Re: Re: Re: CLC filter
Your circuit might not have worked. My ALW versions power clock circuits beautifully. Dead stable and 10 uV noise/1 MHz. Also monitored on 400 MHz scope.
What do you mean by 'You like to screw quoting systems fmak' ???
Adding capacitance to XO before HC-- can help actually. Basically, matching is important.
---------------------------------------------------------------------------------Elso Kwak said:
Your circuit might not have worked. My ALW versions power clock circuits beautifully. Dead stable and 10 uV noise/1 MHz. Also monitored on 400 MHz scope.
What do you mean by 'You like to screw quoting systems fmak' ???
Adding capacitance to XO before HC-- can help actually. Basically, matching is important.
No capacitance on the 1st reg O/P -> 2nd I/P Amazing that it doesn't oscillate. Decoupling the adj pin to ground probaly will then.
The thick wires are so stiff that they are the real suspension, not the rubber bands.
The thick wires are so stiff that they are the real suspension, not the rubber bands.
Regulators for Clock Circuits
I tried the ALW version....
🙄
You need a low noise RF-regulator for clock circuits [no more hints]
😉
I tried the ALW version....
🙄
You need a low noise RF-regulator for clock circuits [no more hints]
😉
davidsrsb said:
Yes you need very flexible wires indeed. Yes the LM317 not applied as in datasheet!
More peanut gallery comments...
National semi *recommends* using a decoupling cap (.1uF) on the LM317 input pin. Why take chances... there should be one. I also feel that a 470uf main filter cap is under sized. I'd want to see at least twice that amount IE; 1000uF.
The LM317 is a 1.5AMP device. Under worst case conditions, this circuit draws 100ma, which is right at the hairy edge of what single 78L05 can deliver. Clearly, to be cautious, a smarter choice would have been a single LDO LT1086-5 device from Linear Technology. You get the benefit of Low Drop Out protection and 5 volt regulation and minimal parts count. The logic behind why two LM317's were used escapes me since attempting constant current regulation is overkill here.
The HEX inverter is almost entirely wasted. A buffer was created by using two inverter gates, basically keeping the Oscillator output in phase with inverter output... but why. No real need that I see... though it does look like they were going for a sort Schmitt-Trigger circuit with the inverter.
I would have used something like a buffer with open-drain output also known as 74AHC1G07 from Philips and would have the open drain buffer output tied to VCC though a 10K resistor so you get a TTL level HIGH when the gate is OFF. The 74ahc1g07 is a single gate, 6 pin, small footprint device. Ideal for use in a specialized circuit such as this.
But hey, I'm NOT a designer.
National semi *recommends* using a decoupling cap (.1uF) on the LM317 input pin. Why take chances... there should be one. I also feel that a 470uf main filter cap is under sized. I'd want to see at least twice that amount IE; 1000uF.
The LM317 is a 1.5AMP device. Under worst case conditions, this circuit draws 100ma, which is right at the hairy edge of what single 78L05 can deliver. Clearly, to be cautious, a smarter choice would have been a single LDO LT1086-5 device from Linear Technology. You get the benefit of Low Drop Out protection and 5 volt regulation and minimal parts count. The logic behind why two LM317's were used escapes me since attempting constant current regulation is overkill here.
The HEX inverter is almost entirely wasted. A buffer was created by using two inverter gates, basically keeping the Oscillator output in phase with inverter output... but why. No real need that I see... though it does look like they were going for a sort Schmitt-Trigger circuit with the inverter.
I would have used something like a buffer with open-drain output also known as 74AHC1G07 from Philips and would have the open drain buffer output tied to VCC though a 10K resistor so you get a TTL level HIGH when the gate is OFF. The 74ahc1g07 is a single gate, 6 pin, small footprint device. Ideal for use in a specialized circuit such as this.
But hey, I'm NOT a designer.
Re: Regulators for Clock Circuits
May be your clock, but not others. I can measure no appreciable RF noise. What about all these clocks around that are powered by 7805s?
Strange coming from someone who likes supersonic spikes in non OS DACs!!
Why should I not use my own system of referral
-----------------------------------------------------------------------------------Elso Kwak said:
May be your clock, but not others. I can measure no appreciable RF noise. What about all these clocks around that are powered by 7805s?
Strange coming from someone who likes supersonic spikes in non OS DACs!!
Why should I not use my own system of referral
pwillard said:
PW,
I am really cheap, so this clock is interesting. The clock module looks like the Tent modules.
The power supply looks more like something desgned to power slowet devices. To impove on this, would using LT1086CT here instead of LM317 help any?
George
Wow wow wow, this thread attracts so many responses. Thank you again for all the input.
Please bear in mind this is a cheap cheap kit but the fact is it improved the sound quality of my vintage Pioneer T-07A to great extend. I am using the T-07A as drive only and is connecting it to Dack 2.0 NOS DAC. Perhaps the age of my T-07 is a problem that a small modification generates so much improvement.
My last question is about the numbers of available clocks in the market that could cost 10x of this cheap cheap kit is numerous, can I expect to improve my CD by even greater extend by installing any of them in my aging T-07A? Or is it worthwhile to modify this cheap cheap clock to perform even better?
.
Please bear in mind this is a cheap cheap kit but the fact is it improved the sound quality of my vintage Pioneer T-07A to great extend. I am using the T-07A as drive only and is connecting it to Dack 2.0 NOS DAC. Perhaps the age of my T-07 is a problem that a small modification generates so much improvement.
My last question is about the numbers of available clocks in the market that could cost 10x of this cheap cheap kit is numerous, can I expect to improve my CD by even greater extend by installing any of them in my aging T-07A? Or is it worthwhile to modify this cheap cheap clock to perform even better?
.
My last question is about the numbers of available clocks in the market that could cost 10x of this cheap cheap kit is numerous, can I expect to improve my CD by even greater extend by installing any of them in my aging T-07A? Or is it worthwhile to modify this cheap cheap clock to perform even better?
------------------------------------------------------------------------------------
If you really want to know, send it to jocko or JohnW (search diyhifi.org) for measurement. Many of the leading XO modules are made to order in China!! No one can tell you objectively without measurement.
The other way to do it is to use best practice in terms of PS and coupling, and pick the one that sounds best!!
------------------------------------------------------------------------------------
If you really want to know, send it to jocko or JohnW (search diyhifi.org) for measurement. Many of the leading XO modules are made to order in China!! No one can tell you objectively without measurement.
The other way to do it is to use best practice in terms of PS and coupling, and pick the one that sounds best!!
See previous discussion on the Hifidiy clock
http://www.diyaudio.com/forums/showthread.php?s=&threadid=64779&highlight=
http://www.diyaudio.com/forums/showthread.php?s=&threadid=64779&highlight=
Re: See previous discussion on the Hifidiy clock
Hi.
Jean-Paul's comment in the thread probably sums it up nicely :-
Cheap
Looks good
better than 99% of standard clocks
Andy
Ruach said:
Hi.
Jean-Paul's comment in the thread probably sums it up nicely :-
Cheap
Looks good
better than 99% of standard clocks
Andy
George,
As I said, I'm no designer, but I dislike engineering based marketing pizzaz. I'm not saying this kit doesn't work great. It's a good price and it has what it needs... a quality crystal oscillator at a good DAC frequency.
Other people have tried to indicate that cascading regulator chips is bonus... it was TENT, I believe that originated this, but I'm guessing here.
What I see here is a nicely made circuit board, with some major marketing fluff and a tad bit more complicated than it needs to be to make people feel maybe it's somehow different or unique.
Why would you use LM317's, for example.? Lets see, In the Datasheet of the LM317 it reads "They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators."
Well, now, that means this must be a SUPER regulator. Maybe we should realize that this part was designed in the 1970's and maybe, just maybe, a better 3-terminal regulator chip has been designed since then.
The reason I mentioned the Linear Technology part is because it's *is* a newer design and it has excellent specs. The line and load regulation specs for the LM317 and the LT1086 part nearly identical. So why would I prefer a Single regulator? KISS principle.
It's down to one 1 Part versus 6 parts and seems like a bargain to me if you get the same results. Pricewise, the LT1086-5 is $3.00 as compared to $0.75 for an LM317, so this is not about price, but do you really want more parts when less would do just as well?
Now, I'll admit that the benefit of using dual regulators exists. You see, each of the regulators only has to dissipate part of the difference between 12V rail and 5V output, unlike a single part. However, by using a LDO device like the LT1086 part with a 1V Drop Out, you can supply the circuit with 6.3VAC transformer instead of 12V, thus bringing your dissipation way down.
As I said before, the current draw of the circuit is about 100ma, which is well within the tolerances of the regulator and therefore it is not stressed. "Not stressed" means good regulation.
The Crystal Oscillator Can is where the accuracy is. I'm not trying to make trouble here by saying this, but... asking someone to make a custom frequency crystal oscillator package with less than +/- 50 PPM variance is as simple as "asking". Nearly all of the crystal oscillator manufacturers will or do make higher quality units. Citizens, for example, makes such a part for about $3.00.
While I could probably make a clock source myself for about $15 (and I probably will), I'm not disputing that the Cheap Clock Kit for $30 works well or not. I am also not saying that it is not a good bargain. It's super for anyone that doesn't like building from scratch and where things at $149.00 might be a bit too costly.
Me personally, I would initially start by replacing an on-board crystal with just an oscillator can with minimal "glue" components, using the available 5V supply for the existing logic and then compare that to a "kit" solution. We are talking a maximum of 30 additional milliamps here, which is about as much as adding Blue LED.
WHAT ME WORRY?
As I said, I'm no designer, but I dislike engineering based marketing pizzaz. I'm not saying this kit doesn't work great. It's a good price and it has what it needs... a quality crystal oscillator at a good DAC frequency.
Other people have tried to indicate that cascading regulator chips is bonus... it was TENT, I believe that originated this, but I'm guessing here.
What I see here is a nicely made circuit board, with some major marketing fluff and a tad bit more complicated than it needs to be to make people feel maybe it's somehow different or unique.
Why would you use LM317's, for example.? Lets see, In the Datasheet of the LM317 it reads "They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators."
Well, now, that means this must be a SUPER regulator. Maybe we should realize that this part was designed in the 1970's and maybe, just maybe, a better 3-terminal regulator chip has been designed since then.
The reason I mentioned the Linear Technology part is because it's *is* a newer design and it has excellent specs. The line and load regulation specs for the LM317 and the LT1086 part nearly identical. So why would I prefer a Single regulator? KISS principle.
It's down to one 1 Part versus 6 parts and seems like a bargain to me if you get the same results. Pricewise, the LT1086-5 is $3.00 as compared to $0.75 for an LM317, so this is not about price, but do you really want more parts when less would do just as well?
Now, I'll admit that the benefit of using dual regulators exists. You see, each of the regulators only has to dissipate part of the difference between 12V rail and 5V output, unlike a single part. However, by using a LDO device like the LT1086 part with a 1V Drop Out, you can supply the circuit with 6.3VAC transformer instead of 12V, thus bringing your dissipation way down.
As I said before, the current draw of the circuit is about 100ma, which is well within the tolerances of the regulator and therefore it is not stressed. "Not stressed" means good regulation.
The Crystal Oscillator Can is where the accuracy is. I'm not trying to make trouble here by saying this, but... asking someone to make a custom frequency crystal oscillator package with less than +/- 50 PPM variance is as simple as "asking". Nearly all of the crystal oscillator manufacturers will or do make higher quality units. Citizens, for example, makes such a part for about $3.00.
While I could probably make a clock source myself for about $15 (and I probably will), I'm not disputing that the Cheap Clock Kit for $30 works well or not. I am also not saying that it is not a good bargain. It's super for anyone that doesn't like building from scratch and where things at $149.00 might be a bit too costly.
Me personally, I would initially start by replacing an on-board crystal with just an oscillator can with minimal "glue" components, using the available 5V supply for the existing logic and then compare that to a "kit" solution. We are talking a maximum of 30 additional milliamps here, which is about as much as adding Blue LED.
WHAT ME WORRY?
Now, I'll admit that the benefit of using dual regulators exists. You see, each of the regulators only has to dissipate part of the difference between 12V rail and 5V output, unlike a single part. However, by using a LDO device like the LT1086 part with a 1V Drop Out, you can supply the circuit with 6.3VAC transformer instead of 12V, thus bringing your dissipation way down.
-----------------------------------------------------------------------------------
The LT1086 is one noisy regulator 0.03%V if memory is correct. There are much better and newer LT and other regulators about.
It should not be used as a clock supply; even a selected 7805 with suitable output cap is better for noise. You can get 50uV in a good one; otherwise about 80 uV (1 MHz bandwidth)
-----------------------------------------------------------------------------------
The LT1086 is one noisy regulator 0.03%V if memory is correct. There are much better and newer LT and other regulators about.
It should not be used as a clock supply; even a selected 7805 with suitable output cap is better for noise. You can get 50uV in a good one; otherwise about 80 uV (1 MHz bandwidth)
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