If friends are looking Dynamic Microphone Preamplifier circuit is high quality, a low noise signal. I suggest these circuits. Because They use the transistors as main. Which typical transistor amplifier with low noise this circuit, too. There is about 200-300 times the gain. The frequency response is 50Hz to 100KHz.
These circuits use the 12 volts to 24 volts DC power supply.
And, they are designed for low impedance microphones or about 200 Ohms.
I like to collect a lot of circuits. Many circuits I have built before. But people have said they are good for them. Like these circuits, I still build them. But they may are useful for you.
See below: 4 circuits with PCB layout for easy to build
2 Transistor Dynamic Microphone Preamplifier
This is a simple microphone preamplifier circuit that uses 2 transistors are connected with direct coupling, to respond to the signal even better.
How it works
In Figure 1 the circuit diagram
On the collector of Q2 will feedback signal to the emitter of Q1. To frequency response is improved.
And, at the same time, R1 will connect voltage from the emitter of Q2 to bias Q1.
The input signal into C1 to the amplifier by Q1, Q2. Then, there is the output signal at the collector of Q2 through capacitor-C6 to a power amplifier.
For the power supply of the circuit. We may use simple circuits as shown in block dash include Full wave rectifier D1, D2, and capacitor filter C7.
But someone who wants a high-quality power supply should use a 12V DC regulator.
The Shopping list
Q1-Q2: BC548, BC547, BC549_45V 100mA NPN Transistor
0.25W Resistors, tolerance: 5%
R2: 680 ohms
R4, R5: 220K
C1: 1uF 50V
C2,C4: 4.7uF 16V
C7: 1,000uF 25V
C3: 100pF 50V Ceramic capacitor
How to builds
This circuit is easy and uses a few parts. So, you can build it on the universal PCB. However, some want to make it on the normal PCB. See an actual-size of the Single-sided Copper PCB layout below.
And see the components layout of this project.
Dynamic Microphone Preamplifier using 3 transistor
You can see the project Dynamic Microphone Preamplifier using C945 transistor 2 vertion and easy to build with pcb layout see below.
Here is a Circuit diagram of Pre MIC – 3 Transistors on Mono
- Q1-Q3: 2SC945, 2C1815, 2SC828, 45V 100mA NPN Transistor
0.25W Resistors, tolerance
How to build
This circuit is easy. You may make it on the universal PCB or Perforated PC board. However, some want to make a PCB see in the image below.
The Actual-size of Single-sided Copper PCB layout
Then see components layout here
Are you clear view? See the components and wiring layout on PCB. below
Not only that
2nd circuit: 3 Transistor Dynamic Microphone Preamplifier
- Simple condenser Mic Preamplifier circuit
- 9 Tone control Stereo Preamplifier circuit with PCB
- Flyback transformer tester circuit using 2SC828
Pre MIC mono using 2 Transistor C945
This is low noise microphone preamplifier circuit, by 2 Transistor mono part name C945 or C828 or 2SC829 or C458.
The supply volt is 12V – 24V. Easy to build and low cost.
I have an old microphone,I want to make play with common amplifier. It does not sound much. Must to use pre amp before.I search a lot of circuits, see this circuits it very well for me,low cost, use transistor.
Circuit of Pre MIC mono by 2 Transistor C945
PCB of Pre MIC mono by 2 Transistor C945
- 4 types of Preamplifier circuits
- 3 Low noise Microphone Preamplifier using ICs
- Simple dynamic and electret condenser microphone preamp circuit
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