Dual Class-A II Headphone Amplifier CCIF Distortion 19/20 kHz 1:1 using the null test method at 750 mW into 30Ω.  19/20 kHz levels suppressed by approximately 50 dB. Sidebands at 18 and 21 kHz are at their actual level.
CCIF 19/20 kHz Distortion is approximately 0.002% at 3/4W output.

DCAO II CCIF Distortion

2016 Wayne Kirkwood