fitting.

In the two end positions - far left or right - there is no voltage division between input A or B and output 4 available. The input signal corresponds in voltage level to 100% of the output signal.

In the entire area between the two end positions, a voltage division is present and the signals from the inputs A and B are at the same time at the output 4 fitting.

In spite of voltage division the highest possible output signal, but a not too fast signal increase in relation to the distance traveled by the crossfader 11 to get at the passive DJ mixer 1 the resistance value of the setting controller 12 , whose tap is connected to ground, many times greater than the resistance of the setting 13 with pick-off for the output signal, preferably 7-20 times, and moreover, the resistance of the adjustment knob 12 and 13 a non-linear course.

The following boundary conditions must be considered:
The greater the resistance value of the setting controller 12 in relation to the resistance value of the setting controller 13 the lower the loss at the output. That is desirable.

For adjustment controls 12 In addition, the greater the resistance value of the setting controller, the shorter the path until the other signal voltage becomes larger, since the grounded side then very quickly becomes high-impedance with respect to ground. That is undesirable.

It would be optimal, starting from one end position, a continuous increase of the other signal in relation to the path traveled back, after 50% way both input signals should be 100% at the output. Since the situation of a voltage division exists outside the two end positions, the optimum is not possible.

Thus, starting from an end position, to the middle position of the crossfader 11 a slower increase of the other signal, it is possible, the resistance values of the adjustment 12 and 13 in the beginning and in the end a flat course and in the middle area have a steep course. This is in 4 shown.

LIST OF REFERENCE NUMBERS

1

mixer

2

Channel for the headphone signal of the 1st player

3

Channel for the headphone signal of the 2nd player

4

Output to the amplifier of a public address system

5

Exit to the headphones

6

Switch in the channel 2

7

Switch in the channel 3

8th

headphone

9

Replacement resistance headphones

10

sound filter

11

crossfader

12

Adjustment knob in the crossfader

13

Adjustment knob in the crossfader

A

Input signals crossfader

B

Input signals crossfader

Claims (11)

Mixing console for audio signals incoming on at least two channels, which has at least the following circuits: a circuit for previewing the sound signals via a connectable headphone, a circuit for changing the tone by means of a sound filter and a circuit for fading and / or mixing of sound signals of the channels by means of a Crossfaders and having multiple outputs, characterized in that via the channels ( 2 . 3 ) are headphone output signals from playback devices, the respective channels ( 2 . 3 ) are divided by circuitry and a gain-free parallel forwarding to outputs ( 4 . 5 ) a) via at least one passive sound filter ( 10 ) and subsequently a passive crossfader ( 11 ) to an output ( 4 ), to which an amplifier can be connected, and b) via a switch ( 6 . 7 ) of the respective channel ( 2 . 3 ) to a headphone output ( 5 ) of the mixer ( 1 ), whereby by means of the switch ( 6 . 7 ) the channels ( 2 . 3 ) are selectable. Mixing console according to claim 1, characterized in that the switches ( 6 . 7 ) of the channels ( 2 . 3 ) are coupled to each other, such that in each case by a switch (( 6 ) or ( 7 )) the headphone output ( 5 ), while the other switch (( 7 ) or ( 6 )) to a substitute resistance ( 9 ) is switched. Mixing console according to claim 2, characterized in that the equivalent resistance ( 9 ) the resistance of the headphones ( 8th ) is approximated. Mixing console according to claim 2 or 3, characterized in that the equivalent resistance ( 9 ) is adjustable, preferably a controllable rotary potentiometer. Mixing console according to one of claims 2 to 4, characterized in that the equivalent resistance ( 9 ) is preceded by a short-circuit preventing resistor. Mixing console according to one of claims 1 to 5, characterized in that each passive crossfader ( 11 ) two cooperating adjustment knobs ( 12 . 13 ), which have connections on both sides for an input signal and the tap of a setting controller ( 12 ) is connected to ground, while the tap of the other setting controller ( 13 ) is intended for the output signal and both adjustment controls ( 12 . 13 ) are controlled in phase opposition. Mixing console according to claim 6, characterized in that the adjustment controls ( 12 . 13 ) Are slide potentiometers, which are arranged in parallel and electrically connected crosswise and the sliders are mechanically coupled to each other and rectified movable. Mixing console according to claim 7, characterized in that the ratio of input voltage to output voltage based on the distance traveled by the sliding potentiometer ( 12 . 13 ) has a non-linear, preferably in the end regions a flat course and in the central region a preferably steep course. Mixing console according to one of claims 6 to 8, characterized in that the resistance value of the setting controller ( 12 ), whose tap is connected to ground, is many times greater than that of the setting controller ( 13 ) with tap for the output signal, preferably 7-20 times. Mixer with at least one crossfader, characterized in that the crossfader ( 11 ) two cooperating adjustment knobs ( 12 . 13 ), which have connections on both sides for an input signal and the tap of a setting controller ( 12 ) is connected to ground while the other adjustment knob ( 13 ) is intended for the output signal and both adjustment controls ( 12 . 13 ) are controlled in phase opposition. Mixing console according to claim 10, characterized in that the adjustment controls ( 12 . 13 ) Are slide potentiometers, which are arranged in parallel and electrically connected crosswise and the sliders are mechanically coupled to each other and rectified movable.

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