EK019 Preamplifier Stereo
Part.no: 41016510
EK019 is a dual-channel amplifier with adjustable gain. It can be used to amplify very low-level signals to a level suitable for power amplifiers.
Both inputs are AC-coupled and have a frequency range from approximately 5Hz to 25kHz. The gain can be adjusted individually for the left and right channels using the potentiometers on the board.
Each channel is implemented as an inverting operational amplifier that amplifies the input signal from approximately 1x to 100x. If a non-inverting configuration or higher gain is required, the channels can instead be connected in series (INL -> OUTL -> INR -> OUTR).
EK019 is suitable for use with, for example, dynamic microphones, electric guitars, and other signals in the mV range.
- Supply voltage: 5 - 30VDC
- Current draw: 15mA max. (vid 12V)
- Frequency range: 5Hz - 25kHz
- Dimensions: 46 x 32mm
- Mounting holes: c-c 40 x 26mm, ø2.54mm
Component list
| RefDes | Value | Qty. | Part.no. | Marking |
|---|---|---|---|---|
| C1, C4 | El.lyt capacitor 47uF | 2 | 40520024 | 47uF |
| C3, C5, C8, C9 | El.lyt capacitor 10uF | 4 | 40520003 | 10uF |
| C7 | Ceramic capacitor 100nF | 1 | 41003038 | 104 |
| D1 | LED 3mm red | 1 | 40307000 | |
| IN, OUT, VIN | Pin header 2.54mm | 8 | 41001167 | |
| R1, R4, R9, R11 | Resistor 1Mohm | 4 | 40811610 | |
| R2, R3, R5 | Resistor 1.8kohm | 3 | 40811318 | |
| R6, R7 | Resistor 10kohm | 2 | 40811410 | |
| R8, R10 | Trim pot 3266Y 200kohm | 2 | 40900500 | Y 204 |
| U1 | OP amplifier RC4558 | 1 | 40811522 | RC4558P |
Assembly guide
Before starting assembly, verify that the printed circuit board is free from damage and scratches. Check that all components to be installed are present and compare with the component list.
It is recommended to start assembly with the lowest-profile components and proceed to larger components. Begin by placing the resistors in their designated positions. Orientation is not relevant.
Bend the leads to a sharp 90° angle so they fit into the holes on the board. When the resistor is positioned flush against the board, bend the leads outward to prevent it from falling out.
Solder the resistors in place and trim the component leads.
The IC socket has very short leads and it will not be possible to bend them outward to hold it in place before soldering.
Instead, try to turn the board over without the socket falling out and let the board rest on the socket when placed flat on the work surface.
Start by soldering one of the pins. Verify that the socket is still correctly positioned. If it is misaligned, it can still be adjusted by pressing it into position while reheating the solder joint.
The remaining pins can then be soldered in quick succession.
Note that one side of the socket has a marking that must be oriented in the same direction as the component marking on the printed circuit board.
Once the IC socket and resistors are in place, continue with the LED, the ceramic capacitor, and the trimmer potentiometers.
Note that the LED must be correctly oriented to function. The long lead should be inserted into the hole corresponding to the rounded marking on the board, and the short lead into the square hole.
Similar to the IC socket, the trimmer potentiometers can be more difficult than other components to position flush against the board. Use the same method as for the IC socket: solder one lead first, verify and adjust alignment, then solder the remaining leads.
The final components to be installed are the large electrolytic capacitors. Install and solder them in the same manner as the resistors.
Note that the electrolytic capacitors must also be correctly oriented. The long lead should be inserted into the hole marked with "+".
The supplied pin headers can be installed if standard lab wires with DuPont connectors are to be used, but it is also possible to solder wires directly to the board.
Once all components are in place and connectors or wires have been soldered, the operational amplifier can be inserted into the IC socket. Ensure that all pins align correctly with the socket and are not bent. Also verify correct orientation by comparing the board marking with the IC.
Interactive assembly guide ↗
Simulation ↗
Schematic
Drawing
