PART 1: onsemi MJH11019-MJH11020 ETI 470/480 Project

Part 1 of the Darlington Audio Power Amplifier Projects series originates from the classic Australian ETI 470/480 circuits, now re-crafted with modern onsemi MJH-series complementary Darlington topology. This project will feature a hybrid topology, combining the ETI 480’s front-end input stage with the Darlington output configuration of the ETI 470. These silicon power transistors from On Semiconductors are rated 15 amps, 150~250 volts and 150 watts—modernizes a classic circuit with minimal redesign and refined high fidelity. Featured Devices: PNP: MJH11017, MJH11019, MJH11021 NPN: MJH11018, MJH11020, MJH11022 A Tektronix TDS520D 500MHz oscilloscope, Siglent SDG805 5MHz waveform generator and an 8Ω dummy load were used to measure the power output of the prototype at 92.82 watts @ 8Ω and 157.44 watts @ 8Ω. The required rail power supply ranges from ±40VDC to ±55VDC. A QA400 audio analyzer measures the THD at @ –61.9 dB / 0.08007% , THD+N @ –61.5 dB / 0.0832% and SNR @72.4dB (20 kHz BW). For more information please email [email protected] or [email protected].