The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator

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diyiggy

diyiggy

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ernesternest said:
Good morning Andrea,

having a TWTMC-AIO with SC Cut crystals in my drawer and would like to use it with my FIFOPI. I know, it need 9 to 12 V but I do not know the current needed. Would be great to know if i could use an existing small transformer for that or get a bigger one.

BR

Ernst
Click to expand...


Hi,

Also don't forgett the Fifo Pi has not the same DIL socket positions as the older FIFO and MC-FIFO boards. One of the DIL sockett is 180° flipped which is meaning you can use the Andrea's adaptator only with one of the two frequencies - if the adaptators are directly stacked on the TWTMC-AIO. However if you use the DIL adaptaors with the uf-l connector option you can use both frequencies because the flipped socket of the FifoPi will not arm. Proble is a short 2" uf-l cable will increase the jitter (which is not too much a problem with a chip like the TDA 1541 but is for the nowadays last high speed dac chips).
The new Discroll board arriving soon has not this problem of jitter introduced by the extra length of uf-l cable if understanding correctly). Anyhow, you will need the DIL adaptators with 2 uf-l cables as the new Discroll board is a standalone board managing both crystals (- so not stackable as the ancient TWTMC boards on the Iancanada DIL socket)

I don't know if I'm clear enough, anyway if wrong someone will correct my inputt.
 
diyiggy

diyiggy

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It's a question for the PC forum section where you should open a thread with further details around your question. To make it short, noone can answer to this question without knowing what the hat you are talking about after the I2S Rpi outputt. Because you are talking about two different things related to Rpi board: the usb inputt and the I2S outputt.

Hope that helps.
 
ernesternest

ernesternest

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TWMTMC-AIO current demand

I figured out, the current demanded by a TWTMC-AIO board is 165 mA, when fed ba a 12V switcher.
An LM317 fed by a 3.5W 9V transformer couldn't supply enough juice. Voltage was down to 7V.

Iggy, yes I'll need a cable in my configuration. I want tu use SMA connectors instead of uf.l since they are more reliable in the long term. Problem here is the non existence of really short SMA cables. The shortest I just found was 4". I don't know if there are even shorter existent. I guess I can manage the issue with the FIFOPI clock orientation and I'll see what comes next.

BR

Ernst
 
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diyiggy

diyiggy

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Ernst you can certainly go for a hybrid solution with the older 2 oscillator boards on the FifoPi :


- one TWTMC DIL adaptator directly stacked with the FiFoPi & the TWTMC-AOP for the frequency you listen the most in your albums library
- second one with only the SMA for the second crystal - (as for the ancient boards length is important, 2" uf-l cable would beat the 8" SMA in theory... but with the TDA1541...well jitter matters less, imho both confs will maybe give the same result at ears !)


Well for the brandnew dual frequency standalone board, one must have 2 cables anyway as it's not stackable on any of Iancanada stuffs - and also the length seems to have no impact is the new design as Andrea noticed.
 
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ernesternest

ernesternest

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Iggy, with SMA plugs it is possible to turn the adapter upside down and it should work with some more modifications or I have to cut some part away. And I found 4inch cables :)
The bad things with uf.l is the wear after some put on and off.

Felipe

If it helped, I would be glad, but the board is more than 2 years old and I guess they are all in use now.

BTW, having 9v psu current rises to 175 mA.

Cheers, Ernst
 
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N

nano35

Member
Joined 2017
Thanks for the photo.
The stack of 5 boards and a big grey box on the right of the photo, what are they? I am curious.
Nano35


Supersurfer said:
Just use the dil pcb from Andrea. You can connect with u-fl, sma or directly. I used u-fl first but directly is a bit better. See attached pictures.

It will be a problem fitting two of these dil pcb’s though. But Andrea is designing new boards to fit the fifopi; I think using the clocks on fifopi is the most used implementation of the clocks.

Regards,
Click to expand...
 
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Hifoli

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Joined 2019
Hi, just a quick question as I am just designing a battery power supply to use with Ian‘s fifopi and the new Driscoll boards (correct me if I’m wrong but they should be compatible with the fifopi, in the way that i can „just“ replace the existing 45.1584/49.1520 MHz clocks?)
So question is what power rails should I build for the Driscolls? Is it the same what I found on the clap boards: „15V for the oscillator and +5V for the squarer“?

Thanks a lot.
Greetings oli
 
N

nicpom

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Joined 2010
Supersurfer said:
Hi,

I had the chance to compare three clocks today:
-crystek cchd 957
-accusilicon as318-b-451584
-Andrea Mori sc-cut, driscoll pcb without oven.

All 45mhz samples.

The Andrea Mori clock is the best sounding by far; it delivers lots of openness, air, focus and a warm tone without any harshness.
The accusilicon was second best and at quite a distance from the Andrea Mori clock. There was more harshness, less dynamic and a bit fatuiging in comparison.
The crystek is a bit behind the accusilicon with a tad more harshness and similar overall sound.

All clocks were used on an Ian Canada fifopi, battery/supercap powered and bypassed ldo’s, mounted on an Allo Usbridge Sig, feeding my, tuned to the max, 4 deck dddac.

I have been living happily for quite some years with the crystek clocks but now after using the Andrea Mori clock for about a year I cannot imagine going back to this type of clock anymore. The music is so much more natural and “analog”. You have to hear the difference to understand how much there is to gain with good clock design.

I cannot wait to try the new driscoll design clock with the 5mhz chrystals. These promise to be even better!


Regards
Click to expand...


Hello,


I recently did a similar comparison, with a McFifo based streamer, feeding a Denafrips Terminator DAC. Clock was a TWTMC-D Sc-cut 45.158 MHz, with TWTMC-OVN, on a TWTMC-D&D board providing power.



My findings are quite similar to the ones of @Supersurfer, but I also included a Neutron Star 2 Clock in the round-up. I were not able, but I am still trying, to have access to a Pulsar clock, which is probably "the guy to beat" here.



TWTMC performs quite better than AS318 and CCHD-957, but Neutron Stars 2 outperforms it. Difference is limited, and considering the cost of Neutron, it is a very good result from TWTMC.



If newest clocks are better than old ones, they are probably an end game choice.
 
Supersurfer

Supersurfer

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Joined 2013
nicpom said:
Hello,


I recently did a similar comparison, with a McFifo based streamer, feeding a Denafrips Terminator DAC. Clock was a TWTMC-D Sc-cut 45.158 MHz, with TWTMC-OVN, on a TWTMC-D&D board providing power.



My findings are quite similar to the ones of @Supersurfer, but I also included a Neutron Star 2 Clock in the round-up. I were not able, but I am still trying, to have access to a Pulsar clock, which is probably "the guy to beat" here.



TWTMC performs quite better than AS318 and CCHD-957, but Neutron Stars 2 outperforms it. Difference is limited, and considering the cost of Neutron, it is a very good result from TWTMC.



If newest clocks are better than old ones, they are probably an end game choice.
Click to expand...

That is an interesting Comparison, I have not heard the Neutron Star and did not buy it (yet) due to the asking price.

I have learned that the clock performance is quite depending power supply quality.
Was the ps to both clocks comparible?

I just noticed that the Neutron Star 2 is at 20% discount!

Regards,
 
N

nicpom

Member
Joined 2010
Supersurfer said:
That is an interesting Comparison, I have not heard the Neutron Star and did not buy it (yet) due to the asking price.

I have learned that the clock performance is quite depending power supply quality.
Was the ps to both clocks comparible?

Regards,
Click to expand...


In this test, Neutron clocks were powered by a sigma11 PS. The addition of a MPAudio MD-HPULN after the sigma11, did not give significant improvements.



TWTMC was powered by its standard PS , based on LT1085, so maybe there are margins of improvement there.
 
1

1audio

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Joined 2004
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I read through the hype on the Neutron Star: NewClassD NeutronStar2 6.000 Its interesting and uses a bunch of tricks I have used in the past. The noise measurements on the power supply are really hard to interpret or relate to more industry standard measurements. And at lower frequencies the noise measurement is somewhat suspect since pretty much everything has flicker noise. I did not see any measurements on the phase noise. A jitter claim of 1 pS which is quite respectable. And the transformer trick is really good. I have used that successfully on some soundcard mods. I left the existing crystal as a bandpass filter for the injection lock to further reduce jitter/phase noise. It seemed to work well.
 
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