AMPLIFIER CIRCUITS DIAGRAM DRIVER
AMPLIFIER CIRCUITS DIAGRAM FULL
AMPLIFIER CIRCUITS DIAGRAM SERIES

: ) Remember that many modern op-amps have low power supply voltage ratings! The gain of those first two stages is set to only 34 each so that even slower op-amps will work fairly well but look for at least 1 MHz GBW. If you see the word 'audio' or 'distortion' anywhere in the manufacturer's data sheet, it's probably a good choice. The first two op-amps should be suitable for audio, like the MC33182, LM833 or many, many others.

AMPLIFIER CIRCUITS DIAGRAM FULL

Boy, it's tempting to use germanium diodes there! This little trick combined with the full gain and bandwidth of the op-amp being used to simply follow the input voltage results in very low distortion, even at full output and high frequency. The 1N4148 diodes reduce the op-amp output swing when the related transistor turns off the op-amp only has to swing a diode drop to maintain control over its negative input. In this way the quiescent current can be dropped to nearly zero with still excellent fidelity - perfect for small battery projects. For lower power applications, say a crystal radio amplifier, higher resistors could be used in place of the 1 ohm emitter resistors with a proportional decrease in the quiescent current. But too high of a value of resistance will cause the power transistors to get hot and the amplifier will be needlessly inefficient. Dropping to zero ohms won't hurt anything but might cause noticeable crossover distortion. The quiescent current is easily changed by adjusting that one resistor value for a very low value to conserve battery life or set around 10 mA for the best distortion. With a 15 volt supply, one can calculate that there's about 16 mV across the 220 ohm in the schematic and the op-amps force that voltage to appear across the two 1 ohm resistors, giving a bias current of about 8 mA (modified slightly by op-amp offset voltages). Each half of IC2 acts as a voltage-follower through its corresponding power transistor, holding the differential voltage across the two 1 ohm emitter resistors to a precise value set by the selected 220 ohm across the inputs. If you used single heat sink please use insulation between transistors and heat sink.The output stage uses a unique technique to stabilize the quiescent current without the traditional temperature-compensating diodes. Q1 and Q2 must be kept sufficiently cool, so it is mounted on a suitable heat sink.

AMPLIFIER CIRCUITS DIAGRAM SERIES

Volume control can be added to the circuit by connecting a 10KО© POT in series to the input of the amplifier. Power output of the amplifier Supply voltage (Vs)ДЎ0W is much enough for the day today home usage. Q1, Q4 and Q2, Q5 are complementary pairs, they make complementary darlington pairs.

AMPLIFIER CIRCUITS DIAGRAM DRIVER

Other transistors are 10mA small driver transistors. Q4 and Q5 must be between 100mA and 500mA driver transistors. Q1 and Q2 transistor must be between 3 and 5 amperes power transistors. There are eleven transistors, including four in the output stage. But this amplifier has very good sound quality. The entire circuit utilizes commonly available components and may be simply built over a general-purpose board. It is a simple amplifier to build, uses standard parts and is stable and reliable. This is a class AB transistor power amplifier. Discrete Class AB Transistor Audio Power Amplifier Circuit Diagram

Amplifier circuits diagram