Hi all as any one tried this clock just wondered if there any good as i need one for my marrantz 67 Good for CD player Active Clock Plate 16.9344MHZ on eBay (end time 09-Apr-11 16:17:38 BST)
I'm far from an expert, but from reading on the topic, what I took away from reading is that its the smoothness of the power supply that supplies the clock, which is one of the biggest factors in the quality and accuracy of the clock. Simply using a 1PPM TCXO crystal is not going to give you better sound. Look at this clock and see how there is a big effort to use various capacitors and inductors to give a smooth power supply EZ Ultimate Clock System | Diy HiFi Supply and it includes its own dedicated transformer power supply as well!
Having said that I a while ago tried a different but a little better designed cheap clock upgrade kit from ebay, and at the time I thought it made a difference, but better or just different, I was never sure, any improvement was probably placebo effect.
Perhaps you are better to use some better power supply capacitors that supply the existing clock in your player?
Others may have an opinion?
Having said that I a while ago tried a different but a little better designed cheap clock upgrade kit from ebay, and at the time I thought it made a difference, but better or just different, I was never sure, any improvement was probably placebo effect.
Perhaps you are better to use some better power supply capacitors that supply the existing clock in your player?
Others may have an opinion?
Last edited:
I just wonder how you know you need a clock? Bolting on an external clock like this might not lead to lower jitter because with an externally wired clock you've got common impedances in the ground wires - the clock isn't differential. With the supply current going through the ground wire as well as the ground being used as signal reference there's noise coupling into the clock signal. Shorter wires are the solution but that's impossible with such an after-market mod. If higher jitter is the result, no doubt the placebo effect will more than compensate for this 
I agree with you erin - power supplies to clocks are crucial.
I agree with you erin - power supplies to clocks are crucial.
Hi thanks for replys i did read some were that the power supply for the clock is very important.Reason i thought about a clock in the player is because in the marrantz cd 63 and 67 mods list it says its one the important upgrades to do the player already has biger better quality caps upgraded opamps and another exsternal power supply
Hi andy would you not bother with that clock then. Can you recomend another cheap one if this is not any good. thanks steve
Hi,
The only spec that is important for the clock in a CD player is short term stability. Crystal oscillators happen to be very good in this regard. Therefore, about the only thing I can think of that might mess things up is a noisy power supply. If the supply is a mess, then build a crystal oscillator and use a buffer to drive the clock input of the IC and this is the best things will get.
You can also purchase clocks for the CD player that are discipled by the GPS satellite network. Overkill, but perfect for the audiophile braggart.
Remember, the only important specs are jitter and short term stability. These two terms overlap somewhat. Anything else is a waste of money. Don't buy cheap crystals!
-Chris
The only spec that is important for the clock in a CD player is short term stability. Crystal oscillators happen to be very good in this regard. Therefore, about the only thing I can think of that might mess things up is a noisy power supply. If the supply is a mess, then build a crystal oscillator and use a buffer to drive the clock input of the IC and this is the best things will get.
You can also purchase clocks for the CD player that are discipled by the GPS satellite network. Overkill, but perfect for the audiophile braggart.
Remember, the only important specs are jitter and short term stability. These two terms overlap somewhat. Anything else is a waste of money. Don't buy cheap crystals!
-Chris
Hi chris thanks for reply im fairly new to the diy hifi game and dont want to spend too much money on a clock as i dont have much confidence in my work yet
Hi bull041161,
Sounds good.
All you need to do is use common sense. Ask questions and do good, clean work. I'd advise against doing anything you can't come back from (permanent changes).
Most of high end tweaks are grabs for your money, except when a real fault or short coming is being addressed. Just pay attention to the basics of how things work. Also, a CD player is not a turntable. Belt drive and "stable platter" offerings are stupid. A CD must be able to change rotational speed quickly. It ain't a turntable!
-Chris
Sounds good.
All you need to do is use common sense. Ask questions and do good, clean work. I'd advise against doing anything you can't come back from (permanent changes).
Most of high end tweaks are grabs for your money, except when a real fault or short coming is being addressed. Just pay attention to the basics of how things work. Also, a CD player is not a turntable. Belt drive and "stable platter" offerings are stupid. A CD must be able to change rotational speed quickly. It ain't a turntable!
-Chris
Hi chris yes i agree im not going to tackle any thing too difficult. I have done the hdam by pass uprated some caps but i have just added some those fantastic screned ha op amps and thay made a real big improvement in sound
This one is "better" as it does have built-in regulation.
But it is more expensive.!!
Andy
.
It's not very difficult to build a decent power supply. The entire point of DIY is to be able to avoid excessive expenses for simple devices.
Hi dtses, Andy,
That one isn't very expensive considering you get a good PCB - stuffed and ready to go. Shock mount it and you might really have something.
I have a problem with some well known people's assemblies that cost a great deal more that may be about the same performance, or even less.
Now, the real question is, what is actually going to be helpful to jitter performance in a meaningful way? How easily can that be implemented? The "kit" in the last link may be required to tame a cheap CD player. But then the question begs to be asked - why? A cheap and nasty CD player will have far more serious problems than simply jitter! Why bother in that case?
So, as an exercise, why not define what characteristics are really needed to reduce a player with excessive jitter? That's assuming the player is good enough to merit improvement in the first place. I think that once the real problem is understood, the solutions will be much easier to see.
-Chris
Hi dtses, Andy,
That one isn't very expensive considering you get a good PCB - stuffed and ready to go. Shock mount it and you might really have something.
I have a problem with some well known people's assemblies that cost a great deal more that may be about the same performance, or even less.
Now, the real question is, what is actually going to be helpful to jitter performance in a meaningful way? How easily can that be implemented? The "kit" in the last link may be required to tame a cheap CD player. But then the question begs to be asked - why? A cheap and nasty CD player will have far more serious problems than simply jitter! Why bother in that case?
So, as an exercise, why not define what characteristics are really needed to reduce a player with excessive jitter? That's assuming the player is good enough to merit improvement in the first place. I think that once the real problem is understood, the solutions will be much easier to see.
-Chris
I can see the AC rectification (you could use DC most likely, where the AC rectifier will provide polarity protection), 3 - pin voltage regulator (probably 3.3V) and clock oscillator buffer - so basic ingredients for a solid clock oscillator are all there.
The biggest problem that I can see from the photo is very poor choice of power supply decoupling capacitors - they should be little surface mount ceramics - NOT film type capacitors.
The other problem is the fact designer chose to use screw terminals for clock-out signal. This signal should be available at the mini-BNC type connector, the signal then should be fed to CD player board via appropriate coax cable.
For the money - it is a bargain with all basic ingredients present. If you are able to tackle the abovementioned issues - you’ll have good, solid clock for next to nothing
Very important factor in implementing the external clock oscillator is finding the ground point on your CD player PCB that has the lowest noise, and then using this ground point as the reference ground for the clock oscillator board.... and very low noise power supply (just by-pass the on-board AC rectification!)
There's even a ferrite bead to isolate two grounds: buffer IC ground and oscillator ground.... some like them and use them, some don’t. If the ground plane is properly implemented – there’s no need for ferrite beads at all….
Boky
Last edited:
It is not so trivial job to build a decent power supply if anyone want good performance clock.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.