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I read one very interesting article from a Taiwan HIFI magazine a while ago. http://www.pubu.com.tw/magazine/音響論壇電子雜誌-第339期-12月號-83923 The editor interviewed five famous designers for their opinions regarding DAC design in terms of DSD and PCM Larry Guliman from MSB Andreas Koch from Playback Florian Cossy from CH precision Ted Smith from PS audio Robert Watts from Chord Till now, I realize that it might be a good idea to share it on CA and let everyone discuss further since I somehow disagree some of their argument points against DSD. However, I feel that people on CA always tend to be honest and offer sensible reasons. So let the debate to be continued. Since it's going to be a discussion thread, I try to avoid the first post to be lengthy. So I won't do the full translation of the article but list the bullet point of each interview's questions and the main general opinion of each designer. I will do the translation bit by bit everyday, hopefully. Alternatively, I can prioritize some part of the translation based on most people's interest. Please tell me the subtitle number of these interview questions. (Some questions are quite a common sense rather than meaningful ones) English is not my native language, but I will try my best to do the proper translation and if anything confuses you, please let me know. Here we go: Interview with Larry Guliman from MSB 1. General opinion from Larry: multi-bit ladder DAC is the purist passive DAC, in theory, it does not have any upper limit in terms of DAC speed. 1.1 What is ladder DAC? 1.2 How does MSB find the high-precision resistor? 1.3 What's the difference between Sign Magnitude ladder R2R dac developped by MSB and other normal dac? 1.4 What's the advantage of MSB ladder dac? 1.5 Nowadays, many DACs accentuate on the ability of 32-bit processing ability, what's the processing ability of your MSB select dac (ladder dac)? 1.6 The jitter of your FemtoSecond Galaxy Clock is very at 33 fs. What's the impact of it on the real music playback? 1.7 How can the FemotoSecond Galaxy clock be controlled to this low? 1.8 Is the internal FemotoSecond Galaxy clock better than external atomic clocks? 1.9 Select DAC uses hybrid dac to support DSD, how does it work? 1.10 What's the improvement of your new USB module? 1.11 Why does MSB dac use Analog volume control? Interview with Andreas Koch from playback 2. General opinion from Andreas: Rethink the nature of the DAC and how to completely solve the jitter problem 2.1 Your playback DAC convert files no matter PCM or DSD into DSD first and then do the D-A conversion afterwards, do you think it is a better way to do this even for the PCM signal? 2.2 Many people think only 1 bit DSD D-A conversion is the genuine and correct way to work, what do you think? 2.3 How does your developed 2D DAC work? 2.4 Do you really solve the jitter problem completely? 2.5 Do you think the external ultra-precision atomic clock controller is very effecitve? 2.6 If you claim that you solved the jitter completely, does it mean that the signal will not be affected anymore by any digital cables and digital interfaces? Interview with Florian Cossy from CH Precision 3. General opinion from Florian: The advantage of multi-bit R2R DAC will be fully revealed during music signal playback 3.1 Why does C1 use muti-bit R2R modulation instead of normal Delta-sigma? 3.2 Why does C1 still use pcm 1704 DAC chip? That chip has been released for quite a long time. 3.3 Why do you use 4 PCM 1704 chips on each channel? 3.4 Do you use your own DSP to do the DSD to PCM conversion? 3.5 Does C1's volume control also use DSP digital control? 3.6 What's special of your C1's clock? 3.7 Which is a better interface on your C1? USB or Ethernet? 3.8 Could you please explain your three-level analogue output on C1 in detail? Interview with Ted Smith from PS audio 4. General opinion from Ted: Only 1-bit DSD DAC can do the most linear, closest to the analogue D-A conversion 4.1 Before doing the D-A conversion on DirectStream DAC, no matter PCM or DSD signal, they are both being converted to the DSD first. Are you suggesting that DSD is superior to PCM? 4.2 Does it mean that the chips of some Delta sigma DAC are not 1 bit? 4.3 But many people think DSD dac has high-frequency problems, what's your opinion? 4.4 Are PCM signal being upsampled 10 times before D-A conversion? 4.5 It's quite difficult to do the DSD signal processing. However, DirectStream DAC uses digital volume control, can you explain how it works? 4.6 Don't you think the conversion between DSD and PCM will cause any distortion? Interview with Robert Watts from Chord 5. General opinion from Robert: DSD format has its native flaw while the PCM's limit is on the D-A conversion part, which can be solved by proper design. 5.1 Many people think by using the way of interpolation to do the up-sampling will damage the original signal, but the Chord always uses very high up-sampling rate, what is the intention by doing this? 5.2 What's the advantage of high-rate up-sampling? 5.3 What's so special about your Pulse Arrays DAC? Is it similar to Delta sigma modulation? 5.4 From Hugo to DAVE, your DACs all equipped with digital volume control, will it reduce the resolution at low volume? 5.5 Since Pulse Arrays DAC are multi-bit PCM DAC, are you suggesting that PCM is superior to DSD? 5.6 How does Pulse Array process the DSD signal? That's it for now.