With the compliments of the Elektor Labs and Editorial teams, here comes another previously published article that's free to download by all registered Elektor e-zine readers. "Free Back Articles" are published at two-weekly intervals in the Elektor e-zine, alternating with "Free Fresh Articles".
  • Original publication: Elektor magazine issue 1/2018 on page 44.
  • Author: Falko Bilz
  • Free download expires: Friday 31 January, 2019.
  • Original article production number: 160460
  • PCB available: yes, see Products below

Note: Since its publication of the project in 2018, components, software elements, webpages and other elements mentioned in the article may be subject to updating to the present day.


With a smartphone or an MP3 player it’s easy to play audio files, but generally not at room strength or if you can, only in wretched quality. The Card Sound project makes it possible to fill the room with music and have excellent sound reproduction! This lightweight and compact player also stands out for its modest quiescent current consumption and desirable extra features such as I²C and RS-485 control.

Quick Features of the Project

  • Analogue/digital supply voltages: 3 to 18 VDC / 4.5 to 12 VDC
  • Analogue/digital current requirements: see Measurements panel
  • Sinewave output power Pout into 4 or 8 Ohm: 12.5 W or 6.25 W (measured at 10.0 V peak-to-peak)
  • Output: short-circuit protected max. 2 A
  • Harmonic distortion: see Measurements panel
  • Zero-value noise: around 1.4 mW
  • Data formats: PCM 16, 24, 32-bit for each of 32, 44.1, 48, 96, 128 kHz Stereo
  • Dimensions (L x W x H): 89 x 33 x 30 mm
  • Weight without SD card: 26 g
  • Figures valid with a supply voltage of 5 VDC (digital) and 12 VDC (analogue) for a 1 kHz sinewave signal with 16 bits and 44.1 kHz sampling rate

Selected Images


Like what you’re seeing? Then go to the article page and download a pdf copy of the full, original article. Downloading is free from Friday 24 January to Friday 31 January 2020.