DACs and bass response?

@worldwidewholesales What server are you using ?

Wow 800 psec of jitter would easily be audible. Even 20 psec jitter may be audible. This shows the importance of

1) A good modern asynchronous DAC that rejects the always present incoming jitter entirely - so you are left with inherent jitter of the DAC itself (for example Cranesong Solaris claims less than 0.5 psec jitter)
2) If you use a DAC that is not known for good incoming jitter immunity or rejection (perhaps a classic older DAC or something which just sounds good to you) then for goodness sake get Synchro-Mesh reclocker!

Be careful of asynchronous DACs that dont fully explain how they achieve a PLL. The very fact of gently adjusting the timing of a secondary clock to rapid fluctuations in the incoming clock can easily create low frequency jitter!! Some DACs have implemented a control filter on the timing adjustments that limit adjustments to less than 10Hz. Only a DAC that limits master-slave timing adjustments to BELOW the audible range (less than 10 Hz) can guarantee to eliminate all audible incoming jitter.

A poorly designed PLL may reduce jitter but create more audible jitter than a high level of random incoming jitter. The key is to understand that signal correlated jitter is much more audible than random jitter by several orders of magnitude. 20 psec jitter that is highly correlated could be much worse than 200 psec of totally random jitter. So a PLL may actually be a significant source of audible jitter!!! (sounds crazy but it is true)

Bass and power supply are linked in every way. This is because they share the same frequencies. The latest DACs are now using switched mode power supplies to great advantage at ultra high frequencies in order to get power supply noise far far away from the audible range. 

The weak link in any Linear Power Supply (no matter how massive) is that it runs on 60Hz (or 50 Hz) and this is a fundamental bass frequency!!!!!

@worldwidewholesales: RE: source, I plan to move to a server. For now, my Jolida cdp is no doubt, less than ideal, but this didn't keep the COS dac from serving up appealing bass. The difference between it and the Aqua were not subtle. What are you using for a server, BTW ? 

@shadorne: your technical understanding is way beyond me. I'm wondering if you could suggest some dacs that "limit (s) master-slave timing adjustments to BELOW the audible range (less than 10 Hz)". I will start paying attention to whether dacs I consider have switched mode power supplies. 

@mikelavigne: I wasn't suggesting that hyper-detailed dacs restrict the bass-- I was wondering whether they, in fact, might have the opposite effect. Sorry if that wasn't clear. 
   
 

@stuartk


As far far as I can tell, Weiss, Cranesong and Benchmark use similar methodology to handle jitter.

This article explains how digital processing is done on the Benchmark DAC2. There is a paragraph explaining how timing adjustments are done at always less than 1Hz in the Ultralock 2 approach. Note that adjustments are done in the digital domain which allows very small 4 psec tweaks.

https://benchmarkmedia.com/blogs/application_notes/inside-the-dac2-part-2-digital-processing

I have the DAC3 and it seems to do what they claim and Stereophile gave it a thumbs up recently as they did the Weiss DAC a few years ago.