RD160 external clock inputs

ROSE Products RD160
#41

You missed some of the data raised in this conversation.
You can’t just look at the clock itself and say look that femto scale clock has a stated jitter rate of 200 femto seconds so its a non issue.

The reviewer who tested the Rose RD160 showed the graph of the test signal of 1kHz. The graph shows a pair of peaks at -50db. If there was no jitter there wouldn’t be those peaks or rather that noise would occur at a much lower db level.

The point is that its not just the clock but everything around it. The clocks are fairly accurate, yet when you see that graph and the jitter you start to realize there’s more than the clock and that jitter has to be considered in context.

And yes Bonte I know what a cello sounds like in real life. Not just the recording but the fingering and bow of someone playing the Bach Cello Sonatas. Which is why I talk about being able to hear the fingering. (And some of the bow work.)

#42

Just to add.

HERE: is a graph off Ian Canada’s website showing you a graph of the noise from the clock.
At 1kHz the noise from the clock is less than -160db, where anything below -80db is considered outside your hearing range.

Note this uses an SC cut crystal. (Which you can do some research why this is important.)
As to highly accurate external clocks… you could buy one for around $550 USD on AWS. You can see one HERE: .

#43

Hey Mikey, you’re splitting hairs!

If the DACs are built differently from the ground up, you might be able to hear a difference. Let’s say, for example, they share the same master clock (a high-quality one, naturally :tired_face:) but feature different chip architectures—like Sabre versus AKM. In that scenario, I’m right there with you; You wouldn’t even recognize the cheapest DAC from Walmart if I did a proper A/B test with you (well, maybe the cheapest DAC is a bit of an exaggeration), you can already hear a difference.

But I’ll bet you this: if everything is synchronized and properly level-matched (volume, etc.), you won’t hear any difference between a WiiM Amp Ultra and your 520—provided, of course, that we are comparing only the chip architecture and the master clock. I’m not talking about the amplifier part, etc., etc., lest I get any more strange answers.

#44

That’s not what I meant. I’ve heard a cello before, too! But every cello sounds different! Just like with DACs. How “a” cello sounds depends on the builder.

What I meant was—let me say it again for you; specifically for you:

How do you know which cello was used in the recording? You have no point of reference—if we’re going to start splitting hairs here!

#45

There are two things.

First, I’m not splitting hairs.
When you search out for reviews on the rd160, you will see where someone did a measurement and calls out a 50ns jitter.

Now if you were to use a master clock and run the same test… in theory… you wouldn’t see the sharp points that are -50db down, but would see them at a far lower db. I say theory because I don’t know if anyone has done any sort of testing to show this. And again this is a 1kHz signal. The author of the review uses the term jitter which in context is different than the clock jitter itself. (Now if you are a technical geek, you can look at the oscillators involved in the clocks to understand why different clocks have different levels of accuracy. (e.g SC cuts )

And to the point of having these femto clocks that have jitter values in the 200fs range… you would think that its enough, however when you go back to the graph… -50db is audible to some people in certain conditions. That is where you get the smear or loss of detail.

I prefer to listen to cello because as a wee lad, it was what I learned to play.
Yes each cello can have a unique sound. As does the musician. But that’s not what you’re listening to.
You’re listening to the fingering and bow work in order to hear a crisp clean sound. A musician may tap the string against the fret and you will hear the click and a little bit of reverb. You may hear the strength of the start of the down bow movement. (Pulling the bow back towards you )

The point is that you hear it.
At the end of Cello Suite 3 part II you hear the bow lifted and then the reverb of the strings. That crisp sound.

If you know the piece, you know what to listen for. It doesn’t matter if the cellos are different or if the musician is different. Any professional musician will play the piece roughly the same. You’re not comparing the musician but are looking for specific sounds when the piece is being played.

Got it?

And yes, you can hear a difference between a WiiM amp and the RS520.
The WiiM can’t really drive the Mon Acoustic mini mons. Now if you were to find speakers that both speakers can drive… like the Philharmonic BMRs depending your hearing… you can hear a difference too.
The amp itself. Different Class D architectures.

As much as we beef about the software and some of the features or lack of… the sound of the Rose gear is still pretty good.

#46

In my post I was also referring to a theoretical test. Thanks for not correcting me right away this time. :wink:

You keep talking about measurements and how one can “see” the results. You know, we discussed this topic in my chat, which was then blocked. I belong to the “measurements camp,” and so do you; but can we—at our age (you over 60, and me 55)—actually still perceive those measured signals with our hearing???

Speaking of jitter…

I called Lyngdorf in Denmark to ask what kind of master clock they use and what the situation looks like regarding jitter.

Anders von Lyndorf told me not to worry.

Me, well, why not?

Anders replied:
“If jitter couldn’t be prevented, you’d hear a cuckoo coming from the speakers every half and full hour—just like with your cuckoo clocks back in Germany!” :crazy_face:

Cuckoo… :ear:t2:… Cuckoo… Cuckoo… :laughing:

#47

Bonte,
There is what you hear aka a listening test.
And then measurements.

You will want to do both, and in the end, you should rely on what you hear and if you like what you are hearing.

In terms of measurements… you can see that there is jitter. Is it from the clock itself or the implementation.

Again, I’m not the one taking the measurement and I don’t know of anyone who has taken two sets of measurements to show that there is a major difference.

At the same time… when a measurement shows that its below -120db… and you claim to hear it… I’m skeptical . If you can take an external clock and do the test to show the reduction in the jitter on a 1kHz signal and that the reduction move the needle from -50db to over a -100db… then the external clock makes a difference.

As to hearing… over the last couple of hours I’ve been working on fine tuning my recording settings for my video recorder and trying to work which mic works best. So yeah, my hearing is fine, better than many at my age and remarkable in that I used to spend a lot of time around things that go boom/bang.

And no, its not about preventing jitter but moving to a level that you can’t hear.