LA4460 Audio Amplifier 5W

This general-purpose low-power (5 W) audio amplifier is suitable for driving a speaker of approximately 8 to 12 inches. A Sanyo LA4460 IC is used as the audio output IC. The circuit consists of a loudness control, driver amplifier Ql, and bass and treble controls of about ±10 dB boost/cut. It should be useful in a wide variety of situations. Either the ac supply shown can be used, or a 12 Vdc supply can be connected to points A&B (positive) and C (negative). Two of these circuits, using ganged potentiometers at R2, R7, and Rll can be used for stereo applications. T1 is a 12-V 1-amp plug-in transformer. Notice that IC1 must be heatsinked. Power output is about 5 W. A 4` 2` 0.050` aluminum heatsink should be adequate.

2N3004 Audio Amplifier 25W

Transistors are used for current sources. Base drive for these transistors is derived from the main power supply VA, so that their collector current is proportional to the rail voltage. This feature holds the voltage on the cliff-amp collectors close to VA/2. The sensitivity of Iq to VA is about 3.4 mA/volt when VB is held constant; the sensitivity of Iq to VB is -15 mA/volt when VA is held constant. In a practical amplifier with a non-regulated supply, variations in power output will cause fluctuations in VA, but will not affect VB; therefore, having Iq increase slightly with power output will tend to compensate for the 3.4 mA/volt IqVa sensitivity. In the case of line voltage variations, since VA is about five times VB, the sensitivities tend to cancel, leaving a net sensitivity of about 2 mA/volt.

NE570 Attenuator circuit

A op amp and transistors Q1 and Q2 exponential converter to generate an exponential gain control current, which is introduced into the rectifier. A reference current of 150 pA, (15 V and RZO = lOO-k), is attenuated by a factor of two (6 dB) for each increase of tension in the control voltage. Capacitor C6 slows secure changes to a period of 20 IDS constant (C6 x IR) such that a sudden change in the control voltage will produce a gain change smooth sound. RI8 ensures that for control voltages of the circuit will go to great attentuation full.The rectifier bias current which would normally limit the gain reduction around 70 dB. RI6 attracts more courses of the rectifier. After about 50 dB of attentuation to -6 dB / V slope, with the increase in slope and the attenuation becomes much faster than the circuit to close completely at about 9 V control voltage. Al should be a low noise, high intensity, scanning speed, op. R13 and R14 in place around 0 V bias to the output.

AD844 Low-Distortion Amplifier/Compressor

Designers can build a 15-dB compressor with a miniature lamp and a current-feedback amplifier. The circuit possesses extremely low distortion at frequencies above the lamp`s thermal time constant. This means that distortion is negligible from audio frequencies to beyond 10 MHz. There`s also relatively little change in phase versus gain compared to other automatic gain-control circuits. Lastly, the circuit has many instrumentation, audio, and high-frequency applications as a result of its low distortion and small phase change. The AD844 op amp is a perfect fit for this application because it`s a current-feedback amplifier. Each stage of the circuit, U2, lamp, and feedback resistor compresses an ac signal by over 15 dB (see the figure). Cascading a number of stages delivers higher compression ranges. Op amp U1 operates as a unity-gain buffer to drive the input to the compressor. However, U1 is optional if a low-impedance signal source is used. The lamp`s resistance will increase with temperature, which reduces the ratio of resistor R3 to the resistance of the lamp. This ratio reduces the gain of U2. The lamp`s cold resistance should be greater than the input resistance of U2 (more than 50 ) for proper operation. The lamp`s resistance will change slightly for low input levels. Therefore, the ratio of R3 to the resistance of the lamp and the gain of U2 stays high.

LM380 mini Audio Amplifier

This be mini size power amplifier 2 watt OTL that use IC LM380. Be base readymade circuit for side sound work and the communication. Which use outside equipment adds least. The C6 can choose get many the value since 47uF to at 470uF which , have a voice good bass. The C3 use for decrease tall frequency or noise. It be valuable stay between 0.0047uF sections arrive at 0.047uF. And use to The 12V power supply (8V to 12V) from , car battery or the other.The Pin 3,4,5,10,11 legs and 12 soldered directly with copper side of PCB. Which use replace Heat sink The detail is other , see in the circuit.

LF351 Audio Amplifier

Ul, an FET op amp needs a bipolar voltage atpins 4 and 7 with a common ground for optimum gain. You can calculate the gain by dividing R2 by Rl. Zero-set balance can be had through pins i and 5 through R3. Put a voltmeter between pin 6 and ground and adjust R3 for zero voltage. Once you`ve established that, you can measure the ohmic resistance at each side of R3`s center tap and replace the potentiometer with fixed resistors. R6, R7, RS,and C3 forrn a tone control that will give you added bass boost, if needed;

LM1895N Audio Amplifier 1W

With 3-V to 9-V supplies, this amplifier can provide from 100-mW to 1-W output into a 4 and bandwidth is approximately 20 kHz @ 3 dB. This circuit is useful for low-power and battery applications.Drain is 80 mA @ 3 V or 270 mA @ 9 V at maximum signal conditions.