Warmth
From Benchmark
John Siau's post about adding "warmth" to the signal chain
Quoted from Head-Fi post byt John Siau:
We designed the DAC1 for maximum transparency. If you want to add warmth, you can't add it with a DAC1. Personally, I do not like what warm sounding equipment does to the sound of a piano. Warmth is wonderful on vocals, guitars and certain instruments, but it beats against the streched overtones of a piano. The overtones in a piano occur at slightly higher than harmonic ratios, and these create beat notes with the exact integer ratios produced by electronic equipment (and speakers). Too much harmonic distortion will make a piano sound out of tune.
Put on a pair of HD600 headpones, plug them in to the DAC1 headphone amp, and listen to a solo piano recording. This combination will deliver far lower distortion than any speaker/amplifier combination. The 0-Ohm headphone drive on the DAC1 is extremely clean under load.
