According to the Phonitor X User's Manual (
https://spl.info/fileadmin/user_upload/produkte-w/Phonitor_x/Phonitor_x_BA_EN.pdf), the balanced headphone output actually has worse noise and dynamic range specification compares to the single-ended headphone output:
Balanced headphone output:
Neutrik 4-pin XLR connector
Pin wiring: 1 = L (+), 2 = L (-), 3 = R (+), 4 = R (-)
Impedance: 0.36 ohms
Damping factor: 180 @ 40 ohms
Frequency range: 10 Hz to 300 kHz ( -3 dB)
Crosstalk at 1 kHz: -90 dB
THD & N: 0.00091 % (at 0 dBu, 1 kHz, 100 kohms load)
Noise (A-weighted): -98 dBu
Dynamic range: 130.5 dB
Single-ended headphone output:
6.35 mm TRS connector
Pin wiring: Tip = Left, ring = right, sleeve = GND
Impedance: 0.18 ohm
Attenuation factor: 180 @ 40 ohms
Frequency range: 10 Hz to 300 kHz ( -3 dB)
Crosstalk at 1 kHz: -90 dB
THD & N: 0.00091% (at 0 dBu, 1 kHz, 100 kohms load)
Noise (A-weighted): -103 dB
Dynamic range: 135.5 dB
The Phonitor 2 only has a 2 channel Alps volume pot, I wonder if it is actually a "dual mono" design rather than full differential balanced output. Not sure if the Phonitor X having 2 channel or 4 channel volume pot.
I am seriously considering the Phonitor 2/X recently for a "studio/dry sounding amp", then I found some treak with my Metrum Aurix and decided sticking with it.