Vector Viper wrote:

If you use a sub par 2SC4927 , this is what happens.

That is INSANE! a part of a certain number should be the all the same,
regardless of who makes them...why oh why are there sub par parts....they
are cheaper, of course...

I remember way too many instances where this sort of thing happened. Crown
audio amps for one example used to spec _only_ Motorola brand 2N3055 output
transistors, anything else would void the warranty! And then there's all
those mfrs who specify that their part is a given part number, but
"selected"... SELECTED FOR WHAT? Altec was a great one for this, just
about every single semiconductor in much of their stuff that I got service
info on was labeled like that.

Why do they have to design stuff like this? Grrr....