Kwak clock not working - pls advise

[Assyst1606]

Guys...thank u very much.
After connecting the COM of the external power supply to the GND of my CDP, the Kwak clock works.
Next is to build a power supply unit for the Kwak clock. Have this circuit in mind -


Feel free to comment & feedback.

[Extreme_Boky]

The power supply noise performance will determine the amount of clock oscillator jitter (together with the PCB design) - therefore use Jung regulators:

http://www.aoselectronics.com/jungsrpcb.html

The clock oscillator ground should be connected to the CD player ground at the point where the CD player (digital) ground noise is minimal. What you really want to achieve here is the minimal clock oscillator ground noise level. This depends on clock oscillator power supply noise AS WELL AS which ground point you choose in your CD player.

Connecting clock oscillator power supply ground with CD player ground will reference the external oscillator frequency (and the CD player will start to work properly), but this is not optimal solution.

Good luck

Boky

[poynton]

Originally posted by Extreme_Boky
The power supply noise performance will determine the amount of clock oscillator jitter (together with the PCB design) - therefore use Jung regulators:

Don't forget the Quack clock has its own "internal" regulators already.

The supply as outlined is perfectly adequate to provide the +/- 12v supply.


Andy

[Extreme_Boky]

it will provide + and - 12 V, but it is far from being good PS

[Richard]

Hi Extreme Boky,

The clock oscillator ground should be connected to the CD player ground at the point where the CD player (digital) ground noise is minimal. What you really want to achieve here is the minimal clock oscillator ground noise level. This depends on clock oscillator power supply noise AS WELL AS which ground point you choose in your CD player.

I was wondering if you could you please suggest how one would find the lowest (digital ground) noise point in a CD player.

I just finished building a power supply for a kwak clock and wanted to optimise its connections.

Richard

[Richard]

Hi Assyst1606,

Extreme Boky is correct in regard to low noise power supplies for the Kwak Clock, but as Andy points out the Kwak Clock already has TL431 shunt regulators.

I ended up building a (pre-regulator) power supply for my Kwak clock that is very similar to the one you posted. However, I used a transformer with dual secondaries and built it with a 4 diode bridge for each (+/- 12V) rail, keeping the grounds for each rail seperate, only joining them at the clock itself. In addition, I also used a common mode choke (CMC) (Epcos 39mH) after the 1st filter cap. On a scope the CMC reduced noise level by about half. The clock only uses about 10mA so I used 78L12 & 79L12 100mA regulators to keep it all small.

For the diodes try BYV26C, BYV27-200 or 11DQ10.

In regard to C5 & C6 NPO or COG (ceramic) caps are fine, Elso also suggests silver mica. As for a pic see below.

Cheers,

Richard

[Assyst1606]

Hi Richard,
Thanks for the reply & the info. I’m not good in my electronics, is it possible u could post the schematic & photo of your power supply? I got the transformer from my workplace workshop & I intend to use it for the Kwak clock power supply.
I have other questions –
1) Will there be a great improvement if I replace the original crystal (from the CDP that is currently on the Kwak clock) with a better one? If yes, what brand & spec should I be looking for (other than to be of the same frequency)?
2) Lastly I saw some articles mentioning about removing the muting caps on the output RCA. Are these caps connected across the RCA output? I heard u can hear popping sound when switching the CDP ON/OFF if u remove the muting caps, is that true? Will that cause any damage to the amp or speakers?

[Richard]

Hi Assyst1606,

I don’t think there will be a great improvement with an upgraded crystal in the Kwal clock. I did try this in a Marantz Cd 63 and did not notice any difference. As the learned guys have suggested in previous posts, your clock layout is spread over a rather large area, you will benefit by wiring it on a smaller board with the components closer together.

However, Pedja reports differnces in the crystal with the Kwak asynchronous reclocker, but thats another story.(http://www.pedjarogic.com/1541a/rev1.htm).

Have a look at the website below, there is a version of the Kwak clock that runs on a single +5V supply and is rather compact.
http://home.quicknet.nl/qn/prive/ra..../index_en.html
see under DIY projects “Clock PCB”

As for the muting caps removal, I’m not really sure as I have not tried it, but there is some advice on lampizator.eu. See snip it and bypass:
http://www.lampizator.eu/SNIPIT/lampizator_DIY.html

Finally when I get some time I’ll draw out a schematic of the psu I used, but It is pretty much identical to yours.
Hope all that helps

Cheers,

Richard

[Assyst1606]

Thanks for the comment.
I don't quite understand the single 5V supply Kwak clock version. There are 2 output (pin 7 & 8).
Anyway i don't think i'll be building one unless i have another CD player. The current one seems good, more detail, less harsh & improve bass extension.

[fossil2k]

Hi guys. I'm interested to build a KWAK clock for my CD63 but do not have the schematic. Can anyone of you guys be kind enough to email me a copy?