Broke my own rule about ebay and Asian parts.

[nigelwright7557]

I fell foul of ebay fake parts a few years back.
Transistors blowing up even when lightly loaded.

In my wisdom I decided to buy some B9A pcb valve bases from AliExpress.
Got one soldered in a fully populated board.
When I tried to put the valve in it was very tight.
The valve pins just bent.

Totally useless so binned the lot.

So its reputable dealers from now on even if they are more expensive.

 

[adrianbaugh]

Same here. I tried to buy a couple of IXYS IXCP10M-45s from eBay for a Tubelab SSE build a few years ago. I tried a couple of sellers but none of them worked. Initially I thought I was mishandling them but eventually it became clear they were fakes (dodgy labelling etc.) I got the parts from Mouser in the end and they worked fine. Lesson learned: use reputable dealers. My list at the moment is: CPC / Farnell, RS Components, Mouser, TME.

 

[kodabmx]

Funny, that. I buy tube sockets all the time through eBay and they have been fine. Chassis mount, mind you, but fine.


I would try these: 9pin B9A plastic tube socket for EL84 12AU7 5670 6922 ECC83 6DJ8 PCB mount x10 | eBay


If they aren't perfect, open a case and get a refund.


These are fine sockets: 9 Pin Vacuum Tube Sockets For 12AX7 6DJ8 5670 EL84 ECC83 Bottom Chassis Mountx10 | eBay
The Soviet ones are even better.
And the only semiconductor parts I'll buy through eBay are things like LM317 or UF5408... I found for TL783 etc they are almost cheaper from Digikey and you get them the next day.



Still though, getting 100 UF5408 for 3 cents each and no issues at all? How can you complain?

 

[nigelwright7557]

Still though, getting 100 UF5408 for 3 cents each and no issues at all? How can you complain?

The trouble it is just luck of the draw whether you get good or bad parts.
I have been unlucky and had bad parts.

So I don't take the risk now and just buy from local genuine suppliers.

 

[wg_ski]

Still though, getting 100 UF5408 for 3 cents each and no issues at all? How can you complain?

Have you actually checked recovery time on them? How do you know you didn't just get sold some generic 1N540x? Or does it matter?

I did buy a 3000 pc ammo box of generic 1 amp rectifiers for some ridiculously low price from BG Micro. As long as they conduct in one direction, take 25 volts at an amp or so, and have a tempco of about 2mv per C, I don't really care otherwise. It saves me from having to use up ultrafast and high voltage diodes where they may not be needed. Same for the 2SC1815's I got at the same time - for use where I want an ECB based generic. The only place where a fake might have been an issue were the triacs - they behaved normally at a 2 to 3 amp load so I'm satisfied, whether they meet spec or not.

 

[miklos]

Since everything or almost everything is made in China, it wasn't difficult to brake your own rules.

 

[basreflex]

I bought ADAU1701's at 4 euro's/pc at aliexpress )(free shipping at 5 pcs/20 euros), while at digikey 9 euros. free shipping at 50 euros. just have to wait longer for alieX parts..
I stay away from silicon with less than 40 pins, all the low pincount parts with generic application are too easy to fake. (bipolar, fet etc)

 

[kodabmx]

Have you actually checked recovery time on them? How do you know you didn't just get sold some generic 1N540x? Or does it matter?

I use them to rectify 75kHz. A 1N5408 burns out in 2-3 minutes.

 

[wg_ski]

Ther is a huge cult of users out there who are convinced they need FR rectifiers in the 60 hz transformer supplies for their LM3886 chip amps. They might never know the difference. An SMPS builder finds out very quickly. And in other applications, a 540x might not outright burn up, but not behave properly either. Then it would be hard to tell if the rectifier were to blame without measurements (at least in circuit waveforms).