eBay parts suck

[miniman82]

Don’t order parts on eBay, I’m convinced they’re all counterfeit. You can see the dies on these supposedly genuine transistors aren’t even 1/4th the size of the originals, and though the amplifier seemed to work OK they blew and torched a receiver I repaired at only modest volume levels. So learn from my mistakes, even if you don’t think it matters, it really does- even at low power levels.

 

[Mark Tillotson]

Yes, this isn't news though, it was getting bad ten years ago, nowadays you'd never buy any semiconductors from unknown suppliers if you want real parts.

 

[tomchr]

In other news: The bear still defecates in the woods. 🙂

B+D Enterprises is my go-to for obscure/obsolete parts. Anything in current production I buy through Mouser/Digikey/Newark/Future/etc.

Tom

 

[Bigun]

In other news: The bear still defecates in the woods.

LOL

Mostly you gotta avoid China, 99% of the fakes originated there, and if you are careful you can avoid the folk outside China who are re-selling the junk they got from China in the first place.

When you account for your time, and you only live once, just buy from a reputable source. If you can’t afford to do that, scrounge it from old e-waste or choose a different design - there are many roads to good sound (don’t get lost in the hype).

 

[indianajo]

I've gotten good transformers from ebay. Good power supplies from known companies. Good actuators. Companies too obscure for ***** to notice. Didn't order any semiconsuctors.

 

[nigelwright7557]

I bought some irfp240/9240 from China.
The amp powered up fine.
So job finished I unplugged my soldering iron and the glitch down the mains blew the amp up.
So I decided to buy next batch from RS to see how long they lasted.
Been going a year now.
Clearly fake parts had very low breakdown voltage.

The only thing I now buy from China (knowingly) is pcb's.

 

[wg_ski]

You didn’t actually expect to find real D424/B554 parts ANYWHERE, did you? The last ones I got were from MCM in 1988, when it was a very small outfit and sold just about any jap transistors that you could get. Use MJ21194 and 21193 and call it good.

 

[weissi]

Well, with semiconductors it's a difficult story... I'd say 50% of all semicons I've got where at least remarked. But otoh, I got parts I'd never would've got anywhere else in the world... As an example: Digital-Oversampling Filter: SM5814 - 5pcs for €25... I'd say it's a dice game.

 

[nigelwright7557]

Its a dice game.....

Bought some A2D's, AD876 and AD9220 from China as they were about 1/4 of price elsewhere.

AD876's worked great.
AD9220 output was too noisy and unusable.

 

[kn0ppers]

This comes to mind.

 

[Bigun]

the way I see it, there are more interesting things I can build than my lifespan will allow so why give myself any grief from dodgy parts

Sure, some old classic electronics can be kept going a little longer if you can find the real thing, but, everything has it’s day and at some point you either move on to a different solution or else roll up your sleeves and design a patch using modern materials that you know are good

Really, it’s just is not worth your limited time and energy - too many alternatives for your enjoyment if you can avoid getting stuck on the one solution because of some influencers who have only their own interests at heart...

 

[poynton]

Whenever I buy from China, I always make a test purchase first.

These are then cut open to check the die size.

All the photos are of " 2N3773s."

2 were bought from China and one from the UK.

I'll leave it for you to decide which is which.

Andy

.

 

[nigelwright7557]

And with the downsizing will likely come the breakdown voltage too.

 

[astouffer]

Someone told me about a large medical company that used the TO-3 7805 style regulator. Well the bean counters didn't like what that part cost from legit suppliers so they went on eBay and found them much cheaper. Well you can probably guess the fake parts had the same size die as the TO-220 style.

 

[davidsrsb]

Some brands the die was the same. The package made all the difference in behaviour

 

[wg_ski]

They did use different size die in the 7805 and 78M05 both in TO-220. The latter was only rated half an amp. The TO-3 and the ones without the M used the same die. Then there was an even smaller L die for the TO-92. The 3 die sizes had specific current limiting for the size. God only knows what may be in a truly fake die - or if it even had current/thermal limiting at all.

 

[poynton]

I thought that I would post an image of the latest batch of "2N3773"s to arrive.

I cut one open immediately to see what's inside.

I am not convinced the die is large enough but it is larger than some I've seen. ( see earlier post )

Andy

 

[jan.didden]

I get a lot of great deals through eBay. Don't blame eBay, they are just the store! Blame the seller, and maybe blame yourself for trying to get absolute bottom price.

You get what you pay for.

Jan

 

[nigelwright7557]

You get what you pay for.

I wont name and shame but on ebay but there is a semiconductor seller that charges full whack for fakes. I bought some iRFB4227's off him and they didnt last 5 minutes. Got some genuine ones and they worked great.

The only way to be certain with fakes is to buy from reputable vendors like RS, Farnell, Digikey, Mouser etc.

 

[wg_ski]

I thought that I would post an image of the latest batch of "2N3773"s to arrive.

I cut one open immediately to see what's inside.

I am not convinced the die is large enough but it is larger than some I've seen. ( see earlier post )

Andy

Yours is absolutely real. That is exactly what they are supposed to look like. Compare to 8013 date code aluminum cased 2N3773.