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-   -   what kind of capacitors is connected to the CD player's crystal? (http://www.diyaudio.com/forums/digital-source/3404-what-kind-capacitors-connected-cd-players-crystal.html)

jarthel 3rd May 2002 04:05 PM

what kind of capacitors is connected to the CD player's crystal?
 
as title. Thank you. :)

jayel

peranders 3rd May 2002 04:58 PM

Do you mean what type or why?

Type: probely ceramic of some sort, NP0 maybe

Why: To create suitable load in order to get stable oscillations

Value: (>5)15-33 pF is normal values

If you change the value you can tune the frequency but you get a worse ocsillator. It's wise to tune as little as possible.

jarthel 3rd May 2002 05:36 PM

I had a looked in Farnell's catalog.

I don't see NPO ceramics. I can only see ceramic multilayer/disc & palte.

I also had a look at RS online catalog and they don't have NPO ceramic.

Can you please clarify? Thank you. :)

Jayel

tiroth 3rd May 2002 06:23 PM

NP0 (or C0G) is the dielectric, not the physical makup (multilayer/monolithic, etc)

If it is Z5U/X7R/etc it isn't NP0.

peranders 3rd May 2002 07:23 PM

May I ask why you wonder about these caps?

fmak 3rd May 2002 08:03 PM

Quote:

Originally posted by jarthel
I had a looked in Farnell's catalog.

I don't see NPO ceramics. I can only see ceramic multilayer/disc & palte.

I also had a look at RS online catalog and they don't have NPO ceramic.

Can you please clarify? Thank you. :)

Jayel

---------------------------------------------------

Look again at Farnell hard copy. They have moulded ones but are expensive. They also have cheaper dipped ones and COGs

jarthel 5th May 2002 03:38 PM

Quote:

Originally posted by peranders
May I ask why you wonder about these caps?
Cause I think I might have broke these caps during modding. :-)

jackinnj 5th May 2002 05:51 PM

If you need to in a pinch
 
you can always take two insulated wires, twist together (like a twisted pair) - one inch or less - connect in parallel across the crystal, and make a capacitor for the crystal oscillator. I used to do this to "tweak" the frequency of a crystal by changing the capacitance.

Jocko Homo 5th May 2002 05:53 PM

That's only good for a few pF. The values he will need a are more likely in the 10-30 pF range.

Jocko

sonnya 5th May 2002 06:50 PM

Do not change it to X7R, Y5U or anything else than COG or NPO. Anything else to unstable regarding capacitance versus temperature.

Go for the the Values specified by Jocko or PerAnders.

Sonny


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