A question on emitter follower use
A BJT has current gain - this might be 100 for instance. 10V across 1 ohm implies a current of 10 A and this would require (approximately) 10A/100 into the base. That's a current of 100mA to be sourced by the DAC and clearly the DAC isn't geared-up for that. This fact stops a BJT being a true voltage follower i.e. there are limits to how far things can be pushed.

Try using an op-amp and BJT (or MOSFET) configured as a voltage follower: -



You get the added benefit that the 0.7V base-emitter voltage error is "fixed" by the op-amp due to the action of negative feedback. The op-amp also keeps the output voltage stabler under a wider set of load conditions again, die to negative feedback. If you need 10A on the output then look for a power op-amp that can deliver up to an amp to the BJT base because, under worst case conditions, the current gain of a BJT can fall to as low as maybe 10. 

Just so the BJT police are happy, I'm aware that current gain is strictly speaking collector/base rather than emitter/base current but it makes little difference to this answer.