Hello
I just finished my K8060 but it isn’t working properly. I did everything according to the manual. But with a few modifications. I’m using two heatsinks, one per transistor. And I’m powering it with a lab power supply (Velleman PS23023) at 2x30V. I connected 0V to GND, +30V to D3 (next to where it says +40V on the silk screen) and -30V to D5 (next to where it says -40V on the silk screen). I measured with a multimeter and had -32V on D5 and +32V on D3. Everything seemed OK, the LED lit up, I adjusted the bias (10.4mV, close enough 
). The power supply showed around 32V, 0.02A on both + and -30V. But when I connected a speaker (12" 4ohm subwoofer) I hit the current limit on the power supply (3 amps) on the +30V side. The -30V amp meter showed 0.02 amps. Also, the TIP142 got warm, but not the TIP 147. The funny thing is that it came sound from the speaker, a bit low but anyway. When I disconnected the speaker it all seemed normal again with 32V, 0.02A on both + and -30V.
It seemes as only the half with the TIP142 (the positive side) is working.
I’ve checked all the solderings and found nothing wrong. I even unsoldered both the TIPs and tested them with a simple circuit, as switches (they powered a lamp with a 1k resistor on the base). Both are still working.
Any ideas?
/Regards Rikard, Sweden