Check the listing for details. Audio Power HANDBOOK Blameless Design Class-B Dual Amplifier Board. Color: Green, Condition: New. Listed at 19.10 USD. Audio Power HANDBOOK Blameless Design Class-B Dual Amplifier Board Introductions:It's Blameless design Class-B amplifier. This power amplifier board is designed according to the defect-free amplifier class B power amplifier of DOUGLAS SELF's AMPLIFIER DESIGN, and does not use the most simplified circuit version in the book, but adopts the stronger performance CFP input stage version emphasized in the SELF book. circuit. This circuit is not included in the standard circuit on the following pages, but is described separately for better performance and lower distortion than the standard circuit. It's just that most of them are done against the standard circuits given by SELF. So I don't understand that the standard circuit of SELF is not an optimized circuit. And the components in the book are not the same as the components we actually use. So the operating point must be set separately and measured using APSYS. Instead of completely copying the circuit in the book, but the components are not the same, the result is not good, and the effect is not good. And LJM is based on the optimized cfp input stage .The triple-EF output stage structure circuit design in the book. And measured with APSYS TWO according to the components used by LJM. Then adjust the operating point to achieve excellent performance in practice. The power tube is matched with ONSEMI NJW0302G 0281G 150W 250V 15A transistor.The medium power driver tube uses KTA1659A KTC4370A Since Toshiba A1930 C5171 is discontinued, the decoupling capacitor uses Japanese original nichicon PW LOW ESR PW capacitor. The feedback capacitor adopts ULTRA LOW ESR Japanese original NICHICON HN/HZ gold capacitor. Parameters:Supply voltage range: DC +- 15V to DC + - 55VOutput power: 100W 8R, 200W 4R. (DC + - 45V)PCB size: 81*81MMTHD+N < 0.005%Input sensitivity: 1.5V 100W 8R RMS.Frequency response: 20HZ-20 KHZ -0.1DBQuiescent current :10MA (R1 resistance = 9K1). 50MA (R1 resistance=10K) Package:1pc Dual Blameless Design Class-B Amplifier Board