| LC CLOCK for 33.8688MHz or above - Click HERE for Original Thread |
| nFORCE |
Hi all,
Who know how to make it?
Please give me some hints.
Thanks alot
nFORCE |
|
|
| alfsch |
Hi,
at these frequ you need overtone-mode osz, the most simple to start and (for me) as a reference is a gate-osz; later you can build another, like a colpitts type and hear, wether you can improve quality...
here is my circuit: works at 33,x MHz
alf |
|
|
| Wombat |
@nForce
When you build the clock of alfsch - be sure to use this 74VHC
type of Hex-Inverter.
I changed my 74HCU04 to this 74VHC04 and sound improves quite
a bit!
I have a 49,15MHz clock in my Sony DAC. |
|
|
| nFORCE |
Dear Sir,
At your old post, I found that
"If your need a higher frequency for example 33 MHz for DVD you will need a overtone circuit, that I also can provide"
Could you mind give me some hints of 33.8688 and 45.1584MHz?
Merry X'mas
Regards,
nFORCE |
|
|
| Elso Kwak |
| quote: | Originally posted by nFORCE
Dear Sir,
At your old post, I found that
"If your need a higher frequency for example 33 MHz for DVD you will need a overtone circuit, that I also can provide"
Could you mind give me some hints of 33.8688 and 45.1584MHz?
Merry X'mas
Regards,
nFORCE |
Hi nFORCE,
I am sorry that information is obsolete.
A <B>fundamental</B> mode 33.8688 MHz and 45.1584 MHz crystal will work in the regular KWAK-CLOCK.
See also:
http://www.diyaudio.com/forums/show...ight=optimising
The post: "Low Jitter Crystal"
;)
Merry Christmas too:xmastree: |
|
|
| HpW |
>> VHC04
Keep in mind that the xxxxU04 must be used for oscillattors !
See also related VHCU04 on Fairchild :
Since the internal circuit is composed of a single stage inverter, it can be used in analog applications such as crystal oscillators. An input protection circuit ensures that 0V to 7V can be applied to the input pins without regard to the supply voltage. This device can be used to interface 5V to 3V systems and two supply systems such as battery backup. This circuit prevents device destruction due to mismatched supply and input voltages.
and see the VHC pdf file with the gain curve of VHCU04 and the alike level trigger threshold behavior for VHC04!
www.fairchildsemi.com/pf/74/74VHC04.html
www.fairchildsemi.com/pf/74/74VHCU04.html
VHC general : http://www.fairchildsemi.com/ms/MS/MS-521.pdf
Cheers
Hp. Widmer |
|
|
| Wombat |
Well,
all i can say - when using the 74VHC without "U" i can here the more rlaxed and cleaner
sound (most mids) against the 74HCU without "V". Don´t know how the 74VHCU is sounding.
The fairchild pdf says about the 74VHC without "U"
"The internal circuit is composed of 3 stages including buffer output, which provide high
noise immunity and stable output...."
Maybe this counts also!? |
|
|
| HpW |
Did you ground the crystal box ? Use also smd caps for the oscillator and block the IC with additional 0.1uF smd cap's!
While overtone is not a very easy task in case not haveing related measurement instruments to measure the phase noise!
Cheers
Hp. Widmer |
|
|
| Wombat |
It is an existing clock in a Sony SDP90 sound processor DAC.
All i have done is changing the Hex-Inverter.
I can post the shematic later. |
|
|
| Wombat |
| Thats it, not more, not less. |
|
|
| hill |
Elso,
I'm very interest in the KWAK-CLOCK which you had mentioned.
Could u send me a copy of schematics ?
Thanks in advance.
my mail address: aax_man@hotmail.com |
|
|
| Wombat |
When we are at it.
Did anybody do some testing of the 74VHC against the 74VHCU?
Another thing:
Has anybody successfully build a good 49.152MHz clock?
I even can´t find as place that sells these crystals here :( |
|
|
|
|
