MJE340 MJE350 detalied data, more than the datasheet

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MJE340/350, does anybody have more data about these? I have looked at Thomson and ON. They say nothing about fT, caps or other frequency properties.

The current gain is >30, typ 240. Does anybody know what the real life value is (in average)?

I'm thinking of testing these transistors in my QRV-02 headphone amp. Now I use BD139, 140, good old work horses.
 
Christer said:
You haven't considered the newer Toshiba drivers 2SA1837 and 2SC4793? They have a typ. fT of 100MHz and are available from Elfa, although a bit more expensive than the MJEs. See http://www.elfa.se/elfa/produkter/se/20/2022252.htm

I have considered using these instead of 2SB649/2SD669 which
are now discontinued from Elfa (not from the manufacturer, though).

My interest was only "do they work". I have those and they are like replacements for BF471/472, high power amp drivers.

The last question: No, my goal is to use easy-to-get-parts, in Sweden Elfa. But since the output stage aren't very special, there are lots of room for experiment.
 
peranders said:
MJE340/350, does anybody have more data about these? I have looked at Thomson and ON. They say nothing about fT, caps or other frequency properties.

The current gain is >30, typ 240. Does anybody know what the real life value is (in average)?

I'm thinking of testing these transistors in my QRV-02 headphone amp. Now I use BD139, 140, good old work horses.
peranders,
As they don't give Ft it is probably < 3MHz i.e. slow or general purpose transistor.;)
 
Peranders,

I have measured Ft for this transistors some years ago.

Results were 20 to 30 Mhz for MJE340, but 8 to 12 for MJE350.
They work very well as drivers for Mosfets, but only as "up" transistor in cascode configuration. Or as constant-current source or sink.


Regards, Pierre Lacombe.
 
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