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

How NOT to control our Gaming Keyboards, from a Linux computer.

One of the commodities which serious computer enthusiasts might want to buy, is a gaming keyboard. One reason may be the fact that by coincidence, gaming keyboards tend to be sound mechanical keyboards as well, which have per-key switches, which in turn have the desired tactile response, which bubble-keyboards today often lack.

But then, one of the features which gaming keyboards may add, is the ability to store and play back macros when in gaming-mode, those macros being key-sequences which a player needs to enter repeatedly, but tires of typing each time.

Another feature gaming keyboards can have, is fancy LED back-lights, which can even be customized to highlight different groups of keys, depending on how those groups of keys are important to certain uses of the KB. ( :1 )

I just bought the “ThermalTake eSports Poseidon Z RGB”, with Blue Key-Switches. The blue key-switches are switches that not only give good tactile feedback, but also make a distinct, high-pitched clicking sound, at exactly the right instant, during a key-press.

They have mechanical hysteresis.

One less-optimistic side-effect for this, under Linux, is the fact that some of the customization of this KB requires that proprietary software be used, of which there only exists the Windows version. The main functioning of the KB will work under Linux (Debian / Stretch), but if we want to program the layout-coloring / highlighting, then we need to use the proprietary software. These layouts can then be stored in 1 out of 5 Profiles, on the KB itself, which has its own 32-bit embedded micro-controller (i.e., this KB has its own CPU).

I tried to find out, whether I could install the software under a specific Wine folder, and then create symlinks to various device-files that exist natively under Linux, so that those device-files will appear as generic, DOS-type serial ports. Since Wine, by default, does not have direct access to the host machine’s USB-connected hardware.

The result was, that I bricked the keyboard. I needed some support from the retailer who sold me the keyboard, to recover a fully-functional instance.

The sum total of what this means, is that I can use this KB under Linux. I must just store its customizations using an old Windows laptop I have – a dual-boot ‘Acer Aspire 5020′ – after which I can disconnect the KB from that laptop, and connect it to my main (Linux) desktop again.

(Edit 04/05/2018 : )

foxy_152296964773

(One problem with trying to photograph this keyboard with a simple phone-cam is, the fact that the LEDs produce light with high intensity. This light tends to saturate the light-sensor in a conventional camera-phone, which in turn results in a reduction, to the recorded color saturation. I.e., when the BG light-level is normalized by a camera-phone, the brightest primary colors are off-the-scale, but limited to scale as encoded.

Therefore, Blues will seem to look similar to Greens, and Yellows look similar to Whites.

When seen with the naked eye, all these colors look very deep. )

 

Continue reading How NOT to control our Gaming Keyboards, from a Linux computer.