homemodder said:
The Japanese manufacturers likely made a lot of private deals amongst themselves.
Original A1075/C2525 RET manufacture was by Fujitsu.
Surprise surprise : Toshiba releases the higher powered A1095/C2565 years after the introduction of the Fujitsu devices, and for some reason the series numbers look like close cousins.
The US industry never had an us-against-them mindset.
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Nice Jacco, You seem to be able to dig up these pics from I have no idea where, a semiconductor museam perhaps ???
The us was not against them in the sense of the word, but they sure had the +buy american its better+ policy for financial reasons and for years had policy of exporting their goods and claiming excellence but had trading restrictions for preventing goods with superior characteristics being imported by claiming they were inferior. They are learning the hard facts of life at the moment.
Some of their industries still try to do this, look at their car industry, highly unefficient, inferior quality and retro design characteristics are still advertised as being better. ???? What :bs:
BTW who or what is the fred campain, or should I rather not ask🙂
The us was not against them in the sense of the word, but they sure had the +buy american its better+ policy for financial reasons and for years had policy of exporting their goods and claiming excellence but had trading restrictions for preventing goods with superior characteristics being imported by claiming they were inferior. They are learning the hard facts of life at the moment.
Some of their industries still try to do this, look at their car industry, highly unefficient, inferior quality and retro design characteristics are still advertised as being better. ???? What :bs:
BTW who or what is the fred campain, or should I rather not ask🙂
I call it at home with a cold.
As i still spend way more on commercial audio gear than on electronic parts i haven't reached the pathetic stage, yet.
I merely meant technical exchange/interaction.
A factor for the US semi-industry to be catching up looks to be that the Japanese manufacturers seem to be loosing their interest in discrete semi-conductor parts, high power components in particular.
Just some rebellious support for my friend Phreddie-D.
As i still spend way more on commercial audio gear than on electronic parts i haven't reached the pathetic stage, yet.
I merely meant technical exchange/interaction.
A factor for the US semi-industry to be catching up looks to be that the Japanese manufacturers seem to be loosing their interest in discrete semi-conductor parts, high power components in particular.
Just some rebellious support for my friend Phreddie-D.
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Just a followup:
A good replacement for discontinued 2SA968/2SC2238 pair is 2SA1930/2SC5171. Their hfe-Ic profile is really, really flat. The pair is used in many modern commercial amplifiers, too. They are rated for 180Vcbo and 2A Ic.
Enjoy!
satoru
A good replacement for discontinued 2SA968/2SC2238 pair is 2SA1930/2SC5171. Their hfe-Ic profile is really, really flat. The pair is used in many modern commercial amplifiers, too. They are rated for 180Vcbo and 2A Ic.
Enjoy!
satoru
the 968 can take 11W @ 50Vce, whereas the 1930 can take 6W @ 50Vce.
Hardly comparable in most amplifiers running on +-50Vdc supplies.
The To126 packaged 2sb649/d669 can take 15W @ 50Vce.
Hardly comparable in most amplifiers running on +-50Vdc supplies.
The To126 packaged 2sb649/d669 can take 15W @ 50Vce.
Don't judge a book by it's color.
Toshiba changed the logo for all of their devices in the later production phase, and the cases to All-Afro.
Only way to find out is to measure the things with a capacitance meter. (there are schematics and kits for simple cap meters on the web)
Toshiba changed the logo for all of their devices in the later production phase, and the cases to All-Afro.
Only way to find out is to measure the things with a capacitance meter. (there are schematics and kits for simple cap meters on the web)
I don't have one of those handy at the moment, so I was hoping someone here could help.
I don't have a picture of the 968s yet. Not sure what they are, but they have a K A968 on them.
I don't have a picture of the 968s yet. Not sure what they are, but they have a K A968 on them.
I checked Toshiba's web site and the replacement for 2SA968/2SC2238 pair is 2SA1837/2SC4793 which has the same SOA. As pointed before by AndrewT, 2SA1930/2SC5171 pair doesn't have comparable SOA to 2SA968/2SC2238 pair. My bad...
The logo on Filburt's 2SC2238 is the same as the one on all Toshiba devices I purchased in Japan in recent years. My 20 years old 2SC2238 (and others) have the logo same as what jacco posted. One concern about Filburt's 2SC2238 is the order of markings:
Many of TO-220 devices (if not all), like 2SA1837/2SC4793, has markings as follows:
T (new Toshiba logo, as seen in Filburt's image)
Device name (with omission of "2S")
Lot #
Line for Pb free device
I only checked the spec sheets and acutual devices for a couple of TO-220 devices but all were the same. Does anybody know more on this issue??
Thanks!
The logo on Filburt's 2SC2238 is the same as the one on all Toshiba devices I purchased in Japan in recent years. My 20 years old 2SC2238 (and others) have the logo same as what jacco posted. One concern about Filburt's 2SC2238 is the order of markings:
Many of TO-220 devices (if not all), like 2SA1837/2SC4793, has markings as follows:
T (new Toshiba logo, as seen in Filburt's image)
Device name (with omission of "2S")
Lot #
Line for Pb free device
I only checked the spec sheets and acutual devices for a couple of TO-220 devices but all were the same. Does anybody know more on this issue??
Thanks!
Sing a Gershwin tune :It ain't necessarily so.
Could be a Korean KEC manufacture version, Toshiba has a stake there and some of the oldies are manufactured legit in Korea nowadays.
I haven't seen a KEC 2SA968 version face to face yet though.
Could be a Korean KEC manufacture version, Toshiba has a stake there and some of the oldies are manufactured legit in Korea nowadays.
I haven't seen a KEC 2SA968 version face to face yet though.
Hi,
2SC2238 can be genuine with some luck.
2SA968 may be KEC, FEC or SEC (but not NEC) who knows.
singin` Everybody Loves Somebody Sometimes...
😀
2SC2238 can be genuine with some luck.
2SA968 may be KEC, FEC or SEC (but not NEC) who knows.
singin` Everybody Loves Somebody Sometimes...
😀
Filburt,
no, Q10/11 set the main properties of the output stage.
Very nice design indeed. I just cannot understand why 2SC2238/2SA968 were chosen since 2SC5171/2SA1930 are better (if genuine). In any case, I would use large heat sinks.
no, Q10/11 set the main properties of the output stage.
Very nice design indeed. I just cannot understand why 2SC2238/2SA968 were chosen since 2SC5171/2SA1930 are better (if genuine). In any case, I would use large heat sinks.
Better how so? Considering the myriad of contradicting statements one sees when trying to get an idea of what is a good choice to use, I'd say most choices are less-than-obvious. I tried my best to pick something appropriate 🙁
Filburt,
sorry, I did not mean to blame you, just was wondering why 2SC2238/2SA968 were originally chosen here. 2SC5171/2SA1930 are faster, have lower Cob, widely preferred and surely better sounding. On the other hand, with 2SC2238/2SA968 you don´t risk running into oscillation problem.
sorry, I did not mean to blame you, just was wondering why 2SC2238/2SA968 were originally chosen here. 2SC5171/2SA1930 are faster, have lower Cob, widely preferred and surely better sounding. On the other hand, with 2SC2238/2SA968 you don´t risk running into oscillation problem.
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These are original Toshiba 2SC2238/2SA968.
The newer 2SC4793/2SA1837 are very similar. They spot the updated logo. No longer the old "T"
The newer 2SC4793/2SA1837 are very similar. They spot the updated logo. No longer the old "T"
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