.? Digital Reclocking and syncing clocks does anyone know the correct Answrrsb

LordMelton  you are correct your 👂 ears are the best measuring tools 

graphs and specs do count when designing ,but there is ways to smooth out a ripple or spike ,and smooth things with oversampling FPGA ,the final result is how does it sound  to reality ,and your audio system ,as well as room will influence the sound .Sound is just a movement of frequency in the realm of time .

The Moody Blues Classic nights in white satin  in the orb summed it up best - We decide which is real and which is a illusion  !!

one thing is for sure the best measurements don’t always sound the best .

A perfect example A vacuum tube amp,or preamp measure no where near as good as even a mid fi amp but it’s distortions being even just sound right to the ear 

I am always wary of entering this swamp, but the huge elephant on the table comes from music theory - dissonance and consonance.  Its just plain mistaken to correlate " enjoyment" with "lest distorted, overall.

1. People's tastes differ

2. People's hearing differs.  Many in our (and i step into muck here) hobby are old men and have high frequency hearing loss.  Is a flat response best for them?  BTW many old rockers have tons of HF hearing loss and IMNSHO master records accordingly.  bright!

3. Consonant distorion can sound good.  Its disortion, but enjoyable.

4. Dissonant distortion sounds awful.

5. Corollary to 3 and 4 - ideally we would have a weighted measurement of distortion - reducing or eliminating the weight of consonance and vice-versa.

6. Now, if ALL distortions go to zero, or close, we ought not to be able to hear them. But #1,2 above might complicate that assertion.

I have spent 30 years trying to find measurements that lead me to better sounding designs. I have a few. I also have a bigger library of design tricks that produce good sound, but i cannot always measure why. My stuff has adequate measurements for THD + noise, but compared to a super opamp like a 49720 or 1612 they suck ( that's a technical term).  So back to Daniel and his quote..... (from many posts ago).

Anyway, for all this I may surprise many in that i generally prefer digital to analog, and get great results, by paying attention to basics.

What I meant to say is  the digital stream is never perfect, But the much more costly units  have many ways to correct Jitter or timing errors ,

What  you are saying is wrong. There is no jitter on USB of Ethernet inherent in the data transmission. None, nada, zip. There is no jitter or timing errors to correct. That is why low cost DACs, literally ones that cost <$200 are able to do THD+N, SNR <-110db, and IMD, even multi-tone IMD at very low levels.

Even with SPDIF, those DACs are able, though PLL receivers and any number of chip based methods reach SNR, THD+N, etc. <-110db. They will even do it with TOSLINK.  Cost means nothing. There are a lot of expensive DACs that can't do that. Think of how much experience, and knowledge goes into those DAC chips.

this too is where a DDC  -Digital to Digital converter to clean up the incoming digital stream and eliminate timing errors before it goes out to the dac , the easier the dac can read the less error correction s needed , On the better units they buffer the signal ,like ram  ,there there is FPGA  ,it’s exact implementation is above my Digital 

FPGA is just a bunch of fast digital logic. It has no inherent advantage. There is nothing to clean up with USB and Ethernet, and again, with SPDIF, if you are already <-110, or better, what exactly are you cleaning up?

@itsjustme , by Consanant and Dissonant distortion, do you effectively mean harmonic distortion and intermodulation distortion?  I could see dissonant distortion also meaning aspects of unpleasant harmonic distortion.

When those distortions go close to 0,we don't hear them, but you are correct, we may not like the result. Some people like tone controls, and distortion can also be used to affect tonal balance in a pleasing way. I actively play around with added distortion on my setup, preferring it with some music/listening levels. I just do it in DSP so I can turn it on/off.

The LM49720 does not suck. It a properly designed circuit, it is a straight wire with gain effectively. The THD, IMD, noise, etc. is low enough to be difficult to measure. The 1612 is similar. Put it in the wrong circuit, and conceivably it will have issues. They do what they do. They do it very well .... but .... no matter what they claim, a large portion of audiophiles don't want a faithful recreation of the recording, they want something different.

In my new Denafrips terminator-2 it has A Ton os superlative parts , massive 

power supplies, excellent top notch filtering-Swiss Elna Silmic capacitors,

as well as SuperCapacitors , O core transformers , pre buffering, FPGA 

$$ Dual frequency 45,49 MHz Oven controlled clocks , and  I read the report on the Gaia ddc,  I am using the lesser Iris and it bypasses the ddc clock for the top Terminator-2clock , this mk2 model is just a few % points ofthe T+ model .

it is identical on 98 % j. Just a few more smaller filter caps .

and using good cables ,using Wireworld best silver sphere Hdmi-I2S , and silver starlight 75 ohm BNC cables to sync master clock in T2 you can clearly hear the difference in coherence. All 5 of my guests heard the difference with ease 

@cindyment

I mean both IM and unpleasant harmonic distortions (i prefer to simply use the musical term dissonant so that it is better understood). I leave that definition to music theorists and psychoacousticians.

reference for those who wish to dive in.

The 49720 does not suck at all. Those two chips are among my favorites, for musical amplification. Re-read read what I said: I stated that the % THD+noise measurement of my own designs, in comparison, "sucks". Meaning since amusing language seems lost here "is substantially higher in aggregate measured by FTC methods" (which i think are misleading, to normal consumers, for the reasons i stated)

But, maybe the inference needs to be stated: My custom designs, higher levels of total distortion and all, sound meaningfully better in many respects. Perceived dynamics being the most obvious.

Why? You tell me. I have some educated guesses (and no, on those, I’m not talking)