DAC's : The missing feature: Signal quality


One thing I wish DAC's would provide is some idea of how much jitter and noise a particular input provides. This is something which I think with a little work could be gleaned from the input circuits.

I want something that tells me "woah, that's a really dirty signal coming in, but i"ll do the best I can with it."

One common source of noise is ground loops. Another may be high jitter from a source like Apple TV. This would also help us evaluate the benefits (if any) of various signal cleaners and reclockers.

Best,
E
erik_squires
The reason this is not common as it’s not really needed.

No one has any idea if this is needed or not because end users never get to measure it themselves. The argument here is really that unless it's blatantly obvious to the ear we should not care. To those people I ask: Do you even buy high end equipment?

I've read a number of reviews, and experienced enough variance in performance of sources to know that this is not the case. Having some sort of Green/yellow/red indicator about signal quality and noise I think would be helpful. For instance, there are a number of reclockers and signal cleaners on the market. Wouldn't it be nice if our DACs could indicate directly if a particular source might benefit from it?

Like, green on CD player, green on streamer, but woah, that AppleTV signal is a mess.

So pick your place. Bits are bits and unless the signal drops out I don't care, or I care about signal quality and would like to know if I'm missing something important.
Best,
E
If your system has jitter (only thing to take note of for digital connections; linearity, THD, crosstalk, IMD, SNR, etc. are all near identical), then that results in a rise in the noise floor, which would sound like static, it would be heavily masked by music, but if you played say a 10kHz tone on your digital device, and you heard some background static, then you have audible jitter.

We are talking random jitter here (not periodic), and if you want an example of what poor random jitter sounds like as a reference point:

http://www.sereneaudio.com/blog/what-does-jitter-sound-like

Take note of how 2ns of random jitter raises the noise floor to ~ -80dBFS, and keep in mind how I said even cheap DACs can reduce it to -100dBFS or lower (+20dB is the same as having 100x more wattage, so in this case 1/100 the wattage as it’s the opposite direction).
Ugh.

Julian, wouldn’t it be easier to simply provide folks here with a link to your pontifications? smh

Hell, I’ll do it for you to spare the suspense for everyone concerned:
https://forum.audiogon.com/discussions/why-does-my-dac-sound-so-much-better-after-upgrading-digital-...


@erik_squires Erik-assuming that you are talking about some kind of user interface that displays a reading or some LED array signifying such problems, what kind (and cost) of test equipment (outboard) would normally be used to ascertain such things? 
I can understand the op’s point of view. If it was an easy thing to do.. It might be good. I have no idea how hard it would be to implement? But as some have mentioned, the end result is already there. Plenty of folks can just hear (the result in the final sound) the input stream is not as good as another. So they already know.
Like when I bought on multiple recommendations, the Lifatec Toslink cable to connect my favorite five disc changers to my DAC. Yes it sounded ’better’. What else did I need? Proof? Why?
On the other hand if the DAC came with an easy meter or? and I could then come here and say Why yes the Lifatec reduced jitter 16% over my previous glass medical Toslink. ???I would think a stand alone device would be more appropriate. But who would PAY for one? if it cost $3000? even $300?