I purchased the M-Stage from the Head-Fi forums in 2015. Works perfectly and sounds great! The unit came with the Burr Brown OPA 627 op amp upgrade from Tam Audio. I had since upgraded to a Burson Supreme Sound V5 dual op amp, this upgrade was an huge improvement in the sound of the amp. Both op amps are included with the M-Stage.
Buyer pays shipping and any associated fees. Please feel free to contact me with any questions.