Offtopic
The lousy old uA741 opamp is 40 years old. It might be fine in an inverter circuit.
I think the 3rd world and 5th world are getting it now. The 4th world gets it next year.
OFFTOPIC: hahaha 741 opamp just arriving here!? I admire very much your experience, and appreciate the number of times you got me out of trouble, Audioguru. But I really dissagree the repetitive commentaries that you make about first, second, third, four, five, twenty, one hundred world. It's a very unreal clasiffication, on social topics but also electronics.
I'm not living on a "first" or "second" world country, but I can get any kind of electronic component at a rasonable price or even cheaper, on any electronics store. I'm making the comparison with San Francisco CA, where I also lived.
Even better, is much more easier to find qualified technicians and spare parts, because the idea of "Use and if damaged, simply throw away" is not so common than on the first world countries.
I don't know about poorer and less fortunate countries, but generalizing is not a good thing. As fake as "Africa is only wild animals, Australia Kangaroos, Russia snow"
I hope you take this suggestion on a positive way