I believe the consensus is that they are other (less suitable) generic part numbers that have been marked "K170/J74".
In other words "fake".
In other words "fake".
When I have bought IR MOSFETs (a variety of part numbers) on AliExpress I noticed that most of the n-channel part numbers measured the same regardless of the part number. (Capacitances, as one example.) As if they bought one large batch of one part number and then labeled it with many part numbers. In some cases the device was larger than what the part number indicated. In most cases, however, the device behaved as a semiconductor die much smaller than indicated.
The p-channel devices all measured much smaller than they should have given the marked part number.
So if you are playing with an Arduino and want a MOSFET to turn on a relay that is one thing. But I would not buy them for SMPS or for any audio purpose.
The p-channel devices all measured much smaller than they should have given the marked part number.
So if you are playing with an Arduino and want a MOSFET to turn on a relay that is one thing. But I would not buy them for SMPS or for any audio purpose.
Some MT-200 devices out of unknown source were given to me. Looking good to my eyes, don't they?
The 2SA1930s on your last picture have a slightly different package than the 2SC5171s whose packages look authentic to me. The 1930s might be DIYI semiconductor parts with faked Toshiba markings. Or maybe Toshiba changed the package at some point, I don't know.
Edit: The legs of the 2SA1930s also don't look like Toshiba to me.
Edit: The legs of the 2SA1930s also don't look like Toshiba to me.
I have the same question as you said, A1930 suspicious, but the lot code is Toshiba format and that the only way I think it's original otherwise seems off
Can someone recommend a 60w-100w amplifier for my NJW0281G NJW0302G, but please share Details about tested designs and layout, which are available on this platform
I thought i should share some photo(which is currently available in my phone) of original transistors for diyaudio community.....
You unlock all your toys with skin-prints. However it was recently found that a leading phone brand would un-lock with ANY fingerprint. Saves us the trouble of cropping-out and printing fingers found on-line.
Well friend
Someone, somewhere is always looking at your activities, no matter the nature of things you do.
And I don't worry about scams, identity theft or even cyberbullying. I don't care.
There is nothing to hide, I don't worry about privacy, in this world nothing is private anymore.
Someone, somewhere is always looking at your activities, no matter the nature of things you do.
And I don't worry about scams, identity theft or even cyberbullying. I don't care.