LClock Schematics

[ALW]

They are very good for audio (Vishay MMA0204 series) These are the best SMD resistors for low 3rd harmonic distortion available. And low noise too ...

Lars,

Did you mean BC Components (Beyschlag) instead of Vishay?

Interesting comment though - have you personally measured these and what else you you compared them with?

Regards,

Andy.

 

[jwb]

Elso, Guido, next thing for you are series resonance oscillators, not so hard to design but the trouble is to get crystals, 99.999% of all crystals are for parallel mode. But.... it's not very expensive to order special crystals.

The crystals are specified for parallel mode, but any crystal can operate in either mode. The question is, at what frequency will it oscillate in series mode? It will be slightly different from the parallel frequency. If you need an exact frequency, that would be a problem but for our purposes it shouldn't matter.

 

[Jocko Homo]

You know that........and I know that.....

And I get tired of repeating it.

I suggest that both of "you guys" measure the frequency repsonse of a crystal some time.

It is obvious that neither of you ever have. You are talking apples and oranges with your constant confusion over crystal terminology vs oscillator tank terminology.

End of rant.

Jocko

 

[carlosfm]

Out of topic, sorry...

Lars, can you repply to the mail I've sent you?
Thanks.

 

[jwb]

In case we're still having trouble with the series/parallel concept, here's impedance vs. frequency for a typical crystal. Fs is the series point, Fa is the anti-resonant (parallel) point. When you add capacitors in the oscillator, the crystal operates somewhere between Fs and Fa.

 

[Lars Clausen]

AWB

 

[ALW]

Lars

You got me there

Are you using the 10ppm precision parts or the 50ppm standard parts (I could open the CD player an look at the XO3 in there, I suppose) ?

Interesting though, will have to investigate those in more detail - thanks.

Andy.

 

[Lars Clausen]

Carlosfm: i have been looking for a mail from you, but did not see any yet .. Please send again.... thanks!

 

[Lars Clausen]

ALW: Normally i would use the 50 ppm parts, they are by far stable enough for my purposes.

However the ones on the picture are 0.1% 10ppm parts, because i had them in the drawer for another application.

 

[Jocko Homo]

This is how you measure a crystal....

And its series resonance.

 

[Jocko Homo]

And if you want to measure a "parallel" crystal.....

The setup changes to this:

 

[carlosfm]

ALW: Normally i would use the 50 ppm parts, they are by far stable enough for my purposes.

However the ones on the picture are 0.1% 10ppm parts, because i had them in the drawer for another application.

Lars, my old and beautiful original LC-Audio XO clock has a 5ppm crystal.
Now you use 50ppm?
Doesn't it make a difference?

 

[peranders]

Lars, my old and beautiful original LC-Audio XO clock has a 5ppm crystal.
Now you use 50ppm?
Doesn't it make a difference?

Hardly if we talk change in key. The important thing is a stable frequency. You must also count in aging and temp drift, rather many ppm.

 

[Bricolo]

Where can we admire the XO3's schematic?

 

[Audiofanatic]

When?

Where can we admire the XO3's schematic?

Audiofanatic

 

[carlosfm]

Someone had to ask...

Where can we admire the XO3's schematic?

 

[Audiofanatic]

Can you read minds?

Audiofanatic

 

[Lars Clausen]

Carlosfm: In that post i was talking about MMA0204 resistors in amplifier design, NOT crystals.

Since you asked the question about my company's product, i will reply, that we still use 5 ppm. XTAL's in LClock XO3, but they are adjusted to 1 ppm, so the important spec is not really the initial accuracy, but rather the temperature coecifient. Here the spec is 10 ppm 10-50C.

You others: I am working on some other development work right now, taking all my time. So as i said, it may take a couple of weeks before i can post the schematics of XO3 as well.

 

[Lars Clausen]

Here is the Schematic of LClock XO / XO2 from year 2000.

 

[Lars Clausen]

And here in a ZIP file with better resolution: