Not so Genuine OPA2134

Hi

Yesterday I had a "ear opening" experience.

I have been using opa2134 and buf634 in my diy headphone amp now for over a year and was pretty happy with the results. Out of the blue I had a desire to swap out the current pair of opa2134 that I was using in the amp(bought from lamington road) with the ones I bought from rs components.
Lo and behold in no more than 30 seconds I realized that I had been sold fakes by the lamington road guy :-). Mind you the old ones didn't sound bad at all, its just that the new ones sounded better. On closer inspection with heavy lighting and a large magnifying glass I could make out the subtle differences in the print font. I don't really know what I was using earlier but the new ones have more dynamics, smoother on the top. I wonder if I was using re-labelled TL072 or something similar ?
Now here is the best part, I bought the op amps from lamington road for 300 a piece and from rs around 200 a piece. All this while I thought since I got the opamps from lamington road at a higher price, its a good chance they are authentic, and since they are cheap who would want to counterfeit them ? Wasn't economically viable. I was dead wrong. Both the opamps read BB OPA2134AP.

Assuming that both sets are genuine, would there be so much of a difference in the manufacturing process to make em sound so different ? I doubt that but I wonder.
Now someone would ask how am I so sure the new ones are authentic ? :-) well I don't know. They sound better so they must be :-)

Manek

Ps : anyone know what's with rs components india ? Most of the stuff reads "out of stock". I wanted to purchase a couple of opa2107's but not available. Any other good reliable(brick and mortar) source in mumbai or any other city ? I dare not go to the lam road guy I used to for this one, these opa2107 are expensive :-)

Manek