Jitter the killer of digital audio

seafire

Ok with my somewhat heated entry onto this forum I thought I could post a genuine contribution for all serious audiophiles.I had the privilege to hear this product in action during a recent visit to Germany.The before and after results are nothing short of astounding and many will for the first time realize what the problem with cd has been all along.The only way to describe it is..think of your best sounding vinyl and now imagine this with no surface scratches and even more dynamics and extension.No.1 on my list of future have to gets
seafire;)
link: www.jitter.de
Also check out this guy's other machines under ALtmann Micro Machines

heiney9

Jitter is a real issue not to be taken lightly. That's one of the differences between a good DAC and a great DAC.

The link you posted while old (as in seen it before a while ago and posted it myself here several years ago) is still a good explanation. I wouldn't buy any of his products......a Monarchy DIP (digital interphase processor) is a great little unit you put between a transport and an outboard dac to reduce clock induced jitter. There are many kinds of jitter with clock induced being the most damaging, (ie; most audible) IMHO.

H9

tonyb

Not like it's the first time we discussed jitter,but I agree,overlooked often.

Flash21

Just an odd thought, probably way off base, but - would jitter in any way explain how different digital interconnects can sound different? In other words, can jitter be introduced during transmission of a digital signal?

heiney9

seafire wrote: »

The only way to describe it is..think of your best sounding vinyl and now imagine this with no surface scratches and even more dynamics and extension.No.1 on my list of future have to gets
seafire;)
link: www.jitter.de
Also check out this guy's other machines under ALtmann Micro Machines

That's not at all how I would describe it. It's more of a hard edge or "glare" added to the music.....a type of distortion that can grate on you and cause listening fatigue if it's severe.

Changes are subtle at best, but they are there none the less when using higher end digital gear with excellent jitter chracteristics.

seafire

H9 just out of interest why wouldn't you buy any of his products? I take it that you have found cheaper alternatives.All I can say is what I heard blew me away and I was there on business so havent bought the units yet;)

seafire

Flash21 wrote: »

Just an odd thought, probably way off base, but - would jitter in any way explain how different digital interconnects can sound different? In other words, can jitter be introduced during transmission of a digital signal?

Yes absolutely correct;)

heiney9

Flash21 wrote: »

Just an odd thought, probably way off base, but - would jitter in any way explain how different digital interconnects can sound different? In other words, can jitter be introduced during transmission of a digital signal?

That's a highly debatable portion of the jitter issue. Can't say one way or the other.

Clock induced jitter is the most common and most noticable to the ear and the most easily corrected by way of better built A/D D/A conversion circuits or by use of an outboard re-clocking unit like the Monarchy.

H9

P.s. I'm out of this one as it is another highly charged debate among audio enthusiasts. Seafire is batting 1000 if he's trying to stir things up.

seafire

heiney9 wrote: »

That's not at all how I would describe it. It's more of a hard edge or "glare" added to the music.....a type of distortion that can grate on you and cause listening fatigue if it's severe.

Changes are subtle at best, but they are there none the less when using higher end digital gear with excellent jitter chracteristics.

On what I heard changes were subtle on high end external Dacs but still audible.But what blew me away were the changes it made to hi end and middle class Cd players :eek:

seafire

heiney9 wrote: »

That's a highly debatable portion of the jitter issue. Can't say one way or the other.

Clock induced jitter is the most common and most noticable to the ear and the most easily corrected by way of better built A/D D/A conversion circuits or by use of an outboard re-clocking unit like the Monarchy.

H9

P.s. I'm out of this one as it is another highly charged debate among audio enthusiasts. Seafire is batting 1000 if he's trying to stir things up.

H9 please believe I am not trying to stir and if it is a highly debated subject I will withdraw right now

Systems

Flash21 wrote: »

In other words, can jitter be introduced during transmission of a digital signal?

Absolutely.Transmiting the digital data via the SPDIF interface (coax/toslink)does introduce jitter because the clock and data signals get combined and transmitted together on a single conductor instead of individually.Timing errors occur when the input reciever chip of the DAC unit has to separate the clock and data signals at the recieving end.

Flash21

Well I am just fishing for an easy explanation, I guess you are saying there isn't an easy explanation...

I went to the link like a good little Polkster and found references to "line-induced jitter", although the explanation wasn't very satisfying.

...transmission of a digital signal... will add jitter to our signal whether we use a coaxial cable TOSLINK or SToptical interfaces.

Funny enough, all these interfaces behave different and add different kinds of jitter (different in jitter amplitude, waveform, frequency distribution, correlation).

So now you have the answer to the following questions:

* Why do different digital interfaces sound different, although they carry exactly the same information?
* Why do different cable lenghts sound different?
* Why do some coaxial cables of the same lenght but different manufacturers sound different?

This is line induced jitter.

Guess I'll have to look into this a little more carefully. I'm not all that worried about it, I don't currently have any digital interconnects in my system. But someday I expect I will have a music server hooked to my Cambridge 840C...

heiney9

Ok, you I do agree that jitter is an issue that is overlooked and there are ways to reduce it and it can be heard.

I have experience with the Monarchy unit. It's not that I wouldn't buy his.....I'd need to do more research about his product. Reducing jitter is no small task and to be honest looking at his product it looks a little to simpleton to me.

seafire

I speak under correction but from what I understand you are correct in saying clock based jitter is the biggest problem.Followed by noise induced jitter like noisy power supplies and ac supply line noise.Then from what I understand you have jitter introduced at any point where the signal changes medium.They say that even the cd motor noise and vibration contribute to jitter AGAIN I SPEAK UNDER CORRECTION and stand to be corrected;)

seafire

Where can I read up about the Monarchy unit?

Systems

seafire wrote: »

I speak under correction but from what I understand you are correct in saying clock based jitter is the biggest problem.

All jitter is clock based as it is the result of timing errors.

seafire

GV#27 wrote: »

Absolutely.Transmiting the digital data via the SPDIF interface (coax/toslink)does introduce jitter because the clock and data signals get combined and transmitted together on a single conductor instead of individually.Timing errors occur when the input reciever chip of the DAC unit has to separate the clock and data signals at the recieving end.

Hmm I'm also learning as we go along;)All I can say is that I have heard these units and am purchasing before year end.For H9 I think they have dealers in the States..maybe worth a follow up and give it an audition and come back with your thoughts:)

ben62670

Jitter is why I prefer coax over toslink. Two less conversions is two less areas that can throw timing off.

Systems

seafire wrote: »

Where can I read up about the Monarchy unit?

IMO the best type of add on jitter reduction is one that uses a sample rate converter IC or ASRC.

steveinaz

Cable reflection error in digital coax's can also be a source of cable-induced jitter. From what I have read, use a well-specified 75ohm cable, at least 1mtr in length to reduce this effect.

Stereophile did a very interesting study on cable-induced jitter; they found that cheap coaxial cables (cheap as in construction) were actually "directional" in that plugging the cable one way would show very high levels of jitter, but switching the cable around would reduce it significantly--interesting. Better quality cables didn't benefit from swapping direction, but their jitter specs were good from the start. They had no explanation and were dumbfounded by the finding.

seafire

GV#27 wrote: »

All jitter is clock based as it is the result of timing errors.

Right I think I get you.Although they are introduced at various points and because of various reasons the end result always relates to the master clock timing being out of synch..Am I getting it???

seafire

ben62670 wrote: »

Jitter is why I prefer coax over toslink. Two less conversions is two less areas that can throw timing off.

Makes sense;)

steveinaz

Think of jitter as an unfocused camera; because of timing errors the signal is smeared, so to speak.

Systems

seafire wrote: »

Right I think I get you.Although they are introduced at various points and because of various reasons the end result always relates to the master clock timing being out of synch..Am I getting it???

Put simply Yes.

steveinaz

ben62670 wrote: »

Jitter is why I prefer coax over toslink. Two less conversions is two less areas that can throw timing off.

There is another camp of thought that says because Toslink cannot suffer from cable reflections, it's immune to cable-induced jitter. Is this beneficial? hell I don't know, I'm a dumb warehouse guy.

Systems

steveinaz wrote: »

There is another camp of thought that says because Toslink cannot suffer from cable reflections, it's immune to cable-induced jitter.

But both can suffer from the shortcomings of the SP/DIF transmitter /reciever inferface.

seafire

steveinaz wrote: »

There is another camp of thought that says because Toslink cannot suffer from cable reflections, it's immune to cable-induced jitter. Is this beneficial? hell I don't know, I'm a dumb warehouse guy.

Ok but remember that it goes through two extra conversions and so is exposed to more jitter as Ben pointed out

steveinaz

True. Is the extra conversion a factor? I don't know...

seafire

Years back I read a article on tweaking cd players in this case a Sony cdp 990 .I ordered a higher quality power supply from Rs electronics and also re mounted this far away from the Dacs.I then proceeded in applying Blu tack to every mountable place on the cd drive and added a copper plate between the power supply and the rest.The Player sounded much better and today I realize I must have improved the jitter.I still use Blu tack on all my cd players and computer drives and I swear it makes a difference
I dont know what it's called in the US but its the stuff we use to stick posters to the wall:)

Systems

Im betting the difference was the power supply:)

steveinaz

me two's.