Technics DVD-A10 DVD-Audio player Measurements part 2
Fig.4 Technics DVD-A10, left-channel departure from linearity, 16-bit data (2dB/vertical div.).
Fig.5 Technics DVD-A10, waveform of undithered 1kHz sinewave at -90.31dBFS, 16-bit data.
Fig.6 shows an FFT-derived spectrum of the player's output while decoding CD data representing a 61Hz tone at 0dBFs. The noise floor is very low in level, while the only harmonic component that can be seen is the third, at 183Hz. At -96dB (0.005%), this is inconsequential. Dropping the load impedance to a punishing 600 ohms didn't raise the third harmonic, but some higher-order odd harmonics now made an appearance at the -100dB level. Again, this will have no subjective consequences, and implies that the Technics DVD-A10 has a beefy output stage.
Fig.6 Technics DVD-A10, spectrum of 61Hz sinewave, DC-1kHz, at 0dBFS into 100k ohms (linear frequency scale).
It was only when I tested the 'A10's high-frequency intermodulation that I came across some anomalous behavior. Fig.7 shows the spectrum of the player's analog output while decoding 44.1kHz data from a CD representing an equal mix of 19kHz and 20kHz tones, each at -6dBFS. (The waveform of the combined tone reaches 0dBFS.) The 1kHz difference tone is very low, below -100dB, again implying the presence of an unflappable output stage. But look at the rise in the noise floor above 14kHz, which suggests a problem somewhere with this demanding signal, perhaps with the Re-Mastering DSP algorithm.
Fig.7 Technics DVD-A10, HF intermodulation spectrum, DC-22kHz, 19+20kHz at 0dBFS into 100k ohms, 44.1kHz sample-rate data (linear frequency scale).