Introduction
Are you ready to take your audio setup to the next level? Introducing the 60-watt Mini Crescendo Amplifier Circuit tutorial! In this step-by-step guide, we’ll show you how to assemble your own powerful and compact amplifier that delivers 60 watts of crisp, clear sound.
This tutorial is perfect for anyone looking to build their own high-quality audio system. With easy-to-follow instructions and the right components, you’ll be on your way to creating an amplifier that packs a punch in no time. So grab your tools, and let’s get started!
Circuit Diagram
Construction
- Construct the circuit as close to the diagram as possible for the best results
- T15 and T16 require a common heat sink with a thermal resistance of 1.5-2°C/W, don’t forget to use mica washers
- T13 and T14 should have separate heat sinks with a thermal resistance of about 12°C/W
- Although temperature changes do not significantly impact the output stage quiescent current, we recommend you to thermally couple T9 and T11 and T10 and T12 by attaching their flat surfaces together for added stability.
Working Explanation
The 60-watt Mini Crescendo Amplifier Circuit is designed with two type 2N3055 power transistors in the output stage for their reliability. The output stage is symmetrical, not asymmetrical, as some may think. The upper half of the output stage contains NPN super transistor T11/T13/T15, while the lower half includes PNP super transistor T12/T14/T16. The symmetry is maintained throughout the amplifier with double differential amplifiers T1/T2 and T3/T4, current sources T5 and T6, and driver stages T7 and T8.
The amplifier provides 40 W of output power into 8 Ω or 60 W into 4 Ω with a frequency range of 20Hz-20kHz and a distortion not exceeding 0.01%. The maximum power is 45 W into 8Ω and 65 W into 4Ω before clipping. The input sensitivity is 800(850) mVeff for 40(45) W into 8 Ω and 700 (725) mVeff for 60 (65) W into 4Ω. The frequency response stays within 1 dB in the range of 15 Hz-100 kHz. The quiescent current is low, around 25-50 mA, thanks to the high current amplification of over 200,000. P1 sets the quiescent current by connecting a universal meter across the R25-R30 chain of resistors and measuring the voltage equivalent to 50 mA current, which is 33 mV.
Final Words
The 60 Watt Mini Crescendo Amplifier Circuit is a reliable, high-performance solution. With a symmetrical design featuring complementary NPN and PNP transistors, the circuit delivers up to 65 watts of power into 4Ω with a distortion not exceeding 0.01%. The low quiescent current and small cross-over distortion make this circuit an excellent choice for audio enthusiasts. Try this circuit, and feel free to ask questions if you have any!
