Topology Federmann, HQQF-55 ...

[Federmann]

Originally Posted by PMA

…This would result both in poor reliability and poor linearity.

I did many years in manufacturing semiconductors. I developed measuring methods and testers, to which measured the hundreds of millions of semiconductors. I know very well how to measure and select transistors.

[Upupa Epops]

Let it be, Pavel...F. probably did not know, that BUZ 906 is lateral type, which have much lower forward transconductance, much narrower tolerance gate threshold voltage and positive Tc..... mosfets are muchness, no problem for him....

[PMA]

Well said, syn08. I can even digest your attitude to us, though we have no commercial issues with Federmann, just technical. At least you seem to me to be an honest man.

[Iain McNeill]

OK guys, get back on topic and stop the offensive language or there will be bin time.

[jacco vermeulen]

Originally Posted by PMA

I have a stock of some 150 + 150 2SK413/2SJ118 Hitachi MOSFET devices.

Pavel,
i knew there was something wrong with you.

[stinius]

Originally Posted by PMA

Well said, syn08. I can even digest your attitude to us, though we have no commercial issues with Federmann, just technical. At least you seem to me to be an honest man.

PMA

It seems like syn08’s post is deleted, but I read it and I fully agree with what he was writing.

BTW it’s good to see that you think syn08 is an honest man.

Cheers
stinius

[Upupa Epops]

I also fully agree with syn08....

[PMA]

In case it is a lateral, it has also MUCH higher Rdson, and serial resistors are not necessarily needed.

[syn08]

Originally Posted by PMA

In case it is a lateral, it has also MUCH higher Rdson, and serial resistors are not necessarily needed.

That's a secondary reason, if at all. The main reason is that laterals, also like JFETs, do not hog current. If one is drawing significantly more current than the counterparts, it gets hot, transconductance goes down, and the currents are, more or less, self balancing. This will preclude any physical damages, but is still not recommended for optimum performance.

BTW, I don't give a FF about posts being deleted. What's really worrysome is moderators allowing designs that may potentially damage property and health. Perhaps some moderators never had a chance to watch an overheating and blowing +/-80V 500W amp, it's never to late, just build this one and watch the fireworks, from a safe distance.

[PMA]

Totally agreed. All of us (you, Upupa, stinius, me and others) know what is a multiple pair IRF240/9240 without source resistors like. It would explode, as you have said, especially if amplifier is said to be 2 x 500W rated.