Coustic DR (Design Reference) missing op-amp

[amc32]

I bought this amp today I was told it worked. I knew it didnt when I saw one gain controll missing.After futher internal inspection,I notice someone removed it's one and only op-amp in the pre-amp section.And replaced it with an empty socket.I need help finding a replacement.
OEM or Replacement .

 

[amc32]

Forgot to post model of amp,it is: AMP 505DR 2x50watts RMS @ 4ohm

 

[Perry Babin]

The empty socket is OEM and was empty on all of the DR series that I've seen (all were working).

 

[ppia600]

Even the one on ampguts is missing

http://ampguts.realmofexcursion.com/Coustic_505-DR/inside1.jpg

 

[1moreamp]

It could be a simple crossover header using a simple parts carrier to hold the components...just thinking out loud🙂 🙂 🙂