@GYRO:
I read that thread quite carefully - Zlymex used ffirst 2 (out of 7) listed sources and paid only 1.6 RMB (0.23 USD) - genuine parts (diamond logo)
I made a vague statement that sources on TaoBao charge 1.7 RMB (0.25USD) - the sources I am referring to were provided by Zlymex.
Zlymex used the first 2 sources and received parts with diamond logo (= 17th radio factory of shanghai).
I just wanted to point out that some locals are trying to sell parts at 0.75USD and pay themselves less than 0.25 USD - easy money.
I will source those parts locally in Shanghai - this way we will be sure to source the genuine parts from 17th radio factory.
Any thing wrong with that approach ... ?
Flinstone
address details:
17th Radio Factory of Shanghai:
No.175, Dongjiadu Road, Huangpu District, Shanghai, China +86 21 6377 2411
(My highlight)
Frankly, I don't think that's the case at all, or technix's intention. I am not surprised that the factory would charge a higher factory gate price to supply parts to a 'member of the public' and charge a handling fee for such low volumes. Many (most) chip manufacturers wouldn't be prepared to do business on this basis at all. A factory charging a higher price for a premium quality low noise reference zener variant is not unexpected. Other members have also purchased parts from Taobao / Aliexpress with diamond logos only to find that the delivered parts were just re-marks of inferior ones (as is common practice), the logo is no guarantee at all (which is why Zlymex had to sample test them before shipping!).
The parts that Zlymex
very kindly supplied were very low noise, so undoubtedly from the 17th Radio Factory, however their zero TC current was way in excess of the generic datasheet value for a 2DW233: around 20mA (from my and others' measurements) versus 5mA. They achieve low noise as 'advertised' but given that they came from Aliexpress in plastic bags at low cost could well mean that they had failed a non noise related parametric test. There's no way to tell one way or the other as there was no supply chain traceability. Iirc, the testing that technix has done indicates a the zero TC current of the factory x233 parts is around 5mA. If that proves not to be the case, then people might then have some reason to question.
To repeat, Zlymex was a perfect gentleman in sourcing parts which at the time were not easily available to the community (based on the information available to him from Chinese language forums) and achieved the expected low noise performance. He was not however in the right location to be able to visit the factory and negotiate parts directly.
At the end of the day, it is a matter of trust for individual members to choose whether to purchase in this thread or not. If they wish to question the selling price then they should probably go elsewhere. You should undoubtedly go and do whatever you wish to do without recourse to this thread.