Hi, I'm interested in this as well. I have a DT 770 pro 250 and it's just enough for mixing, but I could use a bit more power (especially when mixing the direct input which effectively loses me some volume).
I bought a FiiO Olympus E10K on a whim without doing research, and though the volume is perfect it doesn't actually has any line in option so I can't put it between my SSL2 and my headset.
Any recomendation for an amp in the same ballpark (around 100e). I found this which has a coaxial in, not sure how I can go 6.35 to coaxial in though?