STREAMER - WHERE DO I GO FROM HERE?

To the OP:  You’re just wrong about the potential impact of a streamer on SNR.  If you were right, streamers wouldn’t matter at all, and it would be fine to use your PC as your streamer.  I refer you, for about the 5th time, to actual measurements of this precise issue conducted by paul Miller.  He measured the SNR of an Audioquest Dragonfly using a PC as streamer: 94 db.  Then he measured the SNR of that same dac using a Volumio Rivo: 104 db.  So the pC added 10 db of noise.  No idea where you’re getting your ideas, but they’re just demonstrably incorrect. 

oh, and the pc was connected via usb (as was the Volumio).

Here’s the actual review:

Rivo review

There are numerous other examples, but the answer is the same.  Just  having a USB connection doesn’t eliminate all sources of noise from a streamer to a DAC.  Not sure why you’ve dug in on this indefensible point.  Really weird.

 

@mdalton wrote "There are numerous other examples, but the answer is the same.  Just  having a USB connection doesn’t eliminate all sources of noise from a streamer to a DAC.  Not sure why you’ve dug in on this indefensible point.  Really weird."

RESPONSE:  Hee Haw!  I was hoping we could continue this discussion.  This is fun. . .and you brought receipts!   You’re a stubborn one, ain’t ya?  I hope you didn’t drop your mic.  I thought that we put this matter to bed.   I guess not. Ok, now, thank you for that article which happens to support my position.   I’ll try not to publicly embarrass you.  That would not be polite;   however, it may be necessary in the interest of the greater good.   So. I apologize in advance:  I’m sorry.   <smile>

(For the audience, sorry for the spacing, but I type these extended responses in MS Word and paste them in.  I try to m ake my posts easy to read an coherent.) 

Now, give me your hand (again) so I can walk you through it, but first, let me restate my position:

1.  We’re discussing USB-oriented streamers connected an asynchronous-DACs (Specifically, the BAT Rex 3 DAC) through a USB connection.
2. My claim is that  “SNR is one of the least relevant factors when comparing streamers in revealing systems” because Asynchronous USB breaks timing dependency. The DAC’s internal master clock controls the timing—not the streamers.  So.  the streamer’s SNR, jitter spec, or analog noise floor cannot influence timing accuracy. The DAC sets the system’s SNR.  That is, the DAC only receives. data packets (aka 1s an 0s) which do not convey an analog wave form; Therefore, a streamer’s analog‑domain SNR spec has no bearing on what the DAC receives.

That’s a mouthful, but let’s move forward and discuss the article any why it supports my position.  Here we go (4th attempt):

The article shows that DACs with asynchronous USB + reclocking ignore the streamer’s noise/SNR

Hi‑Fi News explicitly states that with DACs like the dCS Vivaldi and Mytek Brooklyn, the Rivo made almost no measurable difference:  “both the dCS and Mytek DACs provide full galvanic isolation/onboard reclocking, so very little difference in their inherent ~10psec jitter was detected.”

This is important because—and I’ll say this again for clarity: 

• If the DAC is asynchronous, it uses its own internal clock.
• The streamer’s SNR, noise floor, and jitter do not pass through.
• The DAC reclocks the USB packets (those little 1s and 0s) and regenerates timing internally
• Therefore, the streamer’s analog‑domain SNR is irrelevant.

(Just call me a broken record)

The article shows that only adaptive USB DACs care about the streamer’s noise

(n.b. an adaptive USB is defined as a DAC that uses the incoming USB data stream’s timing as its clock reference.)

Hi‑Fi News shows a dramatic jitter reduction when using the Rivo with the AudioQuest DragonFly, which is an adaptive USB DAC:

• Jitter drops from 300ps → 135ps because adaptive USB DACs use the incoming USB clock, so the streamer’s noise matters.

This is the opposite of asynchronous USB.

Adaptive USB Is Inferior because the DAC is not in control of timing which leads to higher jitter, more sensitivity to USB noise, audible differences between transports, and greater reliance on the streamer’s electrical purity

This is exactly why the Hi‑Fi News Rivo measurements shows 300ps jitter → 135ps jitter improvement on the DragonFly and almost no change on asynchronous DACs like dCS and Mytek.

Uh, I won’t drop my mic because you may have more questions, young Padawan, which I’m happy to explore with you for your benefit that of those sitting on the sidelines eating popcorn.

This is great.  I love learning new stuff.  (Is that why you called me weird?) Sticks and stones, my friend, lol.  I hope you do too. 

If you still feel like your position is justified, then attack mine by poking holes in my argument.  Don’t just say that I’m wrong or weird. Please explain why. For example, "You’re weird because . . ." or stop digging. It’s ok to be wrong as long as you recognize and admit it.  That’s how me learn.

Hope this helps. 

That's 56 minutes that I'll never get back.

 

Lord.  And you started out so politely (many posts ago).  The irony here is that I actually believe that a good streamer shouldn’t cost much, that the differences among streamers are very subtle, and that in many systems, streamers are largely irrelevant if your DAC effectively rejects jitter, and also does a good job of filtering other noise.  

But the only question we’ve been debating is whether noise from a streamer can affect SNR at the DAC end.  And the answer remains “yes”.  I’m not saying it always does, I’m saying it can.  So for example the iFi dac tested by Miller has the same SNR -110 db - for both the PC as streamer and the Rivo.  That’s a case where you really don’t have to worry about SNR and your streamer.  But that’s not always the case, even with some really expensive DACs.  

Regarding adaptive USB, wrong again, the AQ Dragonfly uses asynchronous USB.  While typically that should result in negligible added jitter, that’s not an absolute.  

Finally, given that you seem to listen to AI more than actual people, here’s an AI response to the question: “Does using asynchronous USB from a server to a DAC eliminate all sources of noise from the server?”

 

“Short answer: No. An asynchronous USB connection does not completely eliminate the possibility of noise from the streamer reaching the DAC, but it reduces some types of timing-related issues (jitter). Other noise paths can still exist.

Let’s break it down. 🔍

What “Asynchronous USB” Actually Fixes:

In asynchronous USB audio, the DAC controls the timing (clock) instead of the streamer/computer.

• The DAC tells the source when to send more data.

• The DAC uses its own internal clock to convert digital → analog.

This helps reduce clock jitter that could occur if the source controlled timing.

So asynchronous USB mainly addresses:

• Timing accuracy

• Jitter from the source clock

It does not isolate electrical noise.

Noise Paths That Can Still Reach the DAC:

Even with asynchronous USB, several noise paths remain:

1. Power Noise via USB 5V

USB cables include a 5-volt power line. A noisy streamer (like a computer or cheap switching PSU) can send:

• switching noise

• RF noise

• ground ripple

into the DAC.

Good DACs often ignore this power line or regulate it internally, but not always perfectly.

2. Ground Noise

USB connects the grounds of both devices.

This can allow: • ground loops

• digital switching noise

• RF interference

to propagate into the DAC circuitry.

3. Radiated RF Noise

Even if the data is clean, the USB cable itself can act like an antenna carrying RF noise into sensitive analog sections of the DAC.

Why Many Modern DACs Handle This Well:

High-quality DACs often include:

• USB isolation chips

• galvanic isolation

• reclocking

• local linear regulation

 

✅ Bottom line:

• Asynchronous USB fixes timing/jitter issues.

• It does not guarantee electrical isolation.

• Noise from the streamer can still reach the DAC, though good DAC designs minimize it.