check out this transistor

Wagener · 16th May 2004, 12:13 PM

I got it for a third of the price of a ON or Toshiba. It is a MJ15003. The ON I measured has a hfe of 39, the one in the photo has a hfe of 18.

According to specs the HFE should be between 25 and 100.

Does anyone recognise this brand of transistor?

When using this in the output stage of the leach amplifier where should the hfe be more or less? I don't suppose 18 will do the job?

Cradle22 · 16th May 2004, 12:23 PM

Hi!

I certainly use them a lot, inside of ESP's P3A, P68, DoZ...
I never had a problem with them.

In Germany those MJs are being sold by Reichelt, a lot cheaper than original ON MJ15003 / MJ 15004

But I did not measure them, or know what brand it is. Maybe an email to Reichelt could sort this out...

Bye,

Arndt

Zombie · 16th May 2004, 12:24 PM

Hmm...a transistor in bondage

http://sound.westhost.com/counterfeit.htm

Cradle22 · 16th May 2004, 07:22 PM

No, these are not counterfeit.

At least I would judge so by them being

a) sold at Reichelt in Germany

b) Working stable for at least half an hour with full power P3A (42 V rails) with 2 ohms of load at high volume... Just for curiosity I substituted them for 3055s in the P3A, they blew up under the same conditions after about one minute of playing...

So, original Motorola / ON? No...
But counterfeit? No...

Bye,

Arndt

destroyer X · 16th May 2004, 08:05 PM

Maybe is your case, maybe not... take a look overthere.

You will see photos....and this may be helpfull to have a conclusion.

Carlos

djk · 16th May 2004, 10:20 PM

"b) Working stable for at least half an hour with full power P3A (42 V rails) with 2 ohms of load at high volume... Just for curiosity I substituted them for 3055s in the P3A, they blew up under the same conditions after about one minute of playing..."

Considering that a 2N3055 is only rated at Vceo(sus)60V, I'm surprised it didn't blow up as soon as you ran 84V (±42V) to it.

A 3055 will handle 100V only when the base is reverse biased, and that is not an audio amplifier.

B.I.G · 16th May 2004, 11:51 PM

I have opened one and it has a Full SIZE DIE !

They are good but i can only find MJ15003 and not 15004

16th May 2004, 12:23 PM	#2
Cradle22 diyAudio Member Join Date: Jan 2003 Location: Dortmund, Germany	Hi! I certainly use them a lot, inside of ESP's P3A, P68, DoZ... I never had a problem with them. In Germany those MJs are being sold by Reichelt, a lot cheaper than original ON MJ15003 / MJ 15004 But I did not measure them, or know what brand it is. Maybe an email to Reichelt could sort this out... Bye, Arndt __________________ ************************ A Sacrifice For Freedom

16th May 2004, 07:22 PM	#4
Cradle22 diyAudio Member Join Date: Jan 2003 Location: Dortmund, Germany	No, these are not counterfeit. At least I would judge so by them being a) sold at Reichelt in Germany b) Working stable for at least half an hour with full power P3A (42 V rails) with 2 ohms of load at high volume... Just for curiosity I substituted them for 3055s in the P3A, they blew up under the same conditions after about one minute of playing... So, original Motorola / ON? No... But counterfeit? No... Bye, Arndt __________________ ************************ A Sacrifice For Freedom

16th May 2004, 08:05 PM	#5
destroyer X diyAudio Member Join Date: Feb 2004 Location: Recife - Brasil Northeast	Read Rodd Elliot Counterfeit transistors Maybe is your case, maybe not... take a look overthere. You will see photos....and this may be helpfull to have a conclusion. Carlos __________________ Try to build an amplifier folks ... it is pure adrenaline!

16th May 2004, 11:51 PM	#7
B.I.G diyAudio Member Join Date: Mar 2004 Location: Home	I have opened one and it has a Full SIZE DIE ! They are good but i can only find MJ15003 and not 15004 __________________ B.I.G

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16th May 2004, 12:24 PM	#3
Zombie diyAudio Member Join Date: Feb 2003 Location: At home	Hmm...a transistor in bondage http://sound.westhost.com/counterfeit.htm

16th May 2004, 10:20 PM	#6
djk diyAudio Member Join Date: Feb 2001 Location: USA	"b) Working stable for at least half an hour with full power P3A (42 V rails) with 2 ohms of load at high volume... Just for curiosity I substituted them for 3055s in the P3A, they blew up under the same conditions after about one minute of playing..." Considering that a 2N3055 is only rated at Vceo(sus)60V, I'm surprised it didn't blow up as soon as you ran 84V (±42V) to it. A 3055 will handle 100V only when the base is reverse biased, and that is not an audio amplifier.

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