Go Back   Home > Forums > >

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 13th December 2019, 11:42 PM   #1901
andrea_mori is offline andrea_mori  Italy
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Quote:
Originally Posted by clsidxxl View Post
Thank you Andréa for the report,what is the supply voltage of the new oscillator,always 6 Volt and 3Volt?
Not yet defined, it's a prototype to be tested and refined.
It's a different design with different power supply, maybe batteries powered.
  Reply With Quote
Old 14th December 2019, 12:47 AM   #1902
Terry Demol is offline Terry Demol  Australia
diyAudio Member
 
Terry Demol's Avatar
 
Join Date: Apr 2002
Location: *
Quote:
Originally Posted by andrea_mori View Post
This is the first measurement of the new oscillator prototype with the Laptech SC 3rd overtone crystal at 5.6448 MHz.

The plot compares the phase noise performance of the new oscillator (green plot) against the Crystek CCHD-957 at 22.5792 MHz (blue plot) and a custom made OCXO from HCD at 11.2896 MHz (pink plot).

The Crystek was powered by Lifepo4 battery supply, while the other 2 oscillators was powered by standard regulators (this explains the spurs in the plot).

There is still improvement margin, since the power supply is not the best (to be measured with Lifepo4 batteries), it was measured on the fly in air without any shielding box, there isn't an oven.

Hope this was a Christmas gift.

Andrea
Pretty amazing spec. Well done!

TCD
  Reply With Quote
Old 14th December 2019, 03:17 PM   #1903
wlowes is offline wlowes  Canada
diyAudio Member
 
wlowes's Avatar
 
Join Date: Mar 2007
Location: Toronto
Looks great. Now I can look forward to buying a Laptech SC 3rd overtone crystal at 5.6448 MHz and putting it into service in 2020. I hope you will do another group buy for the 5.6MHz oscillator.
  Reply With Quote
Old 14th December 2019, 03:32 PM   #1904
diyiggy is offline diyiggy
diyAudio Member
 
diyiggy's Avatar
 
Join Date: Jan 2019
At clsidxxl, You meant best to use LiPoFe without reg (while not stable volttage value but lowest noise) ?

My experience with Christeq is i have better result with ldo and c cors traffos than LiPo with the best low noise low ppsr LDOs... sonically speaking..

Hey thanks Andrea, nice picture...
__________________
The Paradox of the anti-stupidity vaccine : the fools don't want to take it...
  Reply With Quote
Old 14th December 2019, 07:07 PM   #1905
gabor80 is offline gabor80  Hungary
diyAudio Member
 
Join Date: Nov 2012
Location: Hungary, Pest
Beautiful measures, Andrea. Much better than the AT-cut results at the first page of the topic.
  Reply With Quote
Old 14th December 2019, 07:25 PM   #1906
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
Sorry to toss some cold water on the measurements but ÷2 in frequency and phase noise drops by 6 dab so making comparisons with widely different frequencies can be misleading. The 5 MHz seems the sweet spot for OXCOs but it needs to be multiplied to be useful. So you need to figure out multipliers or dividers. The Crystek divided may look much better.
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 14th December 2019, 07:48 PM   #1907
mr_whocares is offline mr_whocares  Germany
diyAudio Member
 
Join Date: Mar 2005
Location: germany
Quote:
Originally Posted by andrea_mori View Post
Not yet defined, it's a prototype to be tested and refined.
It's a different design with different power supply, maybe batteries powered.
battery powered? integrated battery design? :-)
super! me gusta la bateria ;-)
  Reply With Quote
Old 14th December 2019, 07:52 PM   #1908
clsidxxl is offline clsidxxl  France
diyAudio Member
 
clsidxxl's Avatar
 
Join Date: Sep 2012
Location: Strasbourg
Quote:
Originally Posted by andrea_mori View Post
Not yet defined, it's a prototype to be tested and refined.
It's a different design with different power supply, maybe batteries powered.
Thanks Andrea,you should consider the Supercapacitor power supply,some like 5Volt,it could be done with the UcConditioner of Ian.


diyiggy,i use the SC Cut of Andrea,this one must be feed by 2 different voltage,3,3V and 6V,for the slicer at 3,3V i alternately used 1 Lifpo4 and LT3045 of LDOVR,I did not hear any difference between the two, at least it was not obvious,
I'm waiting for the new design of Andrea,I want to try the Supercap power supply.
______________________________________________

Ad Astra 'long course pilot,they look good in their skin.
  Reply With Quote
Old 14th December 2019, 07:59 PM   #1909
Joseph K is offline Joseph K  Hungary
diyAudio Member
 
Join Date: Dec 2004
Location: gran sasso
Andrea, nice result.
May I ask, where did You get access to a Timepod?
What is used as reference?

And it's true that the Crystek looks worse than it really is, because of the frequency.

One should subtract 12dB fron the Crystek values as shown in the graph.
Now the difference is 40dB at 1Hz. After subtraction that will be 'only' 28dB difference, at 1Hz. 😅😆😀

Ciao, George
  Reply With Quote
Old 15th December 2019, 12:22 AM   #1910
andrea_mori is offline andrea_mori  Italy
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
For reference below you can find a comparative table with the best OCXO on the market. The top performers in the range are the Oscilloquartz BVA 8607 and the Wenzel ULN, that means many thousands dollars to get one of these (no chance to get a frequency suitable for digital audio).

I also attach the phase noise plot of the two top performers. As you can see at 10 Hz from the carrier the phase noise performance of the prototype oscillator is very close to the performance of the best oscillators on the market.
The top performers are better at 1 Hz from the carrier, but as I said in a previous post I think there is still improvement margin by shielding the new oscillator and by feeding it with a better power supply.

It's true that the Crystek is a 22.2792 Mhz oscillator, so you have to divide it by 4 to do a better comparison, and theoretically its phase noise will improve 12dBc, but in the real world I'm not sure you really get 12dBc better phase noise performance. Anyway, assuming 12dBc better, the phase noise difference is 'only' 36 dBc (148.7 - 112).
Attached Images
File Type: jpg OCXO_Comparative_Table.jpg (319.4 KB, 532 views)
File Type: png Oscilloquartz_bva_8607_phase_noise_1.png (16.9 KB, 552 views)
File Type: png Wenzel_uln-10MHz-5MHz.png (22.6 KB, 533 views)
  Reply With Quote

Reply


The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillatorHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
low jitter crystal oscillator IC beta tester needed. yizhou Digital Line Level 4 28th April 2013 06:13 AM
Circuit wanted for a Low Phase noise 100MHz Clock JohnW Digital Source 58 26th June 2012 09:28 AM
New Ultra Low Phase Noise Oscillator from Crystek wktk_smile Parts 7 25th August 2011 08:16 AM
Low jitter 30MHz crystal oscillator? Kuro Parts 2 1st April 2010 01:27 AM
Tube Crystal Clock Oscillator poynton Everything Else 3 25th August 2008 06:32 PM


New To Site? Need Help?

All times are GMT. The time now is 06:31 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki