How do I enable the op-amp on motherboards with integrated amps?

[BetaWolf]

Just upgraded some components on my motherboard. It has an isolated, shielded sound circuit with a Realtek ALC1150 codec and Texas Instruments OPA1652 op-amp.
 
The manufacturer's page advertises it as being able to drive 600 Ohm, studio grade headphones. I have my AKG K702 connected to the motherboard's line out, and the audio I'm getting is definitely not amped. It can just barely drive my cans. The separation is horrible, the soundstage is narrow, and the levels themselves are quite low at max volume.
 
The name of the motherboard is the MSI Z87 Mpower Max. I see no way of enabling the amp through software, nor are there jumper switches anywhere on the audio circuitry. It isn't documented in the manual, nor on MSI's website, nor does a Google search return anything. What do I do here?

 

[PurpleAngel]

Have you tried updating to the latest Realtek audio software?
http://us.msi.com/product/mb/Z87-MPOWER-MAX.html#download

 

[BetaWolf]

Downloaded that the day after I installed my motherboard, less than two weeks ago.

 

[ClieOS]

The opamp is part of the audio circuit so there shouldn't need to enable (*it should be working all the time). Not to sound silly, but have you checked the connection (might not plugged in the whole way)? You might also want to look into the Windows volume meter and make sure the setting are not configured to 7.1ch as default.

 

[milosingh]

What is your point of reference? Have you tried other sound cards?

 

[jiiteepee]

If opamp is selectable feature then, maybe setting Headphones as output target is the way to go.
Another possibility is that the opamp is intend for Headphone output found in case front panel.