Mark Levinson No.39 CD player Measurements part 2
Fig.4 Mark Levinson No.39, balanced mode, departure from linearity (2dB/vertical div., right channel dashed).
Fig.5 Mark Levinson No.39, balanced mode, waveform of undithered 1kHz sinewave at -90.31dBFS (16-bit data).
It was not possible to measure the '39's jitter performance. However, Stereophile has recently acquired a Paul Miller analyser, which will allow us to measure the effects of word-clock jitter in the analog domain. We will look at the '39's performance in a Follow-Up.
Regarding distortion, this was very low. Fig.6 shows the spectrum of the Levinson's output while it decoded the 0dBFS 1kHz tone on the CBS Test CD at a 4V output level. Odd harmonics predominate, but these are all very low in level. The load for this measurement was a punishing 600 ohms. Increasing the load to 100k ohms dropped the level of the even harmonics but left the odd harmonics alone. Finally, fig.7 shows the player's output spectrum while it reproduced a full-level mix of 19kHz and 20kHz tones into 100k ohms (this is the audio equivalent of CU's infamous automotive slalom test). The 1kHz difference tone is at a very low -100dB; while the 18kHz and 21kHz second-order tones rise a little higher, these are still below -90dBFS.
Fig.6 Mark Levinson No.39, balanced mode, spectrum, DC-22kHz, 1kHz at 0dBFS (4V) into 600 ohms (linear frequency scale, 20dB/vertical div.).
Fig.7 Mark Levinson No.39, balanced mode, HF intermodulation spectrum, DC-22kHz, 19+20kHz at 0dBFS (linear frequency scale, 20dB/vertical div.).
Summing up, these measurements indicate the No.39 to be a superbly engineered design. Digital doesn't get much better than this!—John Atkinson