Rossini clock questions

Sorry I’m a little confused on the Rossini clock and was hoping to get some clarification. There is very little info in the manual or anywhere about the clock and what it’s doing to improve the sound.

  1. so if I’m reading this right the clock would serve no purpose if you were playing CDs in a transport and hooking to the Rossini via SPDIF? That is what I’m deciphering from the manual. Same goes for regular AES input. The clock would serve no purpose.

  2. I was getting some occasional digital noises and it was driving me crazy. I tried all kinds of different settings and it was doing it wether I was streaming or playing back via CD transport. I set to audio for wordclcok via CD transport and auto when streaming via ethernet. I have the clock off now and I’m not noticing any noise.

  3. It’s even clear to me if you are supposed to have buttons on the from of the unit on or not. I’m not even sure what those do. I bought the unit together with the DAC and never really questioned it’s validity but now my sound seems to be doing better without it. I mostly play CDs via SPDIF. It sounds a lot better than my streaming and I prefer to listen to my music this way for the most part anyway.

Thanks to anyone who can clarify any of these things for me. The clock is a bit of a mystery to me. I might not even need it at all if it’s not improving the sound when playing back via the SPDIF input.

An external Clock only makes sense if you need to synchronise numerous digital sources simultaneously, and synchronise them to a ‘Master’. This is one of the reasons that external clocks have multiple Wordclock outputs.

It makes no sense at all when using it for just a single item, such as a CD player etc. In this scenario, the player’s inbuilt clock will more than suffice.

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The Rossini clock is only useful for the following sources

Internal streamer board (Roon, Mosaic, Airplay etc)
USB input

Not for AES, S/PDIF and the like as these sources carry their own embedded clock signal, and using any other clock source than Audio will eventually cause hiccups. Now if your external source has a wordclock INPUT then the Rossini Clock could come into play again: connect output 3 to the source and let the source use the Rossini clock, then set Rossini to Auto Wordclock and things will sync up - this would be the ideal way to connect an external source.

The two extra buttons on the clock are for “dithering” - you can do a search for that term on this forum and you’ll find an expert explanation on the subject straight from the horses’ mouth.

From some people’s favorite home spun guru, the non-necessity of clocks -

And from his guru -

Couple of things…

A high quality clock is important - whether external or internal. The issue is not so much femto-second precision but a stable clock without audible frequency drifts. If you have a clock where the frequency drifts up and down say 1000 times a second (much more slowly than the clock itself), that will introduce jitter bands in a signal. So if your input signal is say a 5KHz sine wave, you will see bands at 4KHz and 6KHz.

A clock that is thermally stable, with a low noise power supply, mechanically isolated so no vibrations percolate into the clock signal will be better. This is what the external clock is doing for you.

If your CD transport was able to use an input clock (like all dCS transports do) then you would synchronize the whole chain (transport and DAC) with one signal. This is the design in the entire dCS ecosystem - the master clock syncs transport, upsampler (Vivaldi case) and DAC.

If your CD transport cannot take a clock input, strictly speaking your DAC needs to sync to the clock recovered from the SPDIF signal (either coax or AES) and is thus slaved to the possible jitter in the transport clock - in this case the external clock is useless.

You can set the Rossini to use the master clock even with SPDIF, but you run the risk of glitches in the sound. Enable the buffer in the Rossini in this case.

You mention getting noise from the clock. I have not ever once experienced that, and I use my Rossini DAC with the Rossini clock always, for like 5 years now. Your Rossini clock must have an issue.

Depends… If you use a transport that can take a clock input - all dCS, some CEC, possibly others - then your external clock can sync the whole chain, completely avoiding the major ill of the SPDIF design.

Additionally, you can run the Rossini forcing it to use the clock for timing. The risk you run is that it will play until a level transition crosses the boundary between two cycles and you could get a glitch in the sound at that point. So it “sounds better” until it glitches. I tried this for a while with a cheapo Cambridge CXC transport and never had a glitch. I think the combination of the buffer (which is small) and the proximity of the clock speeds meant it never in practice bumped into that issue. But it could.

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Is the clock in your Rossini DAC is so bad that it drifts enough over short periods of time to be an issue? If it does, and you need an external clock, Rossini should be ashamed of themselves for using less precise clocks.

It’s a matter of degree, a matter of how good the rest of your system is, and a matter of how good a listener you are.

Many people argue that cables don’t make a difference. Maybe it is their system is not resolving enough, or THEY cannot hear a difference, or a combination.

Actually Ted Smith explains the importance of phase stability which is the same as low frequency drift.

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A good clock is not going to drift enough to be a problem over the short term. We don’t care about the clock being accurate over long periods of time. It needs to be accurate over very short periods of time.

I don’t see how how phase stability is the same as specifically low frequency drift.

Read this:

and this:

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Pretty sure I heard him say, in the last sentence in the vid, that he’d never use a rubidium clock.

This comment is beneath your usual contributions.

Phase in frequency space is the same as time shift in the time domain. Look into Fourier transforms.

Rubidium, correct. A clock with low phase noise, he says this throughout the video. Phase is the same as time drift.

Actually, I truly believe people not hearing cable differences are either not as discerning or the system is not resolving enough. I am not sure how to say this more precisely.

I do admit my comment was a little aggressive.

Do you mean digital cables?

The implication is that whenever someone disagrees about whether something has an effect, it’s because of poorer ears or poorer system than one who does hear an effect

It is a trope that is too easily invoked, like “the ways of god are mysterious”.

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That is not the implication. I have over and over again heard differences with cables, and so have other people I regard as having great expertise in matters of audio. The implication is really that one needs to learn to distinguish such differences and that these differences are subtle and require a good enough system to be perceived.

I cannot tell the difference in my interconnects between a Sonos port and an Adcom amp playing over cheap speakers but can easily tell them apart on my main rig.

Some people cannot tell the difference between DACs above $1000 - most of my non-audiophile friends can’t. But I think we can agree that there are such differences.

Would you say that someone who cannot tell the difference between a run of the mill pinot noir and a benchmark red burgundy has the right to say they are the same? I don’t make any judgements about them, but you can’t tell me there’s a version of the universe where the difference is not real.

You said “low frequency drift”. Maybe you meant “frequency drift”…

That would have to include those “Parkers” with golden palettes claiming that they can tell the difference. Subjective appreciation by all the senses is equally unreliable.

This one is 10 years old now but the issue has long been a running sore in fine wine appreciation circles as it is in audiophile circles.

In an infinite meta-verse, there’s an infinity of possibilities. :slightly_smiling_face: