Three things you can do to make CD players sound better

[Jocko Homo]

This for guys who really are interested in learning. If you want to argue pointless theoretical crap, there are other threads. Don't say I didn't warn you.

Three things I guarantee will improve your sound. Won't cost much,and you will probably learn something new if you try, instead of just sit around and whine.

Here goes:

1.) Put a low(er) jitter clock in your player. Lots of people sell them. Elso has posted schematics, I have posted schematics. Try one. Try all of them. Any are better than stock. Lower jitter simply translates into better sound. (Maybe I will 'splain why later.)

2.) Get rid of the feedback loop after the DAC. Doesn't matter if it is R-2R I-out, or delta-sigma. You do not need an op-amp with feedback to perform this simple, low-level (in tems of signal) function.

The big boys do that because op-amps are cheap by the millions. And they use less space. This is DIY, we don't have those limitations.

May require using the old noggin to come up with something good. Which means you will have better sound, along with more knowledge.

3.) Fix the ground loop problems. You would be amazed if you look closely enough how bad the grounding is in a lot (but not all) CD players. They use autorouters to design this stuff, and to them, ground is ground, just like DC is DC, and bits is bits.

But we know better. True, you may need an audio spectrum analyzer to really do this, but a lot of you guys seem knowledgable in using sound cards, and software to use them for measurements.

And while you are at it........look at the rails when a disc is spinning. Probably the only thing that 1 kHz square wave you guys worry so much about is good for.

How do I know this? I have designed, built, measured, and listened to enough of this stuff, long enough to know this.

Rather than sit around and whine like some of you seem to enjoy doing.

So, try these ideas. You don't have to thank me, just try them.

Jocko

[halojoy]

I will do the 3 points tomorrow.
This will be good.

[UrSv]

1.)
I will try this one. Have been planning it a long time.

2.)
I will try this one. Have been planning it a long time.

3.)
I would not know how to use the "audio rectal paralyzer" to do this one. It will have to wait unless I find something really bad and run it coarse ground.

And BTW, thanks for the suggestions. ;0)

/UrSv

PS. Just for sports I will also replace my tinky E-core 12 VA based all 78xx/79xx PSU to match as the new clock will need a nice welcome. Maybe it it will help, maybe it won't. I trust it will.

[Jocko Homo]

Part of the trick to making the low-noise oscillator thingie work is to get rid of all the noise on the rail. 78xx series may not be a good choice, except as a pre-regulator.

Jocko

[Elso Kwak]

Hi All,
Please see my post on AA. Also three points but two different from Jocko's.
http://db.audioasylum.com/cgi/m.pl?f...k&r=&session=;)
No hard feelings Jocko, just <B>my</B> opinion/experience.

[UrSv]

Originally posted by Jocko Homo
78xx series may not be a good choice, except as a pre-regulator.

Jocko

Exactly my thought. That is why I said I would replace it. It will probably be something like LT108X regs to start.

/UrSv

[PhopsonNY]

1./ Have done it...great

3./ Have done some...great

The question is #2... don't quite have the electronic smarts to decode this...

Is this referring to the I/V concerter with feedback loop...I doubt it.

[jwb]

Originally posted by Jocko Homo
Part of the trick to making the low-noise oscillator thingie work is to get rid of all the noise on the rail. 78xx series may not be a good choice, except as a pre-regulator.

Prevailing custom amongst the locals is to use LT1085, but the regulator isn't going to attenuate noise in the MHz range. Combine a good regulator with ferrite bead filtering and thoughtful PCB layout.

I think the fourth element missing in this list is making the rails quieter. By improving the decoupling, regulation, and filtering of the supply lines you can reduce noise throughout the player.

[Fred Dieckmann]

"currently I am using a 48 MHz crystal in the third overtone mode, as the reclocker clock and it sounds fine. (Schematic also available by sending etc.)"

Don't leave us in suspense Mr. Kwak!

Conspiring minds want to know,
Fred

[halojoy]

how can you hear third overtones?
I have a lot of trouble to try to catch the second overtone