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Implementation of ο1 on Marantz CD63 SE

omicron1: A low-jitter, low phase noise clock generator for upgrading digital audio devices

Re: Implementation of ο1 on Marantz CD63 SE

Postby amb » January 9th, 2018, 6:56 am

Crystals are 2-pin passive devices. An oscillator is active and requires power and ground for its internal circuitry. Sometimes the terminology gets confusing, as in this case.

For your DAC, disconnect XTO and inject ο1’s output into XTI.
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Re: Implementation of ο1 on Marantz CD63 SE

Postby franjam » January 9th, 2018, 1:20 pm

Ok thanks, I'm currently looking at this from the UK, https://www.ebay.fr/itm/1pc-TCXO-16-9344MHz-Crystal-Oscillator-NEW-GENUINE-ORIGINAL-UK-STOCK-/152638717121? would you mind looking at the specs and okaying it for me ? The price seems reasonable and no extra postage :D (I am awaiting pin measurements and dimensions from the seller as they aren't in the specs).

Also if I cut the trace to XTO is it a good idea to take out the entire track back to the cap...?

Lastly where is the best place to tap for the input pwr and ground ...directly at the out pin of the DAC 5V regulator? and at the ground of the caps I remove for example...? (having said that the whole of the top sheet of the pcb is the ground plane on the CD 63, so I just need to scratch the varnish off somewhere.. ;)
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Re: Implementation of ο1 on Marantz CD63 SE

Postby amb » January 9th, 2018, 4:42 pm

The oscillator you linked looks OK, but there is no information about its jitter or phase noise performance.

You don't have to cut any traces. Just remove X001, R002, C002, C003 and you would have isolated XTO and made it not-connected. You can then use the vacated "right side" pad of R002 or C003 as the injection point to XTI.

As for power and ground, the power can be tapped directly from the 5V regulator. The ground can be somewhere on the ground plane, preferably near the regulator too, so the supply return current from the ο1 is out of the way of the other DAC ground currents. I'm sure you can find a spot without having to scratch off the soldermask.

EDIT: Since your original circuit has the inverter inside the DAC chip, you should inject the ο1 output into the XTO pin instead (use the "left side" pad of R002 or C002).
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Re: Implementation of ο1 on Marantz CD63 SE

Postby franjam » January 10th, 2018, 12:56 am

Ok that seems clear...

As for power and ground, the power can be tapped directly from the 5V regulator. The ground can be somewhere on the ground plane, preferably near the regulator too, so the supply return current from the ο1 is out of the way of the other DAC ground currents. I'm sure you can find a spot without having to scratch off the soldermask.


Ccould I not simply use the center pin of the regulator as ground aswell..?

The oscillator you linked looks OK, but there is no information about its jitter or phase noise performance.


ok what should the measurements and figures look like ? For example I have one that quotes: Phase noise: -125dBc/1KHz , is this good? how is jitter measured?

Thanks for your patience, I realise I 'm well out of my league compared to many people using this forum :)
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Re: Implementation of ο1 on Marantz CD63 SE

Postby amb » January 10th, 2018, 4:30 am

franjam wrote:Ccould I not simply use the center pin of the regulator as ground aswell..?

Yes, if it's a 78xx-style regulator.

Note that if it's a 5V regulator, and you want to use a 5V oscillator, then you should take the power from the input of the 5V regulator to feed the ο1, not the output. Otherwise there won't be any dropout voltage for the ο1's onboard regulator to work properly.

ok what should the measurements and figures look like ? For example I have one that quotes: Phase noise: -125dBc/1KHz , is this good? how is jitter measured?

Yes, that is a pretty good phase noise figure. Not as good as the Crystek CCHD-957 series which has something like -148.9dBc/1KHz or -152dBc/1KHz, but better than IDT/Fox Xpresso series which has around -112dBc/1KHz. I must say that these numbers are affected by the test equipment each manufacturer uses, and may not be directly comparable. Also, ebay units from unknown manufacturers may not be truthful in their advertised specifications.

Phase noise is the frequency domain representation of jitter (which is time domain). A jitter-prone clock will have high phase noise. Some oscillators' specifications may include a jitter specification like "Jitter RMS", and low single-digit or less psec of jitter is good.
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Re: Implementation of ο1 on Marantz CD63 SE

Postby franjam » January 10th, 2018, 8:16 am

ok thanks for those explanations,

Note that if it's a 5V regulator, and you want to use a 5V oscillator, then you should take the power from the input of the 5V regulator to feed the ο1, not the output. Otherwise there won't be any dropout voltage for the ο1's onboard regulator to work properly.

If I'm reading the wiring diagram correctly the input voltage is 10.8v is there not a risk of frying the clock? Ok don't answer that just found the answer in the other thread, limit is 15V , Q811 is the DAC regulator,I have already replaced Q811 with an LM340T5.

I'm going to go for the TLC 5v clock, TLC are a reputable English company, its not too expensive and funds are starting to be a litlle tight :o ; i can always change it if the result is awful or if I come across something better ;) It's got to be an improvement on the existing quartz clock....yes? ( obviously talking myself into it here.. :P )

This brings me to the parts list..in this particular case does only note 5 apply or does notes 2 and 3 apply? what is SEL logic?
From what I understand I buy all the blanks plus U1, note 5 yes ?, ( i'm not counting the cable stuff ;) )
I'm essentially building the same one as for the DCX yes? just with a different frequency..
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Re: Implementation of ο1 on Marantz CD63 SE

Postby amb » January 10th, 2018, 10:35 am

The LM340T5 is only marginally better than the 7805. You should look at the σ78 for a much bigger improvement.

You are building a ο1 in single-frequency configuration, so follow the parts list notes accordingly. Also, the ο1 schematic diagram shows a dotted box around all the parts for dual-frequency application that you should not install. SEL is not used in a single-frequency configuration. Yes, note 5 under the parts list applies to you.

This one would be different than the one for DCX2496 in that you'll be using a 3.3V oscillator there (Crystek CCHD-957-25-24.576 recommended), and therefore also the 3.3V version of the ADM7150 voltage regulator.
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Re: Implementation of ο1 on Marantz CD63 SE

Postby franjam » January 10th, 2018, 1:09 pm

Great! I think it's straight in my head now :-)
I very much intend to look at o78 both for the Marantz and the DSP of the DCX, do you think it would make a difference for the cd player transport Q871 as well as Q811?
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Re: Implementation of ο1 on Marantz CD63 SE

Postby amb » January 10th, 2018, 3:07 pm

If the "transport" is basically all for the motor/laser and controls, then I don't see any benefit of upgrading the voltage regulator for it.

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Re: Implementation of ο1 on Marantz CD63 SE

Postby franjam » January 11th, 2018, 2:42 am

Ok I'll propably just transfer the LM340T5 chip over then when I replace Q811 with o78. EDIT: In fact i won't do anything of the sort as I've been referring to the wrong wiring diagrams :oops: , I've been looking at CD67 instead of CD63 ; many similarities but not always the same : only one 5v regulator, 2x12v +/- and one -24v rail with a 79W18 ..? Fortunately the clock and DAC layouts and parts are identical :D The input on the 7805 regulator is slightly higher at 11.5v but still within spec.
For some reason this .pdf file from HiFi engine won't allow me to take segments for pictures...? :(

I've ordered the TLC clock ; had a chat with the guy on the phone who was quite straight forward ; he used to use them himself in producing cd players and said that the noise and jitter specs were very good without being excellent. Which is good enough for me at this stage as it's so hard to find.
he also added that using a 74HC125 as a buffer after the clock using the same power source would improve it a lot..
Do you concur? Can you explain further...? ,(obviously I realise that o1 is not designed for this but i would like to understand :) )
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