Would the real 2SA1492 please stand up!!!

[Zero Cool]

I am repairing a power amp that uses 2SA1492 transistors. the previous repair that did not last had 2 different date codes on the 2SA1492 transistors. but both at least look similar. the set i just ordered from audiolab.com arrived and look totally different. the date code system is nothing like the other two. the devices that were in there had date codes of 89 O and 23 P however the devices that arrived from audio lab have date codes of 4F. they are the devices on the far left. even the text looks different. the physical bodies look the same and the back plates look the same..... I am afraid to fire this thing up at this point....


Zc

[tinitus]

found this pic

[Zero Cool]

Yup see those i think are real and the 4P is the fake. but they survived power up and a few full power pulls in the amp. I will run it at 1/3 power and see how it does thermally. but whatever they are they are working.... but i am skeptical to buy parts from audiolab again....


Zc

[Zero Cool]

well i spoke too soon. they blew up. Audio lab is being kind and sending a refund. But be advised. when I asked about there counterfeit policy. I got this reply:

"in many cases that's what we get when we order these parts from Asia. Since the original Sankens are few and far between due to being discontinued for years, it's a guessing game as to what any given vendor will supply."

it looks like the counterpart is correct just the 1492's are fake....

[Zero Cool]

I smashed open the fake 1492's and they have a tiny 2-3mm square die compared to the 10+ mm sized die in the real 1492's!

I smashed open the counter parts that are now blown and they look to be real.