Sennheiser HD600 work with Creek OBH-11?

I have a pair of Sennheiser HD600 headphones, and want to get an inexpensive headphone amplifier to use with them. I have a very limited budget right now, and was considering the purchase of a used Creek OBH-11 headphone amp. I note that the OBH-11 has a power rating of 350 mW into 30 ohms. The Sennheiser HD600's have an input impedance of 300 ohms, so I am concerned that the OBH-11 might not be a good choice to drive the HD600's. Does anyone have experience with this combo, and if so, what are the pros and cons?
Have the set-up mentioned and my 600's are easily powered by the OBH-11 - usually set no higher than 12:00. A very nice sound for a reasonable cost. You'll not need add'l juice as the unit can provide power to even painful listening levels (discovered by mistake).