Sonic Imagery seems to offer for this opamp a DIY kit.
Once again, a caution in regards to jumping to conclusions with the DEXA and Burson discrete Opamps for the EE Minimax DAC Plus; if you only have one rig and never want to change out anything again, sure you can claim whichever is "best". I have built multiple rigs since the article and have consistently found no predictable result in which combination or set of DEXA and Burson Opamps will be superior.
Case in point, I just put in new speakers two days ago and clearly with these speakers and components the Burson are more to my liking, although in the system just prior the NewClassD Opamps were my choice.
It's just not as simple as this or that is better. Thus I recommended the two sets so as to have a system-change-proof solution.