Headphones

Sound Tuning
This player not only offers three different digital filters but also incorporates a KORG Nutube 6P1 in its analogue output by way of further 'sound tuning'. All the measurements in our Lab Report were undertaken with the SP2000T in its default 'op-amp' output mode but a total of seven options are offered in the menu including five 'hybrid' modes inbetween these 'op-amp' and 'tube' settings. And, yes, I tested them all... In practice there's no change in output level, output impedance or frequency response across all the seven output modes [the digital filters do impact response, stopband and time domain behaviour].

However there is an increase in distortion and slight decrease in A-wtd S/N ratio across the seven modes, with the op-amp output [black trace, inset Graph] combining the lowest 0.0002% (1kHz/0dBFs) distortion with the widest 112.7dB S/N. The 'Hybrid' modes 1-5 offer 0.004%/112.5dB, 0.006%/112.2dB, 0.0075%/112.2dB, 0.0085%/112.1dB and 0.01%/112.0dB [grey, green, purple, orange and cyan, respectively] with the final 'tube' mode [red] at 0.02%/111.8dB. As the inset Graph also illustrates, there is no difference in harmonic distortion between any of the modes with (digital) inputs below –25dBFs. PM