Your shrillness at the top end could be either jittery hash from a DAC or it might be the metal drivers used on the F30. (All rigid metal drivers suffer from unwanted ringing and designers must all try to mitigate this within the crossover design - some people like this sound as it may sound more "etched" or detailed - others prefer paper/fabric damped cones as no crossover seems to completely cure the ringing problem)
Since you can usually get a Benchmark DAC1 for a home trial (from a pro music center), I'd recommend you try it and see and report back. If you don't find the DAC1 does enough for you then you can usually return it within 30 days - no questions.
Since you can usually get a Benchmark DAC1 for a home trial (from a pro music center), I'd recommend you try it and see and report back. If you don't find the DAC1 does enough for you then you can usually return it within 30 days - no questions.