The "Freebird" ultra clean ultra simple preamp design

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I'll be... There must be higher powers at work here. I tried opa627 and buzz, opa604 and buzz. In the back of my mind I seem to remember reading something about buzzing and if you couldn't get a preamp or similar stable then you should try opa134. And what do you know? No Buzz! Dead quiet.
 
Hi Russ

I am very much interested in freebird. But one thing I can not understand I have seen the DataSheets of OPA627 and OPA228. The PIN configurations of these two OPamps look different I think but you said that you have OPA228 with the same PCB . Can you explain that to me.
I am new and plz do not mind my stupid questions :)

I am also attaching its image
 

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Dear Wasim:
when working with an Op-Amp one needs to be more concerned with Invereted and non-inverted inputs and outputs along power supply pins, in pinout picture that you attached it is clearly evident that OPA627/228 share the same pinouts for inverted and non-inverted inputs both at pin 2 and 3, outputs at pin 6, postive power supply at pin 7 and a negative rail at pin 4, as for offset trim pins, not many preamps use offset pins.
rehan
 
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