I have a Benchmark DAC1-Pre that I am using with 2 Krell FPB350 MCX monoblocks. The combination works fine at the regular DAC preamp output setting which uses a factory 20dB pad setting. The idea is to achieve normal listening levels with a volume control set above the 11 o'clock position. If you need more juice, there is a 10 dB and 0 dB pad settings.
Hope this helps
Hope this helps