2. digital
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Things I don‘t know

Digital is very much an emerging transmission form and there are a few questions where I simply don‘t know.

1. In the digital domain it is very easy to shift polarity of recordings and the effects are very audible. Yet few devices offer the capability even in very high end systems. Conversely it seems a standard feature on software for computer based systems. This matters greatly since probably half of all recordings are made out of polarity.

2. In digital accurate clocking is of paramount importance to achieve good leading and trailing edge definition as well as spatial rendition. Yet few Dacs even in high end devices and even fewer streamers or switches offer 10m clock interfaces.

3. Even small RFI/EMI or ground level intrusions are very detrimental to accurate D/A conversion. Yet most Dacs still don‘t provide galvanic isolation on their inputs and often claim to address the issue with error correction in the digital domain. Do designers simply not know better?

4. Recent advances in Class D amplification seem to point the way; yet there seems to be no consensus on optimal sample frequency nor power supply design for these devices.

Finally, while rare exceptions like @atmasphere see their task as clarifying and educating on the issues, the vast majority of designers either don‘t make the effort or just go about shilling their widgets.

While I am sure that this is only the beginning of a list of digital issues worth discussing,the usefulness of Audiogon Fora rests precisely on elaboborating and clarifying on all issues immanent in this new approach to things and in most instances the issues don‘t at all relate to issues discussed purely in the analogue domain.

antigrunge2
yoyoyaya's avatar
yoyoyaya
734 posts
 

On Clocks

Very few DAC manufacturers e.g. Esoteric and DCS, make their own clocks and most manufacturers don’t want you going off and buying someone else’s product. That’s aside from the fact that digital designers do differ in their views of the relative merits of onboard and offboard clocking.

 

mike_in_nc
1,147 posts
 

I used a Mutec reclocker for a while. It helped an older piece of gear appreciably, at least to my ears, but the reclocking degraded the sound of a newer, better (but less expensive) piece. Why, I don't know.

The main use of external clocking (other than profit) seems to be in sound studios with numerous pieces of gear that need synchronization. That's why consumer gear rarely has clock inputs.

antigrunge2 OP
1,400 posts
 

@mike_in_nc 

Did you just use an M3 or a ref10? makes a big difference

mike_in_nc
1,147 posts
 

I had an MC-3+ Smart Clock USB. The REF10 is more than I was willing to pay for something that I might or might not consider an improvement. My conclusion was that differences caused by reclocking will be system-specific (a pretty bland and safe conclusion).

Those interested in the subject might look at this 2010 comparison of clocks in the pro sound journal Sound On Sound. It said, among other things:

There's a widespread notion that adding a high‑quality master clock to a digital system will somehow magically improve its overall performance. While that might possibly have been the case in the very early days of semi‑pro digital converters where, frankly, some of the internal digital clock designs were pretty ropey, it certainly isn't the case today. . . . Today's converter designs generally work best on their own internal clocks, and most will deliver a slightly poorer performance when clocked externally. The very best devices will show no change in performance at all, because they have superb clock-extraction circuitry that can remove all traces of clock jitter and other external clocking artifacts, so they work just as well as when running on their internal clock.

As always, the questions are: Is there a difference? Is the difference an improvement? Is the improvement worth the price?

atmasphere's avatar
atmasphere
11,784 posts
 

1. In the digital domain it is very easy to shift polarity of recordings and the effects are very audible. Yet few devices offer the capability even in very high end systems.

@antigrunge2 We've had a polarity switch on our preamps since their inception in 1989. Its a simple matter of swapping the phases. Most of the time you can't hear it; your best chance is with a true stereo recording that used only a stereo microphone pair. So forget 99 44/100% of all rock recordings. 2-mic recordings are more common with classical, jazz and folk but by no means is universal.

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