Master Clock Generators

[Andybrown163]

Hi All

Has anybody and practical experience with Master Clock Generators? I have read reviews of the Esoteric G-0Rb that say it can have a marked affect on system performance. Are there any alternatives? Does anybody own one of these? Where I could get a demo?

Thanks for your interest

Andy

[pluto]

In the studio world, a master clock (or rather, a master reference) is a normal part of the furniture. The reason for it has nothing to do with sound quality, but rather the requirement that sources can be readily mixed together; everything needs to be running in sync. In a domestic context, any kit you use has to be capable of running on an external clock feed. Furthermore, the clock has to have a means of adjusting according to sampling rate of the material you are playing - the very concept of a master clock implies that the sampling rate does not like being changed.

In the Esoteric part number you mention, I assume that "Rb" means Rubidium - the basis of a highly accurate oscillator. While I'm sure the unit in question is very good, there is nothing to be gained by having a clock accurate to 1 part in 10,000,000,000. That kind of accuracy is necessary when you need a 3 hour long picture reel and its related sound reel to remain frame-accurate when the two are driven by different clock sources. Long term accuracy bears no relation to the ultra short term accuracy (jitter) over which audiophiles obsess. A rubidium source does not, in and of itself, say anything about jitter performance.

Where am I going with this? A true master clock is probably complete overkill (and potentially inconvenient) in a typical domestic set up. A possibly better solution is to use a good DAC (in which money has been spent on a decent clock) which has a clock output available for distribution to other pieces of equipment. But this is entirely unnecessary if the DAC is fed via asynchronous USB, as this method of feeding a signal into a DAC offers the stability of a master clock without any of the ensuing inconvenience.

[Andybrown163]

Hi Pluto. Thanks for your feedback which I have read with much interest. The following is an extract from a review of the G0Rb used with a Esoteric D03/P03 combo which has prompted my question.

"The idea of an atomic clock sitting in your equipment rack to make digital sound more like analog appears bizarre on the surface, but one listen to the G-0Rb will convince you that such a precise timing reference is a fundamental requirement of state-of-the-art digital playback." full review:- http://www.avguide.com/review/tas-18...nerator?page=1

I found this most intriguing. My K-03 has a pretty decent DAC built in and my system performance is superb. Despite claims of mains cables being "snake oil" on installing an Aluminata mains cable onto my K-03 and decent support the performance took a quantum leap improvement. No doubts! Master clocks???

[sq225917]

If you think expensive mains cables make a real and beneficial difference then this sort of stuff is designed just for people like you. A better clock inside the dac might be worthwhile, but in reality, secondary and tertiary effects are likely to be far more audible that absolute clock accuracy.

[Andybrown163]

I am guessing you are not speaking from experience Simon. I know mains cables make a hugh difference but IMO the difference is in relation to the quality of equipment one has. I am not interested in a debate as I already have an answer to this one. I am interested to hear from anybody with experience of master clocks!

[meninblack]

[chris217]

I am guessing you are not speaking from experience Simon. I know mains cables make a hugh difference but IMO the difference is in relation to the quality of equipment one has. I am not interested in a debate as I already have an answer to this one. I am interested to hear from anybody with experience of master clocks!

This is the technical section. Please justify your currently unsubstantiated claims.

[earlofsodbury]

I have on loan from Keith at Purité a full set of M2Tech's little silver "Evo" range of digital boxes - DAC, interface, battery PSU and clock generator.

I own a Hiface2 and wanted to see if the upgrade was worth the candle, so Keith suggested I try all the associated kit and see what works for me...

I started with the interface, and it did indeed sound subjectively better - simply more resolution, then I added DAC and PSU and those too worked well, the battery PSU surprising me a bit at how much it improved the sound...

I nearly didn't bother with the clock as I couldn't see what it could bring to the party, especially as it could only (and rather absurdly) work with the interface unit and not the DAC!

Obligation and idle curiosity got the better of me though, so as a token effort I lashed it on - and there too was another small subjective improvement to overall resolution. I was frankly surprised by this.

Why this is I'm not sure, but I was convinced enough of the difference to buy all four units as the basis for a computer-based system!

YMMV!

churz, sod

[meninblack]

Moved to 2-channel as the OP is clearly after some justification to blow £10k on a clock rather than a technical discussion.

IMO a better DAC (ie one NOT made by Esoteric) is a more worthwhile upgrade.

[Cable Monkey]

I work with Rubidium clocks at the apex of a synchronisation distribution system that feeds a number of other timing sources. It is to help ensure a significant number of assorted network assets work ok together without issue. Looking at the matter from that point of view, that provides the structure that a studio might require. It stands to reason that if you wanted to remove yourself from the studio environment but still listen at that same level of accuracy then a clock of similar accuracy would be the ideal scenario. Where I start to lose the plot a little is where this level of accuracy is used for CD because stable Rubidium clocks are not cheap and require a significant amount of environmental management to keep them reliable (in the mission critical environment I work in).
To answer the OP, it is a lot of expense and effort to go to and you might be better off with a DAC you prefer rather than wringing additional performance out of your existing DAC.

[sq225917]

I am guessing you are not speaking from experience Simon. I know mains cables make a hugh difference but IMO the difference is in relation to the quality of equipment one has. I am not interested in a debate as I already have an answer to this one. I am interested to hear from anybody with experience of master clocks!

Yes you are correct, mains cables can only make a difference with incompetently designed kit...

[Andybrown163]

This is the technical section. Please justify your currently unsubstantiated claims.

Hi Chris

Apologies if I have posted this in the wrong section. I am new to forums as you may be able to tell.

Regarding my comments to Simon, through my hung over haze I did find his comments a little disparaging - In retrospect I apologise for any offence I may have caused.

My reference to mains cables is based on my own subjective experience. I went to a dealer and auditioned mains cables on the same set-up i have. It made an unbelievable difference. I was astonished. I have noticed in other threads If anybody dares to assert this datum then they are in for a hard time.

With regards to master clocks - having spoken to an Esoteric dealer regarding Master Clocks his opinion was that they make only a very small difference. The review I referred to earlier in the thread, the writer absolutely raves over the difference it can make stating technical reasons for the difference. Due to these opposing views, I am interested to know what you guys think and how differences in imagining and detail of the magnitude indicated could come about.

Regards
Andy

[Andybrown163]

Moved to 2-channel as the OP is clearly after some justification to blow £10k on a clock rather than a technical discussion.

IMO a better DAC (ie one NOT made by Esoteric) is a more worthwhile upgrade.

My current system is an upgrade and I am very pleased with it. I don't think my wife would stand for another £10K

[Samantha]

If you think your kit would benefit, it would be a lot less costly to try the M2Tech version. Not sure of the price, but it is £00s rather than £000s

[AmDismal]

I know that the thread has been moved, but technically, the best place for the clock is as close to the decoder as possible. If you have lots of stuff to sync, you would use a device that took a clock in from the DAC, then shared this out with the rest of the kit. I think that early dCS clocks worked like this.

[pluto]

Hi Pluto. Thanks for your feedback which I have read with much interest

Reading back my earlier post, I realise that, thanks to a day of alcohol abuse, I didn’t make my basic point well enough.

Master clocks serve two unrelated purposes –

• The creation of a clock signal to be distributed around multiple items of kit in a studio installation.
• The provision of a higher quality clock signal than the kit itself is capable of making.

I think it’s fair to say that the former isn’t relevant to a typical domestic installation especially now that asynchronous inputs (via USB & Firewire) are becoming commonplace. So there remains the question of clock quality. This falls into two parts – long term and short term accuracy. The former is completely irrelevant in your home. It matters not whether your Gotterdammerung runs for 4h 37m 43.5s or 4h 37m 44.2s. Short term accuracy relates to the precise pacing of each clock cycle and one of the problems with a clock generator is that, regardless how good that clock unit may be, its signal has to be fed to the external equipment and, ultimately, to the converter chip within the black box that you call a ‘DAC’.

Most of the harm is likely to be done after the clock signal has entered your DAC and becomes subject to whatever noise, electromagnetic pollution or sheer bad design it encounters; all the brilliance and expense of the super-clock counts for nothing. Most DAC designers will tell you that you are better off with the devil you know. In short, buy a DAC which has had no (reasonable) expense spared on its own internal clock.

If a DAC – any DAC – is audibly improved by the provision of an external clock, it is apparent that the designer has not invested as much on the internal clock as he ought. While a good external clock may be an undoubted improvement over a poor internal clock, you’d be much better off with a decent internal clock to start with.

[meninblack]

If you think your kit would benefit, it would be a lot less costly to try the M2Tech version. Not sure of the price, but it is £00s rather than £000s

One note of caution - there doesn't seem to be a standard for clocks. My Victor DAC has a clock output that would synchronize beautifully with the Victor transport, but my current dCS transport doesn't recognise it at all and won't lock.

[Samantha]

Makes sense - benefits of buying new though would be to try with existing kit.

Wouldn't be top of my shopping list so my knowledge is limited :thumbup:

[nat8808]

Hi Pluto. Thanks for your feedback which I have read with much interest. The following is an extract from a review of the G0Rb used with a Esoteric D03/P03 combo which has prompted my question.

"The idea of an atomic clock sitting in your equipment rack to make digital sound more like analog appears bizarre on the surface, but one listen to the G-0Rb will convince you that such a precise timing reference is a fundamental requirement of state-of-the-art digital playback." full review:- http://www.avguide.com/review/tas-18...nerator?page=1

I found this most intriguing. My K-03 has a pretty decent DAC built in and my system performance is superb. Despite claims of mains cables being "snake oil" on installing an Aluminata mains cable onto my K-03 and decent support the performance took a quantum leap improvement. No doubts! Master clocks???

That copy, written by the marketing department, is no more informative or enticing (to me) than a rep saying 'you should hear our new kit, it's really really good!'

[nat8808]

There's a Sound on Sound article about master clocks in the studio - their tests concluded that sound quality was worse or the same when using one compared to the internal clock. They sited technical reasons for this too. It was for ADCs rather than DACs but A->D is much harder to do so will show up differences more.

http://www.soundonsound.com/sos/jun1...sterclocks.htm

A sumary:

There’s a widespread notion that adding a high-quality master clock to a digital system will somehow magically improve its overall performance. While that might possibly have been the case in the very early days of semi-pro digital converters where, frankly, some of the internal digital clock designs were pretty ropey, it certainly isn’t the case today. As I’ve explained above — and will prove below — today’s converter designs generally work best on their own internal clocks, and most will deliver a slightly poorer performance when clocked externally. The very best devices will show no change in performance at all, because they have superb clock-extraction circuitry that can remove all traces of clock jitter and other external clocking artifacts, so they work just as well as when running on their internal clock.
So, although sonic differences may be perceived when using an external clock as compared to running on an internal clock, and those differences may even seem quite pleasant in some situations, this is entirely due to added intermodulation distortions and other clock-recovery related artifacts rather than any real audio benefits, as the test plots illustrate.

....

The obvious conclusion is that in simple digital audio setups a master clock is usually unnecessary, although it remains critical that multiple digital devices are clocked sensibly. In more elaborate digital audio systems, a master clock can make the task of slaving multiple units much easier and neater, and allow the system to operate more reliably. In systems where digital audio is being used in synchronism with video, an appropriate master clock is absolutely essential. But in any of these cases, the use of a master clock will not improve the audio quality achieved by the converters in any technical sense — and the most expensive clocks fare no better in this regard than the least expensive. The only relevant criteria for purchase is whether the clock provides the facilities, inputs and outputs required, and is designed sufficiently well to conform with AES11 Grade 1 standard.

One of the clocks on test was the Antelope Audio Isochrone Trinity with 10M rubidium atomic clock - a total RRP of £8k.. yet didn't improve sound quality in their opinion.

Check out the box at the end of the article too about the importance of correct digital cabling and how it can effect sound quality.