clock upgrade for cd/dvd players

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These clock upgrades are quite popular, and there is definitely some merit to reducing the jitter produced by the ****-poor clocks typically found in consumer gear. However, I would never spend an absurd 175 pounds on one!

As a DIYer, I would at least attempt something on my own. There is an excellent book on crystal oscillators (though you may experience the same difficulty locating it as i have): Crystal Oscillator Circuits by Robert J. Matthys, ISBN 0471874019.

Since finding this book, I've been toying with the Meacham bridge circuit, which appears to be the best of the lot. Perhaps some more modern circuits would outperform it, I don't know. Anyhow, I've only managed a few initial prototypes, and havn't yet been able to measure the jitter...

Anyone know how to measure jitter without expensive equipment???

Anyway, if you don't want to try building your own oscillator from scratch, you can buy a canned oscillator. Valpey-Fischer supplies very low jitter clocks. Add a good power regulator and a decent buffer chip, and bingo! ...you've got yourself a module just as good as this expensive kit.
 
oh yeah, of course you void your warranty if you go ahead and install one of these, and you'll also need to know where to tap the power for your clock, and where to remove the stock crystal and insert yours. Finally, you'll also want to verify that you're supplying the correct logic levels to the chip... these days, a lot of consumer equipment is using 3.3V ICs.
 
Clock upgrades

I've no experience of clock upgrades to a DVD player, but did fit one into a Marantz CD63 KI Sig and it was a truly huge massive improvement.

Another colleague fitted one to an old Meridian CDP and the results were just as good.

Jitter is one of the most fundamental issues to tackle in digital audio, it doesn't just decrease resolution, but generates non-musical spurious signals that are particularly horrid to the ear (i.e. they have no correlation to the audio signal).

Some manufacturers have stated that jitter of just 1-2 psec is audible.

I used a clock from Danish company LCAudio, which is considerably cheaper than the Audiocom or Trichord products, whilst offering almost identical performance.

There is a new version out called LClock XO2 (I used the LClock XO in the Marantz) that is a little more expensive but it's worth every single penny in my book.

A colleague is about to try one of these in an entry-level Naim CDP, the results will be interesting!

Andy.
 
Re: Re: other diy-clock

cinglong said:
weeghel said:
http://ariel.club.tip.nl/

Please check out this page, andlook for the cd player upgrade. Contact Guido Tent to ask for prices on the pcb boards he has just developed for this XO-Clock


Is this website broken recently??
I cannot connect it this week

Just checked it, worked fine. Don't use http://www.ariel... just ariel.club.tip.nl
 
My DAC/Transport XCLOCK Experience

hifi said:
47E ?? what the hell is that???....shouldnt it be 47R as in 47 ohms? (check the diy clock schematic)

/micke

I have checked out http://ariel.club.tip.nl/ and it is online. I contacted Mr. Guido via EMAIL. He is very helpful and confirmed that 47E is indeed 47 Ohms. I just ordered an oscillator from him. I will report the result when I finish installing it on a Philips CD player (used as transport) and a California Audio Gamma DAC.

T.K.



Update:

I have built the XCLOCK circuit using Mr. Guido's Oscillator($29 including shipping) and some resistors, capacitors, a ferrite and a choke. He does have an assembled PCB for about $105 and a DAC version for $130. I would use the finished product except that it may not fit into my cramped DAC and also I enjoy building things myself.

I assembled and put the XCLOCK in my DAC (a California Audio Gamma DAC), diabled the clock in the transport (a Philips CDF-200 photo CD player) and connect the DAC XCLOCK output back to the transport. It was quite some work. It took me a few days (off and on) planning and ordering parts and 5 nights making it. The amounts of work in building the PCB and in connecting it into the DAC and Transport are approximately the same. This may not have been typical. The philips trasporst PCB is very hard to get to. The California Audio Gamma DAC has limited space inside. The installation of the PCB into DAC/Transport would be much easier otherwise.

Now the result:

The sound is nothing short of phenomenal. The sound is clearer. You can hear individual instruments much better. The music sounds more musical also. I can hear so much more details that just was not there before. The piano sounds like it is right in your living room. It was well worth the effort. It will probably cost me about $1000 if I want to buy a new DAC to achieve the same result. Unfortunately, this may end my venture into DIY, since I am very happy with the sound of my system now.

A note of caution. You do need a decent pre/power amp to get the benefit. I am using a Jolida 502A modified to run Triode mode, all signal path capacitors replaced with oil caps, negative feed back disconnected and power supply capacitor bypassed with a 2UF oil cap. I used some Russian military surplus oil caps which were claimed to be paper oil. Judging from the physical sizes, they may have been foil polyporpylene caps. I do not have a personal preference between Tube and Semiconductor but Tube is a little easier for DIY and more schematics are available. The modifications to the Jolida is very important. I was not very happy with the sound with the unmodified Jolida. There are other ways to modify the Jolida, but I picked the easiest way. It took me only half a day and the result was extremely rewarding.

I hope my experience will help you on your future DIY projects.

P.S. I apologize that I forgot to mention that I was able to make the modification since both my DAC and Transport are using 11,2896 MHz clock. If you can get an old Philips CD player for cheap, it would be a good transport.

If you have a 11,2896 MHz DAC and a 16,9344 MHz transport, you may be able to use a 33,8688 MHz clock with a 1/2 and 1/3 clock divider circuits. I am not a EE major and do not know how to design the dividers. I searched the internet and did not find any schematics that I could readily use.

Mr. Guido sells an assembled DAC XOClock unit for $130. I do not know if it works with dissimilar DAC/Transport rates. You may want to email and ask him.
 
hmm.. this lookslike a standard canned oscillator. You can buy one with the same specs for about $5. (same risetime, frequency tolerance). Or, you can get a better one from Valpey-Fisher (faster risetime -> less jitter). Also, there is an error in the schematics: there should not be any capacitor on the output from the oscillator. For best jitter performance, clock symmetry and to keep from damaging the other chip, this 10nF cap should be removed!
 
Hi:

I am very intrest to try on this too. But I have something dont understand how to do it.

Ok! Actrally I have the CDP which using the Philps transpot and the clock is 16.9344MHz. I've installed the Lclock XO2 on it already!

And my DAC is the CS8412+PMD100+PCM1702K. I found that the artcle which in their site said CS8412 provide the clock is something like 11.XXXMHZ.....

Then what should I do if I like to connect in one clock?
Which frequency should I using on it??

Thanks!
 
XO oscillators

dear all,

After reading some of your comments and experiences, I felt it is time to elleborate a little on my XO. It started all with designing a DAC, and being confronted with jitter of recovered clocks.

http://members.chello.nl/~m.heijligers/DAChtml/dactop.htm

After being able to measure on jitter (I have access to a wavecrest Time Domain Analyser, of which only 2 pieces are ever sold in the Netherlands), understanding what I measured, and correlating it to the sonical texture, I went searching for stand alone oscillators. After lots of samples came in, I started a mega test.
ALL of them measure and sound different. only 2 where found to be acceptable, both from sonical point of view, as well as the measurement. I continued with one manufacturer, and was able to even improve the oscillator he used to make.
With respect to risetime: Higher risetimes do not yield lower jitter specs by definition, on the contrary it might get worse (as more RF charge displacement takes place in and out of the silicon, the groundbounce messes up the performance - this is also a reason why I advise a series resistor of 47 ohm, as such the current is limitted somewhat).
I decided to offer both separate oscillator as well as ready made products with a very low noise power supply, al with 5 years warrantee.
If you have specific questions you may Email me.

all the best

Guido
 
hi guido!

i heavily modified my player:
4 power supplies dual stage regulation each.
removed transistorizied mute & emphasis (replcd w relays)
regulated power servo section (fok/trk/spdl/trv)
replaced optical pickup wires
burr brown op amps and some more!
the only thing original is the brand on the faceplate!!

i made a clock reshape with a 74hc00 from the word clock
coming from the dsp to the dac .
it performs a lot lot better but in my socpe i still see small jitter that i want to remove???

the clock is a 33.8688 meg that feeds the dac, dac divides f by 2
& the feeds the dsp.

i am interested to install a master clock?

do i have to reshape the clock that goes to the dsp from dac?

it is worth to reshape all signals from dsp to dac or just only the word clock

word clock/bit clock/lr clock/data? what signal you consider more critical?? (i mada a reshape to l/r clock & it went almost out ou phase due to delay!

any info will be appreciated or exchanged with more info about
mcintosh mc 275 heavy mods or my player

merry christmas
richt
 
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