New transistor source

I purchased 60 each of the KEC 1381/3503 and 20 each 1837/4793and KTB1369-Y/KTD2061-Y I could not resist testing them to see how well their HFE range matched and i can say they measured well within their spec and numbers part to part was closer than most of the parts I have bought over the years from Many sources. The 1837/4793 was not marked with Y hfe designation but they all measured within that spec the lowest was 150 highest was 170 across PNP/NPN the Koreans seem to have their process control very well structured and it shows in the Parts that i purchased. This is 5th time i have bought parts from Profusion and I would not hesitate to say they are Legit place to buy parts and they ship fast I used the 9 dollar international shipping and had my parts in a week from payment not bad at all it sure beats paying 35 dollars for 3 day international shipping. The parts that surprised me was KTB1369/KTD2061 they measured in 150 range for a 2 amp driver with specs similar to sanken 2sc4883/2SA1859 these look perfect when you want a single driver for 3 or more pairs of output devices and fills in the blank space when you want a faster driver than the MJE150XX from Onsemi. Anyone on the fence because they are worried about quality from Profusion i would in my experience say that they are a Trusted Source
This is correct - have observe the same.
 
According to the KEC data sheet, curves look more like 2SC3281 than 2SC5200. So what’s true?

If all these recent additions to the portfolios of the 3rd party semi houses live up to their billing, it will be a game changer. The prices cannot be ignored, especially for an OEM. Authorized distributors in the US cropping up? Mouser stocking them? Do they have agreements with ON, Toshiba, ST that prohibits this? Will the original makers fight them in court or just exit the markets? Will it make getting quality audio semis easier or harder for US (hobbyist and small commercial users) to get in the long run?

I’m tempted to just go ahead and order two tubes of the NPN and PNP. $150 experiment. I did find 11 more transformers I can re-wind. As if I don’t have enough to do….
 
  • Like
Reactions: Mainframe
Look at Digi-Key recently offering EVVO brand semis.
KEC is not a recent addition they have been doing it for years, just now that they are being made more available through a authorized distributor other than in Asia and OEM
Profusion adequately meets the needs selling KEC brand . My order managed to even evade taxes so that covers the shipping cost = win win
 
Last edited:
  • Like
Reactions: AudioPackrat
KEC is not a recent addition but their 150 watt power transistors ARE. They have been making small signal and driver types for years but 150W triple diffused parts are new territory. If they can make them handle full power at 70 volts like Toshiba used to they really will be getting somewhere.

I’ve seen a lot of inconsistencies on Evvo data sheets. We’ll see if they last.
 
  • Like
Reactions: Mainframe
Hammer to fall... Comparison between Toshiba and KEC. (Found in another forum)
 

Attachments

  • 5200.jpg
    5200.jpg
    271.4 KB · Views: 155
I bought 100 KTB1369/KTD2061 pairs from Profusiion in two lots of 50 at different times and the hfes were all closely clustered around 210, with a few higher outliers. Don't know whether I've just been lucky but all the KEC complementary pairs I've got from Profusion have been pretty good matches. Or maybe they've got their process down to a fine art.
 
  • Like
Reactions: AudioPackrat
The conclusion is obvious - it is constructed properly. Different size bolt holes in the leadframe would only be an issue if it claimed to be a Toshiba part. It’s made of copper so it has the proper thermal properties. The die is big enough, which makes 150W short term dissipation possible. And the encapsulation properly adheres to the die - since it shears off in the same way that all “good” ones do. No white goop. So it will withstand moisture to the same extent as originals.
 
The conclusion is obvious - it is constructed properly. Different size bolt holes in the leadframe would only be an issue if it claimed to be a Toshiba part. It’s made of copper so it has the proper thermal properties. The die is big enough, which makes 150W short term dissipation possible. And the encapsulation properly adheres to the die - since it shears off in the same way that all “good” ones do. No white goop. So it will withstand moisture to the same extent as originals.

Well if you think they are constructed properly, good luck to you. The chips are not even straight or centered in one instance. And as I said before, there isn't the same clearance between the collector and the screw as the Toshiba parts. My conclusion, Toshiba parts are superior to KEC in this instance. Details matter.