5PCS OPA2134 OPA2134PA High Performance Audio Operational s DIP8 DIP-8 DIP 8 8DIP IC Chip

I was excited when these arrived. Upon inspection, very opamp has a 'BB' logo on it. For those that know, Burr Brown opamps are very high quality. Some, like Juried Engineering, get away with charging insane prices for a single amp, like up to $20+ (i've seen some for $40ish on here too) These are $10 for 5 units, so not bad at $2 an amp... However, it makes me very suspicious of their origin and authenticity. My plan is to, sometime in the near future, grab a known genuine Burr Brown amp and do a side by side bench test of both units. Who knows? They may be just as good, but at 1/10th the price I have my doubts. Until then, I'm the owner of 5 suspect amps that took too long to get here.