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
Look at it another way. We spend a lot of tiem money and effort looking for things to fix. Wouldn't it be good to have a dac that turns red if a particular source is no longer performing well?
I mean, if we hear something change, we often look for cables, power conditioners, or even room acoustics (which are always important!)

I'd love to have a little light saying "Man, it is really hard to lock onto this device now."
Best,
E
Erik, signal lock LED’s exist on DAC’s and reclockers. It’s pretty much a -/+ indicator, tho. 
@celander Exactly.

To answer the question about what we would use externally, jitter, noise and distortion measurements. I don't think we need to have all that test gear in place though.

For instance, there's circuitry which is making choices about adjusting the DAC to the incoming signal. Knowing some basic statistics about that. Like, what is the incoming long term variance? How often are there outliers?

The complicated view techs might see could be reduced in my mind.

I know at least one DAC even claims to compensate for impedance mismatches, so this must be measurable.

Best,
E
Alternatively, maybe this should be a gadget? Why am I telling you guys all my best ideas ?

Best,
E
Erik, I presume one could adjust the sensitivity of the LED indicator (or use a multi-colored LED) that reports distinct levels of jitter. Seems like one would need some sort of jitter level sensor on the output digital stream just prior to final analog conversion. That sensor could be calibrated to feed a signal to the LED to indicate jitter level. Not convinced that the DAC jitter reduction would not overwhelm whatever jitter level you’re trying to detect in the input cable. But presumably one could put a similar sensor on the input side of the DAC input circuit.