Yes, it's a complex subject, and I am sure I did not do enough to simplify the concepts and start with simpler examples. I had some time off and just getting the Python program running and working through the first few examples consumed way more time than I expected. Someday I may try to go back and tighten things up but for now it is what it is... For now Life and Work is ramping up (new parts coming in to test at work, older son getting married in a few weeks, so we're pretty swamped).Hi Don, really sad to see a so low resonance of your thread. I guess the problem is you did not give a simple answer. Most people think in simple solutions and not in more complex possibilities. Hopefully I'm wrong.
My equipment list is in second link in my signature, the one starting with "My system:". I don't have a high-performance DAC or streamer. My schedule rarely permits time for serious listening; maybe in another 147 years when I retire.Don, thank you for this. I didn't see in your "signature" what components you are using in your personal system. If you could suggest a few sets of components for a 2 channel system that would work well i'm sure a lot of us would be very grateful. You would NOT need to include speakers but rather just use a generic 90db speaker to make things as simple as possible.
As an example, would this be an appropriate starting point for an excellent two channel streaming setup:
digital streaming source:Benchmark DAC3B:Benchmark LA4:AHB2 (stereo or mono depending on power needs)?
For the purpose of this discussion we'd have to keep room correction, bass management and speakers out of the mix.
Jitter adds noise to the output of a DAC (or to the samples of an ADC). There are many types of jitter but for audio typically we talk about random jitter, though clock noise can introduce correlated (non-random, fixed) jitter, so high jitter just adds to the noise floor. Check my signature for a link to my technical articles on ASR for several threads that dive deeper into jitter and other sampling ("digital audio") related topics. Jitter is a huge topic all by itself. The introductory threads on DACs are a good start.Thanks for all this work, this is very helpful for a layperson like me.
Dumb question, but hopefully a simple answer for you. You hear a lot of talk about 'jitter' in the audio world; as in something that creates usually small but audible timing distortions in the reproduced analog signal. In the way you are presenting this summary, can I think of jitter as basically noise, or related to noise, so that's picked in up in SNR? Or perhaps distortion and so it's captured in THD? Or does that not make sense and it's a wholly separate concept?
I ask because I wonder about the virtues of these devices that claim to eliminate or reduce the effects of incoming jitter, which perhaps is another way of saying they can eliminate or deal with incoming noise. I guess that should be measurable if an audio device outputs a signal with less noise than the incoming signal, and yet I've heard people claim that jitter is not always picked up in measurements like THD or SNR.
A related question, even if we had perfect THD, SNR and SINAD measurements for all stages of the system including speakers (I know this is impossible in real life), how confident can we be that we are capturing all the distortions that affect the audibility of the sound coming out of the speakers (disregarding the post-speaker chain like speaker placement, listener hearing issues, room treatments, etc.)? Just trying to better understand the limitations of these measurements.
Understanding Fourier takes some study, but most folk understand a frequency plot and mange to get the general idea.Thanks very much for the response. I'll have to educate myself on those references.
This article is helpful for someone like me, because a meaningful technical explanation does far more for me than someone just blindly asserting that I'm not hearing what I think I'm hearing. The problem is to understand what you are trying to say, you really have to dive deep into the technicalities. I mean, Fourier analysis alone takes most people weeks of study to appreciate, even with a year or two of college calculus under your belt.
The problem you face is the people who sell this stuff often have simpler explanations that seem to make intuitive sense. For example, with the jitter point, they'll say something like "Of course we're not saying bits aren't 0s and 1s ultimately, but you know timing matters. It's not just about whether all the bits get there but whether they all get there at the right time! Even a slight delay will affect things like spacing of the soundstage." And that sounds plausible to many people. E.g., I don't think I appreciated what exactly SNR and THD measurements mean until I read your article, and that, yes, they should pick up these kind of timing delays. (Although to be fair I'm still not sure why only the sum of the 1st 10 harmonics is used in THD and whether this has any implications for the measurement, but I also haven't yet read the posts you cross referenced when you mentioned that).