Table of Contents
Preamplifier circuit diagram with op-amp 12v. Audio preamplifier circuit with op amp, can use various dual operational amplifiers such as TL072, NE5532, OPA2134, CA1458, RC4588, LM358, LM4558, NJM4560, LM258. Circuit using few components and easy assembly, includes single and double-sided board.
About the Audio Preamplifier Circuit with Operational Amplifier
The scheme uses an operational amplifier circuit in inverter configuration, using a simple power supply with a 12V to 24 VAC transformer and LM7812 voltage regulator.
It is configured for gain of about 6X, gain that can be adjusted by changing 2 resistors, R2 and R9.
R2=R9:
10K = Gain 4
5.6K = Gain 2.5
22K = Gain 10
To do the calculation, use the calculator or the various tools available for mobile and computer.
The assembly is simple, using few components. The capacitors in the audio part should be of good quality, give preference to use operational amplifier sure to be original.
It has two options of printed circuit board, being a double-sided one that can be ordered from PCB manufacturers, it also has a single-sided version that can be used in the assembly of a homemade preamplifier.
The PCB is 50 mm x 32 mm, when ordering boards you can use the 2 × 3 panel order, so ordering 5 boards will get you 30 boards in the panel.
The purpose of the preamplifier is to raise the level of the audio signal to be delivered to the power amplifier, i.e., the power amp requires a 500mV signal at the input and the signal source is only 100mV. The pre-amplifier will boost this signal to get the most out of its power.
Some operational amplifiers that can be used are TL072, NE5532, OPA2134, CA1458, RC4588, LM358, LM4558, NJM4560, LM258 and others.
The power supply can be a simple source or a transformer, ideal for applications where it is not possible to use a symmetrical supply.
Audio preamplifier circuit diagram with TL072 or equivalent
Suggested PCB for mounting the audio preamplifier with ne5532 or equivalent.
BOM to assemble an audio preamplifier circuit with operational amplifier.
Last update: 02/22/2022 19:10
| Part | Value | Description | Quantity |
| B1 | DB102 or equivalent | Bridge rectifier | 1 |
| Capacitors | |||
| C1, C2 | 100nF | Ceramic Capacitor | 2 |
| C3, C5, C6, C7 | 4.7µF/16V | Electrolytic capacitor | 4 |
| C4 | 2200µG/25V | Electrolytic capacitor | 1 |
| C8 | 470µ/16V | Electrolytic capacitor | 1 |
| C9 | 100µF/16V | Electrolytic capacitor | 1 |
| C10, C11 | 100p | Ceramic Capacitor | 2 |
| Semiconductors | |||
| IC1 | NE5532N or equivalent | Double operational amplifier | 1 |
| IC2 | LM7812 | 12V positive voltage regulator | 1 |
| Resistors 1/4W | |||
| R1, R8 | 2.2K | Red, Red, Red, Gold. | 2 |
| R2, R9 | 15K | Brown, Green, Orange, Gold. | 2 |
| R3, R4 | 10K | Brown, Black, Orange, Gold. | 2 |
| Miscellaneous | |||
| CN1 | Power | 2-Way Connector Terminal Block 3.5 mm. | 1 |
| CN2 | IN | Jst Xh 2-Way Connector, 2.54 mm pitch or equivalent. | 1 |
| CN3 | OUT | Jst Xh 2-Way Connector, 2.54 mm pitch or equivalent. | 1 |
| Solder, Wires, Printed Circuit Board, Housing, 12V transformer | |||
Download files for this assembly, includes PNG, PDF, PS and Gerber plates
- PDF datasheet of the DB101, DB102, DB103, DB104, DB105, DB106, Db107 rectifier bridge
- Datasheet in PDF format of the NE5532 operational amplifier IC
- Datasheet in PDF format of the operational amplifier IC TL072
- Datasheet in PDF format of the operational amplifier IC OPA2134
Where i conect c10, c11? They not exist in circuit for n5532!
Thx
Hello Anghel Cosmin
Download PCB files, in “dupla face” PCB.
Please, can you tell to me where i place the c10 and c11 (100pf)? From your new diagram they not appere any more?
Thx