› Forum › Digital line › The Well Tempered Master Clock – Building a low phase noise crystal oscilllator
- This topic has 31 replies, 10 voices, and was last updated 11 months, 1 week ago by seafood2017.
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08/07/2022 at 12:12 #1584The Well AudioParticipant
Since the original thread on diyaudio.com has been closed the topic is renewed here.
This topic is about low phase noise/jitter oscillator to be used in digital to analog conversion.
You can find the original thread on diyaudio.com at the following link
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17/07/2022 at 12:54 #1681multiblitzParticipant
I just want to order the next batch of parts for my upcoming Drixo-clocks and figured that the B82132A5401M000 is end of life and no stock anymore at Mouser…is there n alternative ? Digikey still has a stock, but I dont have enough stuff from them to order…alternatives only if there is no sound quality degration…otherwise I will just make up an order somehow from Digi…
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17/07/2022 at 13:00 #1683The Well AudioParticipantmultiblitz Said
I just want to order the next batch of parts for my upcoming Drixo-clocks and figured that the B82132A5401M000 is end of life and no stock anymore at Mouser…is there n alternative ? Digikey still has a stock, but I dont have enough stuff from them to order…alternatives only if there is no sound quality degration…otherwise I will just make up an order somehow from Digi…
You can replace the part with the EPCOS B82111E0000C024 (Mouser part 871-B82111EC24).
It’s a little wider but it should fit. -
12/11/2022 at 00:38 #1917lasercutParticipant
Andrea, I was about to put together DRIXO but notice the chokes I have do not match the current BOM
Mine:
B82132A5401M000
B82132A5301M000BOM:
B82111E0000C026
B82111E0000C024When I upload the BOM to mouser it to shows upper one , but viewing BOM in spreadsheet shows the lower one.
Which is correct?
If it is the lower part I wonder if anyone else had this error and is possibly using the wrong part in their XO.
- This reply was modified 2 years ago by lasercut.
- This reply was modified 2 years ago by lasercut.
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12/11/2022 at 00:50 #1920lasercutParticipant
**
Mine:
B82132A5401M000
B82134A5301M000 -
12/11/2022 at 11:45 #1922The Well AudioParticipant
These inductors have been replaced in the BOM because they are obsolete.
They are both correct, old and new parts. -
13/01/2023 at 09:44 #2046hughjamesParticipant
Andrea,
A question on the TWTMC-PPG-V2. I see the board is set up to accept 6.6 Volts as the power input. I’m presuming that’s intended for a pair of Lithium Batteries. True?
What’s the maximum and minimum voltage for avoiding damage and good performance?
Thanks,
Hugh
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13/01/2023 at 10:39 #2048The Well AudioParticipant
Allowed power supply voltage is 5V up to 7V.
Best phase noise performance are reached with 6V6. -
22/04/2023 at 23:44 #2382sigitaskParticipant
I need 11.xx MHz clock. What is better solution Drixo at 11 Mhz, or 5.xxx MHz and doubler?
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22/04/2023 at 23:52 #2384The Well AudioParticipant
Phase noise measurements are here:
https://www.thewellaudio.com/twtmc-drixo-phase-noise-measurements/
https://www.thewellaudio.com/twtmc-dbm/
Very similar, 5 + doubler has better 1/f noise while 11 MHz has better noise floor.
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22/05/2023 at 14:50 #2409canvasParticipant
Hi Andrea,
Recently, I acquired a phase noise measurement tool and did the measurment on my TWTMC_DRIXO 24.576 SC-Cut. However, it turns out the close-in performance (below 100Hz) is at least 20dB inferior than yours. My TWTMC_DRIXO is power from battery and both REF clocks are Morion MV89A (power by LT3042). Is there anything I should pay special attention to do a PN measurement? What would be the cause? Do you think it could be the sample variation?
Poting
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22/05/2023 at 14:54 #2414The Well AudioParticipant
Of course, there could be difference between crystals, but 20 dB looks too much.
Which phase noise measurement tool are you using?
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22/05/2023 at 15:14 #2415canvasParticipant
Hi Andrea,
The measurement tool is newly developed by a Chinese. He hasn’t put it on the shelf yet. The software is still under development, but the hardware is ready. I’ve done measurements on several 10Mhz OCXOs. The plots mostly coincide with manufacturer’s claims, except for few crystals (e.g. NDK SD2520 & TWTMC_DRIXO) on close-in.
Poting
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22/05/2023 at 15:40 #2417The Well AudioParticipant
Difficult to say, I should measure your oscillator with my Timepod to understand if there are differences.
Joseph K and Tbrowne diyaudio members measured some DRIXO oscillators and the measurements were the same I have made with the Timepod, maybe a little better in 1/f3 region. -
23/05/2023 at 12:37 #2418canvasParticipantThe Well Audio Said
Difficult to say, I should measure your oscillator with my Timepod to understand if there are differences.
Joseph K and Tbrowne diyaudio members measured some DRIXO oscillators and the measurements were the same I have made with the Timepod, maybe a little better in 1/f3 region.Hi Andres,
The manufacturer suggests “independent” battery power for everything. I guess I will try that first. Will come back to you soon, thanks!
Poting
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02/06/2023 at 02:59 #2421canvasParticipant
Hi Andrea,
I did the PN measurement again. This time both Ref clocks are bettery powered. DRIXO is shielded in a stainless can (a moded teacup). This is probably the best result I can get from it. I also attached the plot for NDK 2520SD 24.576M which I got from DIYINHK. The NDK plot is almost identical to the manufacturer’s claim, so I think my setup should be ok. The DRIXO is good at 1Khz dBc onward, but the close-in is still far from your measurement. May I ask how you ‘shield’ the DUT? I suspect this is probably the cause. Thanks.
Poting
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02/06/2023 at 12:25 #2426The Well AudioParticipant
The DUT was shielded in the Hammond box.
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07/06/2023 at 20:00 #2431hughjamesParticipant
Hi Andrea,
The TWTMC-PPG-V2 clock I bought from you a while back has made a fantastic improvement in my old Rotel CD player (used as a transport via spdif and I2S). CDs have never sounded so clean.
I’m scheming a similar upgrade to an old SACD/DVD player. I noticed that there was nothing on your web site for a 27 mhz clock. Is that by choice, or just out of stock?
If you don’t offer anything at 27 mhz, is there a chip oscillator (like the NDK ones) you would suggest?
Thanks,
Hugh
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07/06/2023 at 23:30 #2427canvasParticipantThe Well Audio Said
The DUT was shielded in the Hammond box.
This is probably the best from my Driscoll 24.576M. Shielded and battery powered.
The other pictures show my stainless shielding can for the PN measurement.
It appears that the clock needs to be shielded or the PN perofrmance will be vastly degraded.
Poting
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06/12/2023 at 18:42 #2595seafood2017Participant
Hi, Poting.
Does your mearsure tool need LPFs?
I have seen a measure tool on taobao which is familiar to yours, and it needs LPFs between clocks and it.
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09/06/2023 at 21:04 #2434The Well AudioParticipanthughjames Said
Hi Andrea,
The TWTMC-PPG-V2 clock I bought from you a while back has made a fantastic improvement in my old Rotel CD player (used as a transport via spdif and I2S). CDs have never sounded so clean.
I’m scheming a similar upgrade to an old SACD/DVD player. I noticed that there was nothing on your web site for a 27 mhz clock. Is that by choice, or just out of stock?
If you don’t offer anything at 27 mhz, is there a chip oscillator (like the NDK ones) you would suggest?
Thanks,
Hugh
27 MHz oscillator was never ordered. We can build the DRIXO at 27 MHz, but the problem is the MOQ for the crystal, at least 10 pcs.
As an alternative I would suggest NDK oscillator if you can find one at 27 MHz.
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12/06/2023 at 00:16 #2436hughjamesParticipantThe Well Audio Saidhughjames Said
Hi Andrea,
The TWTMC-PPG-V2 clock I bought from you a while back has made a fantastic improvement in my old Rotel CD player (used as a transport via spdif and I2S). CDs have never sounded so clean.
I’m scheming a similar upgrade to an old SACD/DVD player. I noticed that there was nothing on your web site for a 27 mhz clock. Is that by choice, or just out of stock?
If you don’t offer anything at 27 mhz, is there a chip oscillator (like the NDK ones) you would suggest?
Thanks,
Hugh
27 MHz oscillator was never ordered. We can build the DRIXO at 27 MHz, but the problem is the MOQ for the crystal, at least 10 pcs.
As an alternative I would suggest NDK oscillator if you can find one at 27 MHz.
Thanks Andrea.
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24/07/2023 at 09:29 #2442OnemindeParticipant
Hello Andrea and TWA community.
I am working on a RPi transport / streamer and fully differential and symmetrical PCM1794A DAC and want to use The Drixo & DBM platform, similar to what Doede is using for his DDAC.
My question is: Is it possible to shrink the PCB footprint / parts distance and combine the master clock and frequency doublers onto the same PCB ?
The goal is to reduce the overall size such that the master clock, RPi transport, FiFo and DAC can coexist in the same housing. PSU for all sections is located in its own box.
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24/07/2023 at 15:33 #2445The Well AudioParticipant
Oscillators and DBMs PCB layout was designed after several iterations in order to get the best performance as possible.
So, shrinking the layout would not a great idea.
Moreover, in order to avoid RFI/EMI, the best way is keeping oscillators and doublers outside the DAC box. -
24/07/2023 at 19:01 #2446OnemindeParticipantThe Well Audio Said
Oscillators and DBMs PCB layout was designed after several iterations in order to get the best performance as possible.
So, shrinking the layout would not a great idea.
Moreover, in order to avoid RFI/EMI, the best way is keeping oscillators and doublers outside the DAC box.Okay and thanks. I will carry on with my project and keep the clocks and their PSU in a separate chassis 🙂
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26/08/2023 at 14:59 #2458nguyen phuongParticipant
Hi Andrea
the doubler TWTMC-DBM work with power 12-24v. but which is the best voltage range to doubler TWTMC-DBM
Tks
Phương
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26/08/2023 at 17:19 #2459The Well AudioParticipant
You can use the same voltage you are using for the oscillators, usually we follow this way.
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01/09/2023 at 12:05 #2467The Well AudioParticipant
Someone should publish a better comparison chart like this on
https://www.diyaudio.com/community/threads/asynchronous-i2s-fifo-project-an-ultimate-weapon-to-fight-the-jitter.192465/post-7441661Just curious he forgot TWTMC-DRIXO and ACKO AKX22.
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05/09/2023 at 13:59 #2476KazumaParticipant
Anyway, the point is, at what price is it going to be. It couldbe a very good, good, or bad clock for the price.
For example ACKO for the price is qute qood, because it’s a “selected crystal” method (I suspect it is) of acheiving those specs, and is guaranteed per piece.
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05/09/2023 at 15:17 #2471
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06/09/2023 at 02:36 #2479canvasParticipant
In my opinion, the AKCO AKX22 is too good to be true. -110dBc@1Hz for a 22M XO is rare. The best 10Mhz OCXO from Taitien is rated -118dBc@1Hz which is close to -112dBc@1Hz for a 20Mhz if applicable. Taitien 10M OCXO is more than $2000 ea. I wonder how much it will cost for a AKCO AKX22.
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07/09/2023 at 21:25 #2483KazumaParticipant
On ackodac page it says “Price: from USD 680. Enquire”
Regarding the new Ian’s clock comparisons @diyaudio, there is one nuance: they are directly comparable ONLY on same crystal when measuring the DUT.
So, being fully transparent, he sould do such measurements when possible. And it IS possible with his new clock & drixo, for example. (And I bet he already did, but I doubt he would post the results)
Otherwise, you can have a situation, where phase noise is limited by individual crystal piece, and NOT the schematics solution itself.
This is what happened with canvas, I think.
Andrea, did you measured several crystals out of, or maybe a even full batch (of ten?), to reckon a typical discrepancy of a batch made at factory?
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