Changes to K8060 to produce 250W RMS into 8R which some might find interesting.
This involves increasing supply valtage and upgrading various components.
Obviously will void limited warranty.
C12, C13 4700uf 80V (Nichicon type fits on board)
C7, C8 100nF 100V ceramic
C6 47nF 100V ceramic
C4, C5 470pF ceramic
C10 100uF 63V or 100V electrolytic
T3 ZTX857 glued to small heatsink (watch pinout as different from BC639)
D5, D5, D4, D3 P600D or bridge rec
R13 4K7 2W
R12 1K5 0.6W
R8 3K3 0.6W
R11 8K2 0.6W
R6 82R (higher than R16 as T5 sees much lower impedance on current limit)
R10 10R 0.6W
R19, R20 0.22R 5W
Heatsinks should be forced air cooled
Transformer 50-0-50V @ 500VA will power two K8060’s (Maplin)
Earthing between two boards should be strapped together with very low impedance braid/wire to avoid hum.
Use 40W bulb in series with mains supply to test and check 0V on LS+ before connecting speaker.
RMS power was measured using burst sinewave test signal. Should be OK into 4R load but not short circuit.