The Well Tempered Master Clock – Building a low phase noise crystal oscilllator

Forum Digital line The Well Tempered Master Clock – Building a low phase noise crystal oscilllator

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    • #1584
      The Well Audio
      Participant

        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

        https://www.diyaudio.com/community/threads/the-well-tempered-master-clock-building-a-low-phase-noise-jitter-crystal-oscillator.261651/

      • #1681
        multiblitz
        Participant

          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…

        • #1683
          The Well Audio
          Participant

            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.

          • #1917
            lasercut
            Participant

              Andrea, I was about to put together DRIXO but notice the chokes I have do not match the current BOM

               

              Mine:
              B82132A5401M000
              B82132A5301M000

              BOM:
              B82111E0000C026
              B82111E0000C024

              When 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 1 year, 5 months ago by lasercut.
              • This reply was modified 1 year, 5 months ago by lasercut.
            • #1920
              lasercut
              Participant

                **

                Mine:
                B82132A5401M000
                B82134A5301M000

              • #1922
                The Well Audio
                Participant

                  These inductors have been replaced in the BOM because they are obsolete.
                  They are both correct, old and new parts.

                • #2046
                  hughjames
                  Participant

                    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

                  • #2048
                    The Well Audio
                    Participant

                      Allowed power supply voltage is 5V up to 7V.
                      Best phase noise performance are reached with 6V6.

                    • #2382
                      sigitask
                      Participant

                        I need 11.xx MHz clock. What is better solution Drixo at 11 Mhz, or 5.xxx MHz and doubler?

                      • #2384
                        The Well Audio
                        Participant

                          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.

                        • #2409
                          canvas
                          Participant

                            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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                          • #2414
                            The Well Audio
                            Participant

                              Of course, there could be difference between crystals, but 20 dB looks too much.

                              Which phase noise measurement tool are you using?

                            • #2415
                              canvas
                              Participant

                                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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                              • #2417
                                The Well Audio
                                Participant

                                  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.

                                • #2418
                                  canvas
                                  Participant

                                    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

                                  • #2421
                                    canvas
                                    Participant

                                      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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                                    • #2426
                                      The Well Audio
                                      Participant

                                        The DUT was shielded in the Hammond box.

                                      • #2431
                                        hughjames
                                        Participant

                                          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

                                           

                                           

                                           

                                        • #2427
                                          canvas
                                          Participant

                                            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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                                            • #2595
                                              seafood2017
                                              Participant

                                                 

                                                 

                                                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.

                                            • #2434
                                              The Well Audio
                                              Participant

                                                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.

                                              • #2436
                                                hughjames
                                                Participant

                                                  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.

                                                • #2442
                                                  Oneminde
                                                  Participant

                                                    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.

                                                  • #2445
                                                    The Well Audio
                                                    Participant

                                                      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.

                                                    • #2446
                                                      Oneminde
                                                      Participant

                                                        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 🙂

                                                      • #2458
                                                        nguyen phuong
                                                        Participant

                                                          Hi Andrea

                                                          the doubler TWTMC-DBM work with power 12-24v. but which is the best voltage range to doubler TWTMC-DBM

                                                          Tks

                                                          Phương

                                                        • #2459
                                                          The Well Audio
                                                          Participant

                                                            You can use the same voltage you are using for the oscillators, usually we follow this way.

                                                          • #2467
                                                            The Well Audio
                                                            Participant

                                                              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-7441661

                                                              Just curious he forgot TWTMC-DRIXO and ACKO AKX22.

                                                            • #2476
                                                              Kazuma
                                                              Participant

                                                                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.

                                                                 

                                                              • #2471
                                                                Kazuma
                                                                Participant

                                                                  https://www.diyaudio.com/community/threads/asynchronous-i2s-fifo-project-an-ultimate-weapon-to-fight-the-jitter.192465/page-463#post-7433057

                                                                  Even more than that, he forgot about NDK’s top line clock DUCULON

                                                                   

                                                                   

                                                                   

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                                                                • #2479
                                                                  canvas
                                                                  Participant

                                                                    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.

                                                                  • #2483
                                                                    Kazuma
                                                                    Participant

                                                                      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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