kwak-clock connection

KWAK CLOCK connection

Hi Nick,
The crystal(XD01) and the two small caps connected to it (CD02 & CD03 ) should be removed from the CDP. The crystal can be used in the KWAK-CLOCK.
The ouput of the KWAK-CLOCK should be connected to one of the PCB solderpads of the original crystal. According to LCAudio it is the pad closest to the rear panel.
Also you have to find +/- 5V and ground.:)
 
basically i just need to follow the instructions provided in the lc audio website

i think i will use an external ps for +- 5 volts
very familar with 78 and 79 construction
the cd63 ps isn't very good
using a better supply gives better reference when comparing signals in comparator rite plus this is used for the crystal rite?

the ferrite bead inductor which type can i used?
any special type i need to use.

10 M resistor is slightly hard to source
but there is a special film resistor for this value
tolerance is 0.02 %
but the price is usd16 per piece
is the 10 M resistor very crucial or can i just go with 1% tolerance

i plan to use silver mica for the critical caps

can i test the circuit on the oscillope

elso thanx for the file
 
KWAK-CLOCK Connection

Hi Nick and Rudolf,
Thanks Rudolf, this one escaped my attention.
The ferrite bead is just a small bead in the powersupply lead. Not very important.
Tolerance on the 10M resistor is not important 5% perfectly OK even 1M will probably work or as Rudolf says several in series.
NPO ceramics(zero tempco) work as well as silvered mica and are much cheaper.
You can test the circuit on the scope but don't expect to see a square wave. It is more like a distorted sine wave. If you make a probe with a 50 Ohm coaxial cable and set the scope at 50 Ohm input impedance or connecting a 50 resistor to ground, then you will see a nice square wave if your scope has adequate bandwith.
 
i was talking to someone about the clock
he recommended a few things
noise from a comparator will enter the ground
to avoid this he recommended to install 0.001 uf decoupling caps across the legs of the comparator ( + and - legs).

and the other thing he mention that the cap to use after the comparator 10 nf can be polystrene. High frequency thru the cap

and finally the resistor after the 10 nf cap (47 ohm) needs to be non- metallic or non-inductive or else it might disturb the output waveform. he recommended to try a few resistors here
he mention that the 47 ohm resistor is very important and the type choosed must be tweak under the scope

elso he aslo talk about using polystrene for the pf range you used in the clock, he feels that polystrene is better there. he doesn't feel that silver mica is good for audio.

also learn some new things on handling jfets from him,
when handling the jfets wrap a wire around the legs of the jfet
this is to short out and prevent esd. he caution me by saying that by blowing at the jfet is enough impedance to spoilt the jfet
very scary. I have not handle mosfet or jfet before so this is quite new to me. Anyone know whats is the proper static control so that i can implement

some advise i wish to pass on to other constructors after learning some new stuff today
 
Mods to the KWAK-CLOCK

Hi NickC,
Feel free to experiment with different caps, powersupply bypassing or other series resistors.
I once installed my clock in a SonyCDPXA30ES and the CDP only wanted to work with a 3.3µH inductor in series with the clock output. Later I tried this in my own CDP and worked as well. <B>NO</B> difference in sound!
I have my doubts about poystyrene caps for a 16.9344 MHz clock but give it a try and post your results. I have even seen clockPCB's with large polypropylene caps in the output that apparently worked satisfactory.
Finally a JFET is not as sensitive as a MOSFET to static.;)
 
The LC website do not have instructions for the NAD C541. I have the downloaded the datasheet of the C541's DAC (BB PCM1732), according to the datasheet, the clock out from the Kwak Clock should be connected to pin 5 (Xin) of the DAC. So I removed the 16.9334 crystal and the two capacitors to disable the built in clock. Next I connected the gnd of the Kwak clock to the gnd of the 7805 voltage regulator and the +5V to the bypass cap of the regulator (I have measured the voltage and confirmed that it is 5V). The clock out (with a 1k resistor) is then connected to the pin 5 of the DAC (one of the pin of the original crystal is connected to pin 5).
Power on the CDP and it was able to detect the CD (so the clock must be working and the connections should be correct). Removed the 1k resistor and mounted the clock to the CDP PCB using blue tac. Power on again, it took a few tries before the CDP can detect the CD. There's also some squiching noise mixed with the output from the CDP. It lasted for awhile and the noise just goes away and everything was working fine. Tested for 5 min and confirmed that it was working. Adjusted the Kwak Clock to make sure that it was secured to the CDP PCB and placed back the cover. Power on the CDP again to test. This time it was unable to detect any CD. It just keep giving me "NO CD detected" message.
Anybody knows what went wrong?
 

binatang

Member
2002-06-04 7:02 am
Icceman:

Nice to see you here. A small world indeed :)

Have you tried connecting the +5V directly to the output of the 7805. I've connect my clock to the output of the 7805 whereas the clock out & ground are connected directly to the old clock circuit on the PCB.

I've recently also installed a kwak clock with its own 7805 voltage regulator with a 1k resistor biasing output to ground. In this instance I connected the +v to the ps cap before the CDP's 7805. There was a noticeable improvemnt in sound (in my system) with the clock using its own voltage regulator.
 
Kwak-Clock Connection

Hi iceman,
I am sorry to hear that the implementation is not succesfull.
You can try a few things:
1) Try a 3.3µH choke in series with the clock output.
2) Connect a 1M bleeder resistor from the clock output to ground.
3) Play with ground connections; connect ground at the regulator or at one of the pads of the small caps connected to the original crystal.
Hope this helps.:)
 
Does it work intermmitently? Or does it always work?

It works everytime without failure. I think u have to be careful with the Jfet and IC (I've learn it the hard way).
There are 5 voltage regulator in the C541, 2 (7805 and 7808, I think they're for the transport), 2 for the opamps (analog stage, LM317 & LM337) and 1 (7805) for the DAC. All the regulators are bypassed by 1000uF Cerafine cap. The Kwak Clock draws it's power from the regulator that is powering the DAC (I have replaced the 7805 to LT1086 and bypassed it with a 1000uF Os-Con cap).

Below are the installation instructions for NAD C541 owners:

1). Remove the 16.9344Mhz crystal and the 2 capacitors
next to it (C328 and C329) to disable the built in
clock.

2). Connect the the gnd of the Kwak Clock to the
gnd (pin 2) of the 7805 that is next to the DAC.

3). Connect the +5V of the Kwak Clock to the
bypass cap (positive wire of the 1000uF Cerafine) that is connected to the output (pin 3) of the 7805.

4). Connect the clock out of the Kwak Clock to the
pin 5 (Xtin) of the DAC (the crystal solder pad that is next to C329).

I would like to say thank you to Elso for the clock schematic and Binatang for helping me in installing the clock.:)
 
Does it work intermmitently? Or does it always work?

It works everytime without failure. I think u have to be careful with the Jfet and IC.
There are 5 voltage regulator in the C541, 2 (7805 and 7808, I think they're for the transport), 2 for the opamps (analog stage, LM317 & LM337) and 1 (7805) for the DAC. All the regulators are bypassed by 1000uF Cerafine cap. The Kwak Clock draws it's power from the regulator that is powering the DAC (I have replaced the 7805 to LT1086 and bypassed it with a 1000uF Os-Con cap).

Below are the installation instructions for NAD C541 owners:

1). Remove the 16.9344Mhz crystal and the 2 capacitors
next to it (C328 and C329) to disable the built in
clock.

2). Connect the the gnd of the Kwak Clock to the
gnd (pin 2) of the 7805 that is next to the DAC.

3). Connect the +5V of the Kwak Clock to the
bypass cap (positive wire of the 1000uF Cerafine) that is connected to the output (pin 3) of the 7805.

4). Connect the clock out of the Kwak Clock to the
pin 5 (Xtin) of the DAC (the crystal solder pad that is next to C329).

I would like to say thank you to Elso for the clock schematic and Binatang for helping me in installing the clock.