K8060 keeps blowing up ! Is it a bad December 2020 Batch?

Hi everyone,

I have been using the K8060 for over 10 years now, and I made about 110 modules so far, without a failure, but this month, on my last December batch I just got 3 Amplifier failures !!!???

The amp is running fine and suddenly, after a few minutes of being powered ON, both of the TIP transistors suddenly short !? (it’s always an Emetter-Collector short !?)

That is of course with no signal applied to the input and a PSU AC feed of 39 Volts.

What is going on ?

Please help and let me know if Velleman has had trouble with the K8060 Amp module in December and January 2021 this month ?

Thank you.