Technics DVD-A10 DVD-Audio player Measurements part 2

Fig.4 reveals that the DAC has good linearity, any error remaining below 3dB to below -115dB. As a result, the Technics' reproduction of an undithered 16-bit sinewave at -90.31dBFS (fig.5) was excellent, if not quite up to the standard set by the best CD players—or by the expensive Sony and Marantz SACD players, for that matter.

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).

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