The DAC is the 20 bit precision AD5791 which provides an output span across the +/- Vref inputs (power supply being greater than Vref). However, I want an output almost 3x that span. I can do this by putting an opamp on the DAC o/p, or I can feed the precision +/-5V reference voltages I am using through a couple of opamps.
Naturally, I am trying to keep the noise as low as possible. Which is the best approach?