Measurements
Please note that all measurements are made with USB input of the DACs. Two posts down there is a comparison of Toslink to USB.
I always like to match levels of DACs where possible to make a fair comparison. Alas, even though Benchmark documents that the unit by default outputs 24 dBu (12 volts RMS), it puts out copious more output than that. I had to use a "pad jumper" inside the unit to dial in -10 dB of attenuation to match that of RME ADI-2 which indeed maxes out at 24 dBu. In this dashboard view of DAC3, I have one channel with default output and the other with -10 dB:
As you see, the non-attenuated channel outputs nearly 20 volts RMS, corresponding to whopping +-28 volts or peak to peek!
With that kind of output swing if you are bored, you can hook up the DAC3 to drive your Christmas tree lights!
Dallasjustice uses the much higher output to good results in room equalization. The most effective way to deal with troughs in room response is to simply bring down the levels of all the other frequencies. This gives you a flat response but now you have much less gain to drive your speakers. Having so much headroom and output capacity in the DAC3 helps mitigate this.
For the rest of these tests, I ran with the attenuation at -10 dB to match the RME as mentioned. Note that performance without this attenuation is different (sometimes better, sometimes worse). Such is life when we try to make apples vs apples comparison.