Audio power amplifier (power amplifier)

Performance of the prototype
Output power (RMS ):… 140W into 8 ohms, 200W into 4 ohms
Frequency Response:. 20Hz – 80kHz-1dB points (see Figure 1)
Input sensitivity: ………… 830mV for 200W into 4 ohms
Distortion: … <0.1% (20 Hz – 20 kHz) (see Fig.2) Signal-to-Noise Ratio:. > 102dB unweighted, 105dB A-weighted with respect to 200W into 4 ohms.

Audio power amplifier (power amplifier) ​​is an electronic plane that serves to strengthen the voice signal that can be derived from a radio, tape recorder, cd player, preamp mic or the other. Audio power amplifier OCL system load with power amplifier connected directly (direct copel) without using capacitors and transformers. Application of OP Amp 741 IC is used as a booster ahead of the audio amplifier circuit to replace the transistor as an amplifier front.

The problem of this research is how the performance of audio power amplifier OCL system by applying OP Amp IC 741 as the amplifier front. The purpose of this study was to investigate the characteristics of an audio amplifier OCL system by applying the Op Amp IC 741 as an amplifier ahead and realize the audio amplifier OCL system by applying the Op Amp IC 741 as the amplifier front. The benefits of this research is for researchers to apply the theories that have been obtained while for the reader is to provide reference and add to the treasury the power amplifier circuit audio field.

The results of this study was to realization of an audio power amplifier OCL system by applying OP Amp IC 741 as the amplifier front. In the measurement, audio power amplifier has a strengthening registration 13.33 times or a total of 22.49 dB at a frequency of 5 Hz and 10 Hz. Strengthening increased to 18.89 times, or 25.52 dB at a frequency of 15 Hz. At a frequency of 20 Hz to 20 KHz has strengthened 24.44 times or 27.76 dB. On the frequency of 25 KHz to 35 KHz strengthening fell to 23.89 times, or 27.56 dB. While on a theoretical calculation is 26.45 times the amount of reinforcement. There is a difference in the strengthening of 2.01 times. Magnitude percent error of measurement is 8.22%. Differences between measurements and calculations that occur due to several things, among others: the calculation of unknown obstacles contained in the circuit path, whereas in reality a series of lines on the PCB also has a value of resistance other than that there are constraints on the instruments will also affect the results of measurements . The quality of the components and the quality of measuring instruments used also affects the measurement results obtained. The most important characteristic of the audio amplifier is the frequency response, expressed by a graph of frequency response. Based on research data indicated an audio power amplifier with good characteristics, namely the audio frequency (20 Hz - 20,000 Hz) has a reinforcement of the same or equal.

Suggestions from this study, an audio power amplifier OCL system by applying the Op Amp IC 741 as an amplifier of this front with further research can be used as a reinforcement tool other instrumentation. It is recommended to install the heatsinks are sufficient in 3055 and 2955 TIP transistors for the transistor is not easily damaged, because the heat generated is large enough.