[NelsonVandal]

Do you think the cheapish AD797's and OPA627's are fakes, or just bought in large batches and so can be sold cheaper? They're delivered from Hong Kong.

 

[slowpogo]

I just bought two OPA637's from that guy for $30 shipped.

I remember several months ago there was a legit site selling OPA627's for cheap, that I found out about here, and nobody ever posted complaints. So I just assumed that sometimes, some circumstances would allow them to be sold cheap.

The seller has an excellent feedback record (99.4% I believe).

I hope they're real. I've never heard the 637 before, so how would I know if they're fake?

 

[ericj]

Sometimes you run into people who are selling engineering samples. Which is pretty unethical IMHO. But I'm pretty sure that you can't get samples of the 637.

Fake semiconductors exist, but, I don't know how to tell you to recognize them. Unless the printing on the package is of extremely poor quality - like they painted it black and then printed it again. Even if two parts don't look exactly the same, they could have just come off of different production lines.

 

[FallenAngel]

I think they stopped OPA637 samples recently, but they had them for a while, and a few years ago, they even had OPA627 samples.

Why do you think so many are sold on eBay in quantities of 5?

 

[ericj]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif I think they stopped OPA637 samples recently, but they had them for a while, and a few years ago, they even had OPA627 samples. Why do you think so many are sold on eBay in quantities of 5?

Yeah, and these guys screw up the sampling system for the rest of us.

Some companies may be of the opinion that they don't want to sample to anyone who's not actively designing a product that will potentially lead to larger sales, but many companies are just happy to have the word out about their products and figure that hobby use at the very worst doesn't hurt them in the long run.

Way back in the day, Fairchild Semiconductor refused to give samples to some hippie in california by the name of Wozniak. To this day, Apple has never purchased a single Fairchild part.

 

[user18]

For a while, there was an ebay listing for OPA637 for $5 each, but it was 50pcs. I would have bought them and offer it for the same price here, but they didn't have any OPA627 to go with them. The only ones I saw were $20 each.

 

[AudioCats]

kimsfashion was selling OPA637 for $22/pair for a while on ebay, I got four from him, they do sound better than AD843 for classical and vocal, so I guess they must be the real stuff.

 

[Tsuioku]

There seems to be a person selling out of China for pretty cheap claiming that they are used.  ie 2x AD797BR for $8.50
http://cgi.ebay.com/2PCS-AD797BR-Mono-Op-amp-Ultralow-Noise-/350410104095?pt=LH_DefaultDomain_0&hash=item519611dd1f
 
Their rating is quite high (> 1000 feedback @ 99.7% positive) but the pictures of the IC look different from what I am used to seeing.
New Markings or fake?