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Performance

I performed my tests of the Zen Touch audio-player in two stages: audio output quality and speed characteristics.

The first test – the quality of the player’s line-out – was performed with the help of SpectraLAB utility. I created two etalon audio-files in SoundForge especially for this test stage. The first file contained a 1kHz signal to determine the basic audio characteristics of the player; the second had two tones at 250Hz and 8020Hz frequencies for evaluating the intermodulation distortion coefficient. Both files were copied to the player’s drive and reproduced from there.

I pushed the player’s volume control to the maximum to see if the device is usable in this mode. Many players produce strong harmonic distortions at the maximum volume levels – this spoils all the fun, of course. Unlike them, the Zen Touch had no distortions at the maximum volume; the sound was clear and translucent, and powerful enough to silence the noise of the underground or street. But let’s get back to the tests…

The reproduced signals were measured at the player’s line output and were transferred to the input of the Creative E-MU 1820 professional-class sound card. The spectrograms follow:

  • SNR: 83.4dB;
  • THD: 0.00672%;
  • THD+N: 0.00676%;
  • IMD: 0.0021%.

The tests confirm that the player has a very low noise level, although the measured SNR value is somewhat above the specified one. The spectrogram shows that this parameter is worsened by the surges at 3 and 5kHz frequencies. The rest of the noise, however, is after the -100dB point, which is a good result for any player.

Next, I tried to estimate the real data-transfer rate when you use the player as a portable hard disk drive. Due to the above-said reasons, I had to install NOMAD Explorer and measured the file-copy time with an ordinary stop-watch. Knowing this time and the total size of the files (5.8 gigabytes) I calculated the data transfer rate when copying onto the player. It was 5.74MB/s. That’s a good speed – the high-speed USB 2.0 interface shows its best here!

I also enjoyed listening to the player much. To make my opinion about the sound quality, I used digitized tracks from the IASCA Competition CD. The player would be excellent if used as a music box with some speaker system. Overall, there are more positive points about this device than negative ones.

 
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