My First Digital Audio Player

One of the facts which people have been aware of for several decades now, is that we can buy a portable player, specifically for MP3 files, and that if we do, the sound quality will not be so great.

But in more recent years, Digital Audio Players have emerged on the consumer market, that promise lossless playback of high-fidelity sound, the last part of which is just referred to as “High Resolution Sound” by now. This lossless playback-capability does not come, when we listen to MP3-Files with them, but rather, if we actually play back FLAC, or ALAC -Files.

I just bought This sort of device, which is a Fiio X1 II. One of the remarkable facts about this device is, that its Digital-Analog conversion can run at up to 192kHz, and it sports the possibility of 32-bit sound. What I assume in such a case is, that even if I was to listen to a 48kHz -sampled audio file, 4-factor oversampling would in fact take place, because the D/A converter would continue to run at 192kHz, and I’d also assume that the analog filter would stay as-is, with a cutoff-frequency around 20kHz. But because I am in fact listening to 44.1kHz -sampled sound, I also assume that the whole D/A converter is being slowed down to 176.4kHz. ( :1 )

I have this working with My recently-purchased headphones, and am listening to a mix of MP3, OGG and FLAC -compressed music. I would say that this combination has significantly better sound, than the sound-chip in my Samsung Galaxy S6 phone does. ( :2 )

When I received this DAP, it had firmware version 1.6 already installed. But, I updated the firmware to the latest, v1.7… In fact, formatting the SD card with ‘exFAT’, as well as applying the firmware update, worked easily for me, even from Linux computers. The SD Card is a Sony.

My only regret is, that I personally, don’t have the manual dexterity which would have been needed to install the supplied screen-protector properly. I had the presence of mind to pull it back off, when it did not align correctly, and to dispose of the screen-protector. So I can expect some scuff-marks in the future. :-)

Happy, with Music,

Dirk

(Updated 07/09/2018, 14h55 … )

Continue reading My First Digital Audio Player

Sound Compression is also Possible, in the Time Domain.

One alternative type of sound compression which exists, is ‘FLAC’. This is a method which preserves all the information in the stream (later reproducing it exactly), which uses Linear Predictive Coding, and which Rice-Encodes the Residual, by which actual samples differ from the LPE-predicted values.

When I first tried to understand FLAC, my efforts were lacking, in that I did not know that LPE takes place in the time-domain, and not in the frequency-domain.

Dirk