The Cmoy in the Altoids can from JDS Labs.
There was some discussion elsewhere in the Forums about some headphones needing voltage and some needing current, and that dynamics needed one and planars need the other. I am oversimplifying the electronics - and I have no idea whether it is correct - but that was the conclusion.
From my own experience, it might be the case that the Cmoy design works for dynamics and not for planars for that reason being discussed. The Cmoy design is amazing in how with a very few tiny parts, it can create a very nice sounding portable amplifier. So, it seems likely that it has some significant tradeoffs, and those might be the same thing that is needed to work with planars.
But the above is just speculation.
what was the sound like when you hook it up to the Mad Dog?
I done 3-4 hours of researching last night, seems like Mad Dog need a lot of mW to drive them. When I first look at headphones, I thought impedance was the important thing but apparently there is more to the equation than impedance to make a headphone sound good.