EK040 Audio Mixer 4-ch mono 5 - 15V
Part.no: 41037857
Description
EK040 is a simple audio mixer with four input channels, tone control (tilt equalizer) and individual mute buttons for each channel.
The mixer can be powered with a range of different power sources and works from around 5V up to 15V. Both AC and DC power supplies work as there is a full-wave rectifier onboard. The rectifier makes it possible to use power supplies with both center-positive and center-negative DC plugs. The PCB has mounting holes for a 9V battery holder that can be attached to the back side (holder sold separately).
The level for the incoming audio is adjusted using the four potentiometers and are then mixed together. After mixing, the signals pass through a simple tilt equalizer, which is also controlled using a potentiometer. Low frequencies are boosted and high frequencies attentuated when the pot is turned to the left. When turned to the right, low frequencies are attenuated and high frequencies boosted. The EQ is flat when the pot is centered.
Each channel can be muted using the four push buttons. When a channel is muted, the LED above the button will light up.
The mixed signal output can be adjusted with a master gain pot. The fixed amplification for the mixer can be set by using different values for the resistor R16 (R_GAIN).
Component list
| RefDes | Value | Qty. | Marking |
|---|---|---|---|
| C1, C2, C3, C4, C14 | Film capacitor 1uF | 5 | 1J63 |
| C5 | El.lyt 470uF | 1 | 470uF 16V |
| C6, C7 | El.lyt 10uF | 2 | 10uF 50V |
| C8, C9 | Ceramic capacitor 100nF | 2 | 104 |
| C10, C11 | Ceramic capacitor 100pF | 2 | 101 |
| C12, C13 | Film capacitor 10nF | 2 | 103 |
| D1, D2, D3, D4, D5 | LED 5mm red | 5 | |
| D6, D7, D8, D9 | Diode 1N4148 | 4 | 4148 |
| J1, J2, J3, J4, J5 | 3.5mm female stereo | 5 | |
| J6 | DC jack 2.1/5.5mm | 1 | |
| R1, R2, R3, R4, R17 | Resistor 24kohm | 5(+1) | |
| R5, R6, R7, R8, R14, R15, R18, R21, R22 | Resistor 47kohm | 9(+1) | |
| R9, R10, R11, R12, R13, R19, R20 | Resistor 10kohm | 7(+1) | |
| R16 | Resistor (10k/24k/47k) | * | R_GAIN |
| SW1, SW2, SW3, SW4 | Push button 2-pol on-on | 4 | |
| SW5 | Slide switch 1-pol on-on | 1 | |
| U1 | OP amplifier LMV58 | 1 | LM358AP |
| VR1, VR2, VR3, VR4, VR5, VR6 | Potentiometer 100kohm lin | 6 | B104 |
Assembly guide
Start by checking that all components are included. Check the component list. Do a visual inspection of the PCB and make sure it's free from damage.
Start by mounting all the resistors, the four rectifier diodes and the IC socket. Place and solder all resistors of the same value first, before continuing with the next.
As the 3.5mm jacks, the slide switch and the ceramic capacitors are all of similar height, it's a good idea to mount these components next. Place the jacks and hold them in place when the board is turned. Use the panel PCB as a clamp to hold all the sockets in place at the same time.
The DC jack is mounted the same way as the other jacks. It's a good idea to solder just one pin first, adjust the position if necessary, before soldering the rest of the pins.
Continue with the film and electrolytic capacitors. Be observant of the polarity of the electrolytic capacitors. Compare the markings on the board with the components.
Mounting the LEDs and push buttons require some finesse as the LEDs should be mounted with some spacing and the buttons must be properly centered to fit the holes on the panel PCB. Start by placing the LEDs in the correct places. Attach the caps to the push buttons and place them on the board.
Attach the hex spacers to the panel PCB and mount it to the component PCB.
Push the LEDs down as far as they go towards the panel and solder them in place. Make sure the push buttons are centered before soldering them. Please note that both LEDs and buttons need to be oriented the correct way to work. Be observant of the markings on the PCB.
When all the components are mounted, but before installing the OP amplifier, a final voltage check using a multimeter can be useful. Measure the pins of the IC socket; Pin4: 0V, Pin3,Pin5: 1/2x supply voltage, Pin8: supply voltage.
Finish the assembly by attaching the bottom panel and front panel PCBs using the included screws, spacers and washers.
Interactive assembly guide ↗
Simulation ↗
Schematic
Dimensiones
