solderdude
Grand Contributor
Objective performance shows severe problems. However it also points to lots of power availability and potential for modification of frequency response of the headphone. As it turns out, these factors work in favor of Sennheiser HD-650 producing beautiful tonality and music.
Subjective Headphone Amplifier Listening Test
I started testing with the Sennheiser HD-650 and the result was unexpected: almost infinite amount of power with warmer/nicer amount of bass. I switched to my standard amp, the RME ADI-2 DAC and it simply could not keep up with the Crack either in amount of power or bass.
This is exactly what Marv's (SBAF) beef is with 'measurements extremists', and it seems in particular with Amir .
Obvious amounts of distortion reaching over 1% (bottom of the SINAD chart), having channel imbalance and an output resistance of about 1/2 (breaking the 1/8th rule even with a headphone showing impedance swings) doesn't lead to 'poor sound quality' but rather can give a pleasant and impressive change to certain headphones.