Any reason?

MaXiZ · 10th April 2005, 09:39 PM

Hi to all!
I've build various p3a amplifier.
But i've noticed that with some output it doesen't work..
Why?
I've build it with MJE4281 and MJF44H.
But with MJW22191/2 desen't seem any way to make it work! Why?

djk · 11th April 2005, 01:22 AM

Probably because none of those numbers are any good, not a one of them.

MaXiZ · 11th April 2005, 05:54 AM

Could u explaind a little bit more?
I'm not an electronic engeneer...
What mean?

edl · 11th April 2005, 12:32 PM

I have never heard about these transistors. Google neither.
I think they aren't in production.

Or maybe they are home-made transistors, fabricated by you?

MaXiZ · 11th April 2005, 04:22 PM

http://www.onsemi.com/pub/Collateral/MJF44H11-D.PDF
http://www.onsemi.com/pub/Collateral/MJW21192-D.PDF

MikeB · 11th April 2005, 04:33 PM

Could you explain "doesn't work" ?

Maybe you accidently swapped pnp and npn, that's a trap
with these devices, MJW21191 = pnp,MJW21192 = npn.
I don't see any reason why these shouldn't work, except that
they are not "state of the art"-devices.

Mike

MaXiZ · 11th April 2005, 04:40 PM

And what are the parameter that i should look to see if they're "state of the art" or not?

MikeB · 11th April 2005, 04:52 PM

The hfe-curve, 2nd breakdown (SOA), vbe-curve, maxdissipation,ft,
thermal resistance (junction to case) and so on.
A very good transistor is the mjl3281a/1302a for example.
The mjl21196/5 is also not bad.
Or take a look to the sanken 2sc2922/2sa1216.

Mike

MaXiZ · 11th April 2005, 07:56 PM

Quote:

Originally posted by MikeB
Could you explain "doesn't work" ?

Maybe you accidently swapped pnp and npn, that's a trap
with these devices, MJW21191 = pnp,MJW21192 = npn.
I don't see any reason why these shouldn't work, except that
they are not "state of the art"-devices.

Mike

MJW21191 at +v and mjw21192 at -v right?

darkfenriz · 11th April 2005, 08:06 PM

70-90% (EF output) probability otherwise

10th April 2005, 09:39 PM	#1
MaXiZ diyAudio Member Join Date: Jun 2003 Location: Italy	Any reason? Hi to all! I've build various p3a amplifier. But i've noticed that with some output it doesen't work.. Why? I've build it with MJE4281 and MJF44H. But with MJW22191/2 desen't seem any way to make it work! Why?

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11th April 2005, 01:22 AM	#2
djk diyAudio Member Join Date: Feb 2001 Location: USA	Probably because none of those numbers are any good, not a one of them.

11th April 2005, 05:54 AM	#3
MaXiZ diyAudio Member Join Date: Jun 2003 Location: Italy	Could u explaind a little bit more? I'm not an electronic engeneer... What mean?

11th April 2005, 12:32 PM	#4
edl diyAudio Member Join Date: Oct 2004	I have never heard about these transistors. Google neither. I think they aren't in production. Or maybe they are home-made transistors, fabricated by you?

11th April 2005, 04:22 PM	#5
MaXiZ diyAudio Member Join Date: Jun 2003 Location: Italy	http://www.onsemi.com/pub/Collateral/MJF44H11-D.PDF http://www.onsemi.com/pub/Collateral/MJW21192-D.PDF

11th April 2005, 04:33 PM	#6
MikeB diyAudio Member Join Date: Apr 2004 Location: Gütersloh	Could you explain "doesn't work" ? Maybe you accidently swapped pnp and npn, that's a trap with these devices, MJW21191 = pnp,MJW21192 = npn. I don't see any reason why these shouldn't work, except that they are not "state of the art"-devices. Mike

11th April 2005, 04:40 PM	#7
MaXiZ diyAudio Member Join Date: Jun 2003 Location: Italy	And what are the parameter that i should look to see if they're "state of the art" or not?

11th April 2005, 04:52 PM	#8
MikeB diyAudio Member Join Date: Apr 2004 Location: Gütersloh	The hfe-curve, 2nd breakdown (SOA), vbe-curve, maxdissipation,ft, thermal resistance (junction to case) and so on. A very good transistor is the mjl3281a/1302a for example. The mjl21196/5 is also not bad. Or take a look to the sanken 2sc2922/2sa1216. Mike

11th April 2005, 08:06 PM	#10
darkfenriz diyAudio Member Join Date: Jun 2004 Location: Warsaw	70-90% (EF output) probability otherwise

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