replace ceramic resonator with quartz crystal in cheaper CD players

[wa2ise]

How "not" critical? I'm planning to replace such resonator last night (too late at night that I decided to sleep). The frequency is 20MHz. I think I have plenty of crystals with this frequency. What would be the effect of the upgrade? Can it affect sound quality? What if I use 16.9MHz? or 25MHz? Or 40MHz?

It shouldn't have any impact on sound quality. It's just controlling the speed of the microcontroller, which usually is just used to scan keypads for button presses, opening and closing the CD drawer, and such tasks. I wouldn't deviate much from the orginal frequency, as that might cause problems with the drawer opener motor and such. In any event, avoid getting too close to the master system clock frequency, as you might get some undesired audio beat notes getting into the sound.

I don't see any real reason to change that microcontroller resonator anyway.

 

[Jay]

(16.9344-16.25)/16.9344 x 100%= 4% slower

And how slow is 4%? I guess tube amp is 2% slower than solid state, so it's twice as slow. I got the idea
😉

 

[Jay]

It shouldn't have any impact on sound quality. It's just controlling the speed of the microcontroller, which usually is just used to scan keypads for button presses, opening and closing the CD drawer, and such tasks. I wouldn't deviate much from the orginal frequency, as that might cause problems with the drawer opener motor and such. In any event, avoid getting too close to the master system clock frequency, as you might get some undesired audio beat notes getting into the sound.

I don't see any real reason to change that microcontroller resonator anyway.

Hmm... I won't change it unless I see 20MHz crystal right in front of my eyes. Who knows, the track reading will be faster 😉

 

[davidsrsb]

If you're referring to the "balls", those ones are different from the beads on the leads. Anyhow, I have been questioning the function of these beads as well. From your explanation, their function is not critical IMO, not enough justification to use fancy beads like that.

Are you talking about the 3 terminal filter device which are basically a ceramic capacitor to ground and two ferrite beads threaded onto the leads giving a T section low pass filter

How come? How the lead can help here?

Lead free solder has a much higher melting point so the risk of damage to the component is greater

 

[Jay]

Are you talking about the 3 terminal filter device which are basically a ceramic capacitor to ground

That's what I was talking about in my first post. I just not sure what it was. It's like ceramic capacitor with 2 balls. It has 3 legs with the mid leg grounded.

a ceramic capacitor to ground and two ferrite beads threaded onto the leads giving a T section low pass filter

I think I haven't seen something like that. What I seen is another ball probably from ceramics, not ferrite, used on the legs of silver mica capacitors, diodes, etc.

Lead free solder has a much higher melting point so the risk of damage to the component is greater

Hmmm... I see. I use 40W, and it is quite fast for both of them. But yes, the one with Pb is faster. I have been using silver tin for a long time, and when I tried "Sellery" tin a few days ago, oh, I knew I've missed that Pb smell.

 

[ash_dac]

I have been using silver tin for a long time, and when I tried "Sellery" tin a few days ago, oh, I knew I've missed that Pb smell.

If you keep that up you will get to a point where the forum posts cease to have any meaning.

Please stay off the Pb!

My cd723 has a ceramic resonator, and needs replacing!


Regards,

Ashley.

 

[davidsrsb]

Metallic lead is not that toxic, unlike the organic lead compounds once used in petrol. The only real risk to hobbyists is the solder dust residue inside solder pumps, which is too easy to get onto your skin and ingest.

I have seen streams in the Welsh mountains near the old gold mineswith metal salt crystals forming in them. That water must be toxic.