Use twin FET input transistors.
Use imported original NE5532 as preamplifier. DC Servo DC SERVER circuit.
The output power tube can be matched with the original KEC KTB817 and KTD1047 pairs of tubes.
Supply voltage: +- 25V to +- 55V
Output power: Max 150W/ 8R
Voltage Gain: 90
Frequency response: 20HZ -0.05DB. 20KHZ-0.15DB.
THD+N: < 0.02% 50W/8R
PCB size: 153*42MM (mono)
Note：
Assembled Board：have tested it well ！
