An Interview With Dafydd Roche

Welcome, Dafydd Roche of TI and ExpatAudio!

• • Dafydd works in the audio group at TI as a definition engineer. One example product is the PCM1865, also discussed on /r/nicechips
  • Almost all chips need to be marketed for the mass market now, not single customers.
  • Rule of thumb: Number of bits * 6 = dB of range
    • 24 bit = ~144 db of range
  • The eardrum tightens when subjected to loud noises.
  • Zipper noise
  • Dafydd has a side business with another UK expatriate called Expat Audio.
  • He has an ECM93 Pick and Place machine. Another rule of thumb is if you're not going to use the machine weekly, it's probably not worth it.
  • Hardware controlled chips are easier because it just takes resistors to set functions on the chip (no FW)
  • Development boards allow engineers to try out new features by "blue wiring it in"
  • Peak Music Power Output - PMPO
  • Watts are often listed as a percentage of THD.
  • Speakers are 1%. Additionally, toom accoustics will ruin the best speakers
  • One of the parts Dafydd has helped design is 600W single chip amplifier.
  • NPR did comparisons on bit rates to show that most people can't hear the difference. 
  • 1V RMS signal w/ 130 dB range...ends up being tens of nV at the low end of the scale. 
  • Henry Ott was on the show, Dafydd loves his book.
  • We asked about the low material chip packages, in case audio could have the same problem as the Xenon flash bug for RPi. Dave did a video about this:
  • Future projects will be remote control of analog, recall setups using storage.

Many thanks to Dafydd for being on the show, you can reach him as @ExpatAudio on twitter and on their FB page