If we want good quality sound system,the first thing to consider is that a good pre-amp.
Some people say that’s not necessary. But when the low-level audio source.
We may need to adjust the sound too high will cause distortion.
so should have the preamplifier to amplify a signal up before to the our power amplifier.
And I use transistors to build as small pre-amps because.
1. I am familiar with it than other devices. Even though the quality is good.
2. There are many to choose from build circuits.
3. Lower noise. Compared with ICs.
4. Cheap, easy to find accessories.
Seeing these advantages. Let’s consider circuits different example, I would suggest the following.
Circuit Pre-Amp With Transistor
When you want to enlarge sound signal from all source before costume amplify. Usual use Pre Amplifier or Pre Amp. Today I begs for to suggest again the one circuit. That interesting because of use Transistor just one ( the number replaces many the number such as C1815 or C945 or C828 , etc. ) The circuit easily and still be usable well. convenient for a novice as an example PCB be the character Stereo. Wasp Input from the CD player and Output with the amplifier immediately. Request enjoy please yes.
Simple pre-amplifier with transistors BC547
The preamplifier circuit is a circuit that extends the signal from the source sound to signal the strength to go into a power amplifier circuit to trigger the required sector preamplifier is also due to signal from the source voice Some levels. sounds very light, such as tape or tuner, some will have strength of signals in the heart uV is required to use the preamplifier circuit expanded signal strength to strength in the area mV to access the power amplifier for amplifier efficiency.
By entering into power supply 9volt circuit Q1 and Q2 to a direct coupling circuit to transmit better. When the signal input through the C1 coupling into the signal to Q1.
Amplifier to a level of C to stand out in Q2 into the amplifier once again to provide better stability. Then signal to leave the output pin C of Q2 through C6 coupling signal from output and the output signal a part of Q2 will feed black feedback through to the C4, C3 and R3 comes to the pin E in Q1 in order to help the range of frequency response.
With superior audio output that can be connected to the amplifier region.
Pre amplifier with transistors BC548
Pre amplifier circuit with transistors can be used to supply source from 6-12Volt the current minimum is 2-3 mA and can extend the signal strength from up to 2 Volt, which can
This will signal the driver to easily power amplifier and frequency response can be frequency response from 70 Hz – 45 kHz at -3 dB and distortion less than 0.1%.
By entering into power supply circuit and one audio Input. The signal is coupling through C1 to prevent DC Voltage to Harry and then audio goes into the leg B of Q1 to amplify signals to forces up to the one with the R1 and R2 is the organized bias for Q1 is Q1. and Q2 is connected to a direct coupling circuit broadcast better. Then the signal was expanded to export the C leg of Q2 and through C5 coupling signal to smooth out and send it to Su output gain of the circuit, which can be set from the R6/R5 C3 acts as a wizard. high frequency response better.
R9 is connected to the circuit when the circuit for use in the nature of the pre mic R9 acts as the power supply to the mic condenser used if the nature of the pre amp is not integrated into the R9.
Cassette Preamplifier by transistor BC109
This is circuit Cassette Preamplifier. I used transistor BC109 main part electronics.
It is very easy pre amplifier for cassette tape or car audio. but old circuit, I like this curcuit because it is classic. detail more please see in image.