My Transistors, original or copy?

[anatech]

Hi Pete,
Thank you so much for the index ! It's also good to know my data books are accurate.

Those transistors look to be very good for a SymAsym.

As for defective or substandard merchandise, it comes down to human nature. Greed often over rules common sense.

-Chris

[PB2]

Originally posted by anatech
Hi Pete,
Thank you so much for the index ! It's also good to know my data books are accurate.

Those transistors look to be very good for a SymAsym.

As for defective or substandard merchandise, it comes down to human nature. Greed often over rules common sense.

-Chris

Hi Chris, and thank you for the interesting thread. It is challenging detective work to identify these fakes as irritating as it is that they exist in the first place.

I've looked at SymAsym a few times but not recently.

I think that these are good devices for many designs, but stability would have to be considered because they're so fast as I'm sure you know.

Yes it is greed, but I'm amazed at how much effort is put into making fake parts, and the quantity that are being produced.

Pete B.

[anatech]

Hi Pete,
I am currently (very slowly) playing with a couple SymAsym boards. They sound really good, and are overkill for what I wanted and expected. So overkill it is!

We must thank Mike and Pavel who developed this amp, and Carlos who started the first thread. If you get a chance you should zap a couple together.

-Chris

[PB2]

Originally posted by anatech
Hi Pete,
I am currently (very slowly) playing with a couple SymAsym boards. They sound really good, and are overkill for what I wanted and expected. So overkill it is!

We must thank Mike and Pavel who developed this amp, and Carlos who started the first thread. If you get a chance you should zap a couple together.

-Chris

Hi Chris,

Thanks for the suggestion on the SymASym, but I just don't have the time lately. I am very tempted to do my own design, but again I just don't have the time. Maybe a project with one of my sons if they show some interest. We'll see.

I'll try to post some pictures of the parts when I get a chance, then pop a few open.

All the best to everyone for the New Year!
Pete B.

[anatech]

Hi Pete,
Once you do post those, I'll clean out our exchange here to keep the thread clean.

-Chris

(Try the SymAsym out. Inexpensive project that matches your parts)

[PB2]

Hi Chris,

I cut open the case on four of these using a cutoff disk in a Dremel tool. They did not open exactly the same way as the ones seen at Elliott's site, but they look good. The die is about 4mm on a side which makes sense since they're lower power being 100W. Elliott was looking at higher power parts with a size of 5mm on a side, the fakes were typically 3mm.
The font looks exactly like this known good part shown at Elliott's site:

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

As I said before the font is heavy and the date code is centered.
You asked about quantity, this total lot of Sanken parts totalled
over 100,000 parts, close to 200,000. The highest power transistors are 125W, and the lot included other parts such as diodes and voltage regulators. I won't list the numbers here since people seem touchy about this sort of thing.
I'll try to get some pictures soon.

Pete B.

[anatech]

Hi Pete,
I'd say those are real.

Was the dremel fun? You must have had a foul smelling dust storm there. I hope you were wearing a mask!

-Chris

[Eva]

The way in which that die is attached to the copper tab seems quite strange to me. Genuine devices shouldn't have any kind of substance around the die, either white or transparent. Also, genuine devices shouldn't have lots of solder around the die as if it was soldered by hand there. I know that this picture is not yours and is taken from Elliot's site, where he believes it to show a genuine device, but I'm in doubt.

[PB2]

Originally posted by anatech
Hi Pete,
I'd say those are real.

Was the dremel fun? You must have had a foul smelling dust storm there. I hope you were wearing a mask!

-Chris

Hi Chris, Well, it would have been fun if I had nothing better to do, however, I can think of many better things to do, LOL!
I'm doing this out of curiousity, and because I might use some
of these parts for my own projects.

Yes, mask and goggles, smelled like burnt transistors!
Anyone know what the case is made out of?

Pete B.

[PB2]

Originally posted by Eva
The way in which that die is attached to the copper tab seems quite strange to me. Genuine devices shouldn't have any kind of substance around the die, either white or transparent. Also, genuine devices shouldn't have lots of solder around the die as if it was soldered by hand there. I know that this picture is not yours and is taken from Elliot's site, where he believes it to show a genuine device, but I'm in doubt.

I wondered about that also, Eva, since they said the fakes had something like silicone sealer over the
top of the die. I don't think that's solder in that picture, looks to me like some kind of goop, but I'm not
sure you could be right.
I believe that die coatings have been used, over DRAMs for example as a sheild against alpha particle
radiation which causes an increase in MTBF of soft memory errors. The plastic package was molded
right over the die in the parts I opened. I'm not sure how these Sanken plastic parts are fabricated.

Pete B.