(http://www.bursonaudio.com/images/Picture%20019.jpg)
http://www.bursonaudio.com/Burson_HDAM_Module.htm (http://www.bursonaudio.com/Burson_HDAM_Module.htm)
you could goto opa627 or AD857 or Burson discrete opamp. My Burson is in the mail.
Supposedly the Burson has the most detail and presence over the top opamps. I will see.
I like the 227 a bit more than the 2604 but the change between the two in this application is not vast. I am hoping that the Burson opamp is. The 227 has verve than the 2604. Detail might be the same between the two.
The Burson is about $100.
(http://www.referenceaudiomods.com/images/products/audiocom/opampt2_s.jpg)
For half the price you might try a setup from Reference Audio Mods: http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=OPAMPS (http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=OPAMPS)