** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **
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Re: ** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **

by Brassteacher on Sun Feb 20, 2011 7:36 pm

Small update on the "real" C1583 transistors with the code 52G. The ones I have, as I posted before, are in fact real, but are apparently factory seconds or re-marked NTE42 transistors (NTE42 is the listed NTE sub for C1583). The "G" on the end of the code is the Hfe rating, and G-rated C1583s should have a minimum Hfe of 400. The ones I had measured in the mid 300's, so they appear to be rejects. However, the original TB-303 used F-rated C1583s, and those have Hfe ratings between 250-500. Long story short, if you get a C1583 52G and it tests as a dual NPN with the correct pinout, and the Hfe measurement is between 250-500, go ahead and use it! Just put the highest-measuring one in the Q21 slot.

As always, if in doubt, throw it out (or go shove it in the ear of the person who sold it to you, legs first :mrgreen: ).
Don Taylor, a.k.a. Brassteacher
"Jack of all trades, master of none, proficient at even fewer..."
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Re: ** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **

by decoder23 on Mon Feb 21, 2011 2:03 pm

well, i just wanted to make some tests, if the sound changes, when i swap my 2sc1583 trannies. i put them in q26 and i only heard clicks, no notes anymore.
so i tested them in my multimeter and they were pnp instead of npn, hfe around 400...
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Re: ** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **

by Brassteacher on Thu Feb 24, 2011 1:02 am

decoder23 wrote:well, i just wanted to make some tests, if the sound changes, when i swap my 2sc1583 trannies. i put them in q26 and i only heard clicks, no notes anymore.
so i tested them in my multimeter and they were pnp instead of npn, hfe around 400...


Oh, I have no doubt there are fake ones with that datecode out there, I'm just making the point that they all are not fake, and are worth testing before just throwing away a C1583 with a 52G suffix.

If the fake ones are common-emitter, PNP transistors, then they are most likely really a re-marked 2SA798, which is also a transistor that is worth having around. Oddly enough, they sometimes cost more than C1583, and they were quite common in older Korg analog synths, especially the Poly-6, and the Poly-61. So, if anybody has these, they are probably something that someone will have a use for, so you may be able to recover at least some of your $$.
Don Taylor, a.k.a. Brassteacher
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Re: ** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **

by Reliz on Wed Oct 05, 2011 1:50 am

I orderd some 2N3055 transistors and i tryed them out.The thing was not working as it should.So i tested it.an light 100mA load no problem.Then an short thurn at a 10A load.But then then colector and emiter got shorted! Its rated at 15A continues how cod it blow.The thing blows at 3A. Somting is defently not right here.
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Re: ** WARNING - Fake 2SC1583 Transistors 'C1583' batch '52G' **

by Luap on Wed Oct 05, 2011 9:46 am

Reliz wrote:I orderd some 2N3055 transistors and i tryed them out.The thing was not working as it should.So i tested it.an light 100mA load no problem.Then an short thurn at a 10A load.But then then colector and emiter got shorted! Its rated at 15A continues how cod it blow.The thing blows at 3A. Somting is defently not right here.


Seriously, what?
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