Re: k series amp trannies
Any idea if the transistors are "real" toshibas or fakes?
Cheers!
audiomachines said:
Any idea if the transistors are "real" toshibas or fakes?
Cheers!
audiomachines said:
there is a guy here named ferdz, and also at pinoydvd, who is at 24 very well versed with protel pcb design software, i believe it won't be hard to convince him to design the pcb for us should there be enough interest on it.
Re: Re: k series amp trannies
unlless you get them from the factory, it would be very hard to tell...
clem_o said:
unlless you get them from the factory, it would be very hard to tell...
Hi Tony,
The Base to Emitter junction capacitance appears to be a good indicator of 'authenticity'. The real ones have a higher BE capacitance, due to larger die size.... usually a few nF. Specifics for the 2SC5200 etc I don't have however...
Thread is here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=82638
Also, I guess if the transistors keep blowing up then its a good indication that they are fake... hehehehe!
Cheers
Clem
The Base to Emitter junction capacitance appears to be a good indicator of 'authenticity'. The real ones have a higher BE capacitance, due to larger die size.... usually a few nF. Specifics for the 2SC5200 etc I don't have however...
Thread is here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=82638
Also, I guess if the transistors keep blowing up then its a good indication that they are fake... hehehehe!
Cheers
Clem
yes, but i would'nt be too quick to call that, you can easily fry genuine transistors if the biasing is not right. i've learned that repairing Sansui amps....Sansunog is how we called those amps from the late 80' to early 90's....😀
Haha, nice name.
Re frying up transistors - true, however if the bias is set right and isn't drifting YET the thing transistors keep blowing.. We had an Onkyo amplifier with those particular symptoms. Came in with blown outputs, bought a set of trannies from Raon, put them in, check bias. Everything ok, even powering speakers for a while. Once you push the amp to high power levels, poof... Happened several times, and that's actually what started us guessing that we had fakes!
Cheers!
Re frying up transistors - true, however if the bias is set right and isn't drifting YET the thing transistors keep blowing.. We had an Onkyo amplifier with those particular symptoms. Came in with blown outputs, bought a set of trannies from Raon, put them in, check bias. Everything ok, even powering speakers for a while. Once you push the amp to high power levels, poof... Happened several times, and that's actually what started us guessing that we had fakes!
Cheers!
yes, that would be an unmistakeable analysis....😀 that is why i prefer to buy those junked boards with parts, than buy new trannies from say, DEECO... oriental, newport and liamco seem to be reliable though...
Original toshiba transistors can be bought at DECIBEZ (Ronquillo St.)The A1943 and C5200 is priced at 150 each.You can buy cheaper transistors in RAON but it depends on their stock sometimes good more often fakes.
Hi MGR,
That's a bargain if those are real!!
I'm waiting for anatech if he can give me some capacitance readings on known original devices. When I have that info I'll bring a capacitance meter to Raon and check these out!
Cheers!
That's a bargain if those are real!!
I'm waiting for anatech if he can give me some capacitance readings on known original devices. When I have that info I'll bring a capacitance meter to Raon and check these out!
Cheers!
I have tested this transistors using +- 90 supplies into a 4 ohm load with no failures.Actual test into my friends mobile rental amps for 1 year with o failures.In my research I bought from at least 5 different stores in RAON most of them failed.And yes capacitance is a good way to separate the genuine from the fakes.I also bought from digikey and compared it to the one I bought in Ronquillo they are the same in quality.
Hi MGR,
That's great!!! Thanks for the tip too - now perhaps that gives some more impetus to go ahead and build a good amp!
Cheers
That's great!!! Thanks for the tip too - now perhaps that gives some more impetus to go ahead and build a good amp!
Cheers
hi clem_o,
will you be using DMM for this tests.
well we are all drowned with fakes these days..
so thats why for my projects I have to spend so much for
Onsemi's MJL's
macweb
will you be using DMM for this tests.
well we are all drowned with fakes these days..
so thats why for my projects I have to spend so much for
Onsemi's MJL's
macweb
fake op
hello guy,
fyi, 2sc5200, 2ca1943 absolutely fake if the part number can easy to read. i bought in eleshop raon. when I powered it to my amp my fuse blown. just for curious I cracked it and I found that the die is undersized.
there is one transistor the part number is hard to read, but no idea if it is genuine. according to the store (eglo electronics supply) it is original daw. I dont think so the price is cheap php 90. huh
rlg 😉 😉 😉
hello guy,
fyi, 2sc5200, 2ca1943 absolutely fake if the part number can easy to read. i bought in eleshop raon. when I powered it to my amp my fuse blown. just for curious I cracked it and I found that the die is undersized.
there is one transistor the part number is hard to read, but no idea if it is genuine. according to the store (eglo electronics supply) it is original daw. I dont think so the price is cheap php 90. huh
rlg 😉 😉 😉
hi rlg_200,
are there Onsemi power outputs available in your place
MJL4302/MJL4281 or other related trannies....?
macweb
are there Onsemi power outputs available in your place
MJL4302/MJL4281 or other related trannies....?
macweb
hienrich,
mjl4302/mjl4281, as know this device is high voltage 350 volts vce I think, it uses by ESP high end, here in Raon alexan not yet available out of stock daw, But u can go to mjl21193/94 it is almost the same characteristics 250 volt vce, (onsemi). php 430/pc. in alexan. power op BJT will sell in alexan are onsime and fairchild.
rlg 😉
mjl4302/mjl4281, as know this device is high voltage 350 volts vce I think, it uses by ESP high end, here in Raon alexan not yet available out of stock daw, But u can go to mjl21193/94 it is almost the same characteristics 250 volt vce, (onsemi). php 430/pc. in alexan. power op BJT will sell in alexan are onsime and fairchild.
rlg 😉
hi MGR,
what's the name store u bought that part in raon 2sc5200/2sa1943, how much per pc.
rlg 😉 😉 😉
what's the name store u bought that part in raon 2sc5200/2sa1943, how much per pc.
rlg 😉 😉 😉
hienrich said:
Hi hienrich,
No, I'll bring a capacitance tester. Some DMMs have this function, but I haven't tried if these are 'capable'. The requirement essentially is that the meter must be able to see into the nF range, and that the test voltage used by the meter is low enough so as not to bias the B-E junction (so the test signal should be ~100mV).
Cheers!
Clem
hi clem_o,
I hope I aquire such tester soon, I hope I could find one in Cebu.
pls. post what ever will be your developments.
hi rlg_200
what
430 a pc.
Id rather go for 5200s and 1943s
well I still hope to find them here as originals...
I am so lucky to have some MJLs given to me as bday gift
from a cousin. but still not enough for some future projects.
maayong gabi i natong tanan,
macweb
I hope I aquire such tester soon, I hope I could find one in Cebu.
pls. post what ever will be your developments.
hi rlg_200
what
430 a pc. Id rather go for 5200s and 1943s
well I still hope to find them here as originals...
I am so lucky to have some MJLs given to me as bday gift
from a cousin. but still not enough for some future projects.
maayong gabi i natong tanan,
macweb
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