pcb realized on JC3 scheme, obtainable power: 25watt / 8ohm RMS, 40watt / 4ohm RMS, transformer used: 20 + 20 vac 350VA, the assembly includes 3 pairs of final transistors for a better driving with low impedance loads .
1)set VR1 to reach across R5 = 0,80VDC
2)set VR3 to total current absorption =1,2A.
3)set VR2 for 0v. output offset