Re: Re: Clock power supply
KK Hos power supply.
On this site?:
http://www.kk-electronic.dk/default.aspx?l2=3&action=page
Who, what is KK Hos???
fmak said:
KK Hos power supply.
On this site?:
http://www.kk-electronic.dk/default.aspx?l2=3&action=page
Who, what is KK Hos???
Re: Re: Re: Clock power supply
Search in Trading Post. K K Ho is an electronics engineer in Hong Kong.
------------------------------------------------------------------Elso Kwak said:
KK Hos power supply.
On this site?:
http://www.kk-electronic.dk/default.aspx?l2=3&action=page
Who, what is KK Hos???
Search in Trading Post. K K Ho is an electronics engineer in Hong Kong.
Re: Re: Re: Re: Clock power supply
Fred M.,
Now this is interresting as I tried to find KK Ho using the forums searchengine. Negative, nada, zip.
Then I tried worldwide Google and found it in one millisecond!:http://www.diyaudio.com/forums/showthread.php?threadid=25777
Not much information what is on Ho's PCB or clock though.
fmak said:
Fred M.,
Now this is interresting as I tried to find KK Ho using the forums searchengine. Negative, nada, zip.
Then I tried worldwide Google and found it in one millisecond!:http://www.diyaudio.com/forums/showthread.php?threadid=25777
Not much information what is on Ho's PCB or clock though.
Re: How noisy
Hi Fred,
Yes I know. You can even add additional RC sections effectively increasing the order of the filter. I believe the noise of the transistor becomes the limiting factor. It was all in this link:
http://www3.sympatico.ca/add.automation/spice/ripple.htm
But it is dead for some time.
Whether a follower or "something else" is best for a clock circuit remains to be seen.
Fred Dieckmann said:
Hi Fred,
Yes I know. You can even add additional RC sections effectively increasing the order of the filter. I believe the noise of the transistor becomes the limiting factor. It was all in this link:
http://www3.sympatico.ca/add.automation/spice/ripple.htm
But it is dead for some time.
Whether a follower or "something else" is best for a clock circuit remains to be seen.
Re: Re: Re: Re: Re: Clock power supply
If you buy from him, he will let you have circuit.
-----------------------------------------------------------------Elso Kwak said:
Fred M.,
Now this is interresting as I tried to find KK Ho using the forums searchengine. Negative, nada, zip.
Then I tried worldwide Google and found it in one millisecond!:http://www.diyaudio.com/forums/showthread.php?threadid=25777
Not much information what is on Ho's PCB or clock though.
If you buy from him, he will let you have circuit.
Re: Paging Mr. K.K. Ho
Do a post in Trading Post about TCXO by K K Ho and ask for his email. I am not sure he wants his email disclosed in public.
----------------------------------------------------------------------Elso Kwak said:
Fmak,
An emailaddress or website referring to Mr. Ho would be helpful. I can't find any more information about his clock and powersupply.
Thanks in advance.
Do a post in Trading Post about TCXO by K K Ho and ask for his email. I am not sure he wants his email disclosed in public.
Re: fmax measures
Hi Pedro,
I always advise using the raw digital supply of the player. Meaning connecting the clock at he bridge rectifier or the main filter caps of the digital supply.
Some emails I received confirm this is the best approach, sonically.
Of course clock mongers do want to sell an extra supply with transformer. Or YMMV!
Also I tried recently again a preregulator like the LM317 with bypassed adjustment pin and the result (sonically), was worse than without preregulator.
But again YMMV.
pedro said:
Hi Pedro,
I always advise using the raw digital supply of the player. Meaning connecting the clock at he bridge rectifier or the main filter caps of the digital supply.
Some emails I received confirm this is the best approach, sonically.
Of course clock mongers do want to sell an extra supply with transformer. Or YMMV!
Also I tried recently again a preregulator like the LM317 with bypassed adjustment pin and the result (sonically), was worse than without preregulator.
But again YMMV.
Re: schematics
That's what I call a short circuit ! Please have a closer look at the PCB and you'll see what I mean. Pins 8 and 4 ( 5V and GND ) are shorted. The layout in post 11 was better except for the location of the 47 uF OSCON.
I advise a separate supply/transformer with any clock to avoid ground loops. When a separate supply is used there simply can't be a loop because you only connect ground at the ground of the cdplayers pcb ( at just one point ).
When an internal supply is used there is a possibility that the ground via the clock board will be a lower impedance "bypass" of the ground path of the cdplayer ( as experienced by me with various Philips cdplayers ). That can have nasty side effects like hearing the drawer/tray motor over your speakers, intermediate humm/noise that's hard to trace etc. Besides that the clock can cause stray RF that causes the supply to become "dirty". Measurements confirmed this. I don't comment on sonical differences. A ground loop is a ground loop, add the RF to it and that's enough for me. I did not like the 3-wire technique ( sharing the output and power ground over 1 wire ) as used by some clock manufacturers although it does not have the disadvantage of a ground loop.
When a separate supply is not possible please only use the raw digital supply as suggested. The analog and servo supplies have a hard time already... Take your time and make a drawing of how you want to wire the new clock. Ground is again the keyword here. Shielding of the clock is not a luxury and using shielded cable is a pre. Some turns of the output coax through a ferrite core avoids RF to wander across the shield of your cables.
pedro said:
That's what I call a short circuit ! Please have a closer look at the PCB and you'll see what I mean. Pins 8 and 4 ( 5V and GND ) are shorted. The layout in post 11 was better except for the location of the 47 uF OSCON.
I advise a separate supply/transformer with any clock to avoid ground loops. When a separate supply is used there simply can't be a loop because you only connect ground at the ground of the cdplayers pcb ( at just one point ).
When an internal supply is used there is a possibility that the ground via the clock board will be a lower impedance "bypass" of the ground path of the cdplayer ( as experienced by me with various Philips cdplayers ). That can have nasty side effects like hearing the drawer/tray motor over your speakers, intermediate humm/noise that's hard to trace etc. Besides that the clock can cause stray RF that causes the supply to become "dirty". Measurements confirmed this. I don't comment on sonical differences. A ground loop is a ground loop, add the RF to it and that's enough for me. I did not like the 3-wire technique ( sharing the output and power ground over 1 wire ) as used by some clock manufacturers although it does not have the disadvantage of a ground loop.
When a separate supply is not possible please only use the raw digital supply as suggested. The analog and servo supplies have a hard time already... Take your time and make a drawing of how you want to wire the new clock. Ground is again the keyword here. Shielding of the clock is not a luxury and using shielded cable is a pre. Some turns of the output coax through a ferrite core avoids RF to wander across the shield of your cables.
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