Hello every one
I have a Classe ca 150 with some burned output transistors and also have some new MJL transistors laying around. is it just to swap out the 2SC4029 and 2SA1553 to MJL21194G and MJL21193G ??
the service manual is attached
I have a Classe ca 150 with some burned output transistors and also have some new MJL transistors laying around. is it just to swap out the 2SC4029 and 2SA1553 to MJL21194G and MJL21193G ??
the service manual is attached
Attachments
2SC/2SA are considerably faster (ft > 30 MHz nominal ) output transistors than the MJLs (ft = 4 MHz) , look at the ft vs Ic diagrams.
Their hfe is about 50% higher and COB half of the MJLs.
Id say it makes a pretty poor replacement.
I say 2SA1943/2SC5200 are a better replacement. If they fit physically, I have not checked pinout and package sizes (I think one is TO-284 and the other TOP3L) If you dont go abroad, for sorucing:
https://www.electrokit.com/en/2sa1943-to-264-pnp-230v-15a
https://www.electrokit.com/en/2sc5200-to-264-npn-230v-15a
Or
https://lukaseparts.se/product-category/diy-komponenter/transistorer/bipolara-bjt/effekttransistorer
Th
Their hfe is about 50% higher and COB half of the MJLs.
Id say it makes a pretty poor replacement.
I say 2SA1943/2SC5200 are a better replacement. If they fit physically, I have not checked pinout and package sizes (I think one is TO-284 and the other TOP3L) If you dont go abroad, for sorucing:
https://www.electrokit.com/en/2sa1943-to-264-pnp-230v-15a
https://www.electrokit.com/en/2sc5200-to-264-npn-230v-15a
Or
https://lukaseparts.se/product-category/diy-komponenter/transistorer/bipolara-bjt/effekttransistorer
Th
yep that is all correct. thishibao ahve a very good ft and less Cob then others.
if you need more power then 15oW 2SC5200 you can use the big brothers --> 2SC5359_O -180W
kr
chris
if you need more power then 15oW 2SC5200 you can use the big brothers --> 2SC5359_O -180W
kr
chris
The service manual shows the amp originally having MJL21193/4. Yours came with C4029/A1553?
Those Toshiba parts are faster, but not as high as devices like the C5200. With 3 output pairs on those voltages I’d be going for the most rugged devices available, not pushing the fT. Drivers are hefty mosfets, which will have no problem pushing charge in and out of the output transistor bases. I’d be more inclined to go back to the MJL21194 specified, or the MJL3281 as the higher speed alternative.
Those Toshiba parts are faster, but not as high as devices like the C5200. With 3 output pairs on those voltages I’d be going for the most rugged devices available, not pushing the fT. Drivers are hefty mosfets, which will have no problem pushing charge in and out of the output transistor bases. I’d be more inclined to go back to the MJL21194 specified, or the MJL3281 as the higher speed alternative.
Aha...i understand . then it is clear for me to keep the OPS transitor "slow" but deliver at 120V or bigger the better current availability at higher current.
as i read in a other thread the thosibas cannot keep the higher current as good as the MJL-parts
thosiba
thx
chris
as i read in a other thread the thosibas cannot keep the higher current as good as the MJL-parts
thosiba
thx
chris
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wg ski, I didnt check the manual
That changes the game considera ly.
If it orignially was designed for the 21193/94 I would absolutely not switch to faster Toshibas or any brand with almost a magnitude higher Ft , atleast not without more evaluation about stability etc.
21193/4 also are very rugged.
That changes the game considera ly.
If it orignially was designed for the 21193/94 I would absolutely not switch to faster Toshibas or any brand with almost a magnitude higher Ft , atleast not without more evaluation about stability etc.
21193/4 also are very rugged.