Problem with op amp tweak. Pls help!

I sent my cd player to a friend's house two days ago. He mod the TLO71 with the OPA627 today.

A socket was used so that I can try different op amp later.

He also re-soldered the wire at the RCA joints as it seems like not properly joint.

The player spin. All is well BUT:

According to him, there is a high pitch sound at quiet passage. He put back the TLO71 but the pitch is still there. I have not heard from the player after the mod and I do not know how bad it is. What could be wrong?
 
Be cool now

Maybe your friend has some problems with RF- interference. Have you asked him if the CD had this trouble BEFORE he made the changes? Let's hope that is the case!

Let me also point out, it's also possible that the pcb layout MAY not be as good as it takes togheter with the OPA627. This amp is a high speed device and need much more serious decoupling than the rather slow TL071.