KTONE Tone Board

By Khadas 115

KTONE Tone Board

The Khadas tone board is an amazing external USB hi-fidelity sound card that offers excellent performance and compatibility which will take customers' listening experiences to a whole new level.

This powerful DAC was made by integrating the advanced XMOS multi-core RISC microcontroller and ESS flagship 32-bit stereo mobile audio DAC ES9038Q2M into a tiny PCB. Next, three independent high-performance OPAs and four ultra-low phase jitter oscillators were added for the best noise reduction. Just as one would expect, each power supply path is powered by an independent, ultra-low noise power supply and the OPA is powered up to ±5.5 V.


  • XMOS XU208-128-QF48:
    • Eight cores up to 500 MIPS, with USB specifications
    • 32-bit mobile DAC with unprecedented dynamic range and ultra-low distortion
  • Very quiet power supply:
    • Ultra-low noise, high PSRR LDO
  • RCA connectors:
    • High-quality RCA output to deliver audio with tiny, clear, powerful, and rich sound details
  • Flexible I/O for supporting DIY Maker development:
    • Two RCAs for analog output at 2.0 VRMS
    • Eleven RCAs for S/PDIF in or out
    • One 30-pin FPC connector for 8-channel analog output extension
    • Two 10-pin FPC connectors for OLED display and I²S extension
    • One 40-pin female header for connecting Khadas' VIM SBCs
    • One 20-pin SMT header for debugging XMOS and Khadas' VIM SBCs
    • Makers can build their dream "SBC + DAC consumer product"
  • Accurate low-noise clock:
    • Ultra-low phase noise crystal oscillators with superior phase noise characteristics
  • Performance parameters:
    • THD+N ≤0.000337%: barely hear the distortion over the THD+N signal ratio
    • SNR ≥120 dB: hi-res audio systems require an SNR ≥110 dB
    • DNR ≥120 dB: high DNR lets consumers hear a wide range of subtle sounds; the sense of space and layering is like a live concert
    • Crosstalk (channel separation) ≥127 dB: high crosstalk separation creates stunning stereo effects
    • Frequency response ±0.08 dB: tone board has a very even frequency response across the entire audio spectrum
    • Ultra-low phase noise clock jitter: the SiTime SiT820&8209 oscillator is used as a reference clock in the DAC, keeping data clock jitter <30 ps
  • OS and audio format compatibility
  • OS compatibility:
    • Linux, Windows, Mac OS, Android, LibreELEC, and Volumio
  • Lossless audio formats: