Add a dedicate clock generator stage on tube CD

[luca56]

Hi ,

I like to add a dedicate clock stage on my Jolida JD100 CD player.

here some photos:

http://www.pro-software.it/photo1.jpg
http://www.pro-software.it/photo2.jpg
http://www.pro-software.it/photo3.jpg
http://www.pro-software.it/photo7.jpg

The clock that I like to take in cosideration is:

1PPM 16.9344 8.4672 Mhz Low Jitter TCXO Clock Module - eBay (item 270624899051 end time Sep-19-10 20:58:24 PDT)

My questions are:

1) This clock stage is better then my actual circuit ?

2) If Yes, there are some sound quality difference ?

[Bill Fuss]

It should be better, only one way to find out.

[luca56]

Hi Bill ,

Thanks for your reply !!!! I don't have any experience about clock stage upgrade.

Do you have try similar operations ?

I see on the market there are clock circuits at 150/200$ or more ...

For your opinion what are the factors (apart the price) that I must see before purchase ?

[poynton]

Bill is correct .. If it sounds better, then it is better.

From a more technical viewpoint, whether it is "better" depends on the clock implementation in the CDP.

It looks like it uses a crystal and logic gates to form the oscillator. This is a basic type.

The proposed replacement uses a crystal oscillator module with its own power supply. This should be more stable and provide better isolation from the rest of the circuitry.

Having said that, you could fit the module and end up with a worse sound due to a bad installation.

As far as price is concerned, it's usually a case of diminishing returns.


Andy


.

[jean-paul]

Luca56, the clock PCB you pointed at is not a good choice as it focuses on some less important features. A deviation of 1 ppm is nice but what you need is a low jitter clock with a low noise power supply. You can try to build a DIY Kwak clock or use Guido Tents modules for good results. The first one is a fully discrete DIY design which is not expensive to build, the second one is a reasonable priced high quality low jitter clock module that needs a good power supply.

If I remember correctly I still have an unused/new Tent 16.9344 MHz module in my stock. If you can use that one you could send me a PM.

[luca56]

Excuse me, another important question:

As you can see on the pictures my CD Player have 2 separate transformers:

One for the digital and another for analog.

Teorically I must add another transformer for the clock stage.

What happen If I use one of the actual transformer without add a new ?

[Bill Fuss]

It will always be better to power it with it's own trafo if you can squeeze one in. If you can't, you can steal some raw DC from either trafo you have and pre-regulate it for the clock board. You might be limited by what voltage you have available to work with though.

Without test equipment you can't determine how good the XO module is that is supplied with the kit, but it can be replaced with an excellent Tent XO module at a later date. I have tried to get phase noise graphs from these Chinese suppliers but they have no interest in supplying useful info.

I can tell you that a good clock improves many aspects of the sonics, if your system has the resolution to reproduce it.

[luca56]

I'am very happy to write to expert people !!!

I don't have a good experience on audio upgrade.

Apart the clock stage I like to do other mods on my cd:

in attach (zip file) the details.

I like to undestand if these mods are good.

What you think about clock upgrade + this mods ??

[Guido Tent]

Originally Posted by luca56

Hi ,

I like to add a dedicate clock stage on my Jolida JD100 CD player.

here some photos:

http://www.pro-software.it/photo1.jpg
http://www.pro-software.it/photo2.jpg
http://www.pro-software.it/photo3.jpg
http://www.pro-software.it/photo7.jpg

The clock that I like to take in cosideration is:

1PPM 16.9344 8.4672 Mhz Low Jitter TCXO Clock Module - eBay (item 270624899051 end time Sep-19-10 20:58:24 PDT)

My questions are:

1) This clock stage is better then my actual circuit ?

2) If Yes, there are some sound quality difference ?

It is -125dBc at 1 kHz. My clocks are-150dBC there....

http://www.tentlabs.com/Components/X...XO_33.8688.jpg

best

Guido

[luca56]

There is a large difference with and without dedicate PSU ?