Here some measurements on how the offset of the I2S clock to the DAM clock (before locking) influences the clock adjustment of the DAM.
I measured the DAM clock with no signal locked to the DAM first, then adjusted the I2S clock to that frequency plus an offset, then played an signal. I did that for offsets of approximately 0Hz, 1Hz, 5Hz, 10Hz, 20Hz, 50Hz and 100Hz.
Well we see that the magnitude of the oscillation at start as well as in the stable phase later differ, but the offset seems not to be the determining quantity.
For offsets of 20Hz and bigger there is an instant adjustment at the start.
I measured the DAM clock with no signal locked to the DAM first, then adjusted the I2S clock to that frequency plus an offset, then played an signal. I did that for offsets of approximately 0Hz, 1Hz, 5Hz, 10Hz, 20Hz, 50Hz and 100Hz.
Well we see that the magnitude of the oscillation at start as well as in the stable phase later differ, but the offset seems not to be the determining quantity.
For offsets of 20Hz and bigger there is an instant adjustment at the start.
With my newer "USB3-only" computer I get only a connection if I add an USB-hub inbetween - any hub I tested did the trick. I have several different serial interfaces, all need the hub.
LOL - you still don't get it because I think you are blinded by noise.. 🙂
We are still talking frequency deviations... 😉
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Sure. But I would also very much like to understand what is going on with clocking in the RME cards...
You still don't get the question at hand. We are talking about a slow (over minutes?) frequency change (mHz?) that is probably not possible to detect by any human. But it has audible consequences when one start to mix its output with other DACs. Comprende?
Read my lips:
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Read my lips:
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No its you who don't understand -we are not talking close in noice. We are not talking sound quality. Period. You have missed this aspect here for the last 3 weeks ;-) We are talking frequency stability over minutes / hours...
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Frequency is the rate of change of phase. How is a sudden frequency shift not expressible in terms of phase? Frequency change of a continuously running clock involves a transient advancement or retardation of phase, settling around a new average rate of change.
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I know that.
I say this now one more time and then I give up: We have to aspects discussed:
(a) A very slow and small frequency drift problem but creates DAC sync problems but initself probably not a SQ or "musical" pitch problem.
(b) A potential SQ problem affiliated with the frequency changes of the Si / DPPL.
Now, living sounds have discussed almost only (a) so it seems really strange to answer that PN measurements will be done soon - no?
Some of us (me included) hopes for a change in the design to mitigate problem (b) - I'm sure living sounds don't mind that either.
Andrea keeps on about PN - and yes even if I have a background in telecom it doesn't necessarily mean that I don't understand about the "eventual" benefit, what it is and the workings of low PN - right? Is it critical to ultimate SQ - I think the jury is still out on that one - maybe. But many have invested in it so well see. I think his mod & measurements adventure is an illogical activity on the 1021 - it will prove nothing really as I see it because the test will not be performed in any whatsoever scientifically environment and procedure.
We all now that a special made clock would have superior close in PN compared to a Si - so why do it? The reports I predict will come out to the executors benefit in any case - it will be a blame game that makes low close in PN "win" however it turns out.... SQ or/and measurements. Ladder resistors sound bad. PN is ruined by the bad layout - no SQ difference... it's just so meaningless and a waste of resources as I see it.
If Andera want to "prove" that low PN is better why not use his own upcoming board. It will be claimed superior in every aspect (and may very well be!?) so it's much better to use a bad oscillator on that platform to compare with because then the platform itself can not be a limitation.
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I say this now one more time and then I give up: We have to aspects discussed:
(a) A very slow and small frequency drift problem but creates DAC sync problems but initself probably not a SQ or "musical" pitch problem.
(b) A potential SQ problem affiliated with the frequency changes of the Si / DPPL.
Now, living sounds have discussed almost only (a) so it seems really strange to answer that PN measurements will be done soon - no?
Some of us (me included) hopes for a change in the design to mitigate problem (b) - I'm sure living sounds don't mind that either.
Andrea keeps on about PN - and yes even if I have a background in telecom it doesn't necessarily mean that I don't understand about the "eventual" benefit, what it is and the workings of low PN - right? Is it critical to ultimate SQ - I think the jury is still out on that one - maybe. But many have invested in it so well see. I think his mod & measurements adventure is an illogical activity on the 1021 - it will prove nothing really as I see it because the test will not be performed in any whatsoever scientifically environment and procedure.
We all now that a special made clock would have superior close in PN compared to a Si - so why do it? The reports I predict will come out to the executors benefit in any case - it will be a blame game that makes low close in PN "win" however it turns out.... SQ or/and measurements. Ladder resistors sound bad. PN is ruined by the bad layout - no SQ difference... it's just so meaningless and a waste of resources as I see it.
If Andera want to "prove" that low PN is better why not use his own upcoming board. It will be claimed superior in every aspect (and may very well be!?) so it's much better to use a bad oscillator on that platform to compare with because then the platform itself can not be a limitation.
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Stacked on C40, there are also a few more ceramics & a 10uF tantalum on the output of the reg. Going from 5 to 3.3v with the current load it does meet the dropout voltage requirement by a hair ~0.3v.
If I had the chassis room I would have supplied 3.3v+1.8v by LT3402+4th transformer but I also wanted this build to be compact, not get too hot and thus have low power consumption. It draws around 10 watts for everything including the front panel display + headphone amp.
Sitting on the drop out edge is not an ideal situation. Many regs needs, even if they do work, a few volts to do their best.
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For real...
living sounds, zfe and myself are talking about frequency stability because it's useful in the context at hand. And it's deliberate - wether you think its useless or not.
I obvious that you don't know what I understand.
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living sounds, zfe and myself are talking about frequency stability because it's useful in the context at hand. And it's deliberate - wether you think its useless or not.
I obvious that you don't know what I understand.
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I have nothing to prove, we build our devices for ourselves.
Then if someone was interested we share our designs with the diy audio community, otherwise we are happy anyway with the results we are reaching.
So if someone is interested will try the DAM upgrade you claim useless, but if you are not interested I can care less.
We are trying to help the audio community (and even without any commercial interest) but not the fanatic followers.
And finally I trust much more Pat Di Giacomo, NDK, MSB Tech, Charlie Hansen and so on rather than TNT and Soeren, sorry.
IMHO the best solution for your application would be the source slaved to the DAC without any FIFO, something like JLSounds USB to I2S slaved to the DAC master clock (obviously fixed clocks).
Unfortunately the DAM is not compatible with the above way.
So you did the "DAMenstein" board just to save the poor DAM owners out of their misery? Without having heard it.
Just to end this discussion from my side... Close in PN is extremely important in cellular radio base stations - I discussed this 20 years ago with the finest radio HW designers on this planet. And the PN impact is completely theoretically predictable as well as objectively verifiable.
See.
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Just to end this discussion from my side... Close in PN is extremely important in cellular radio base stations - I discussed this 20 years ago with the finest radio HW designers on this planet. And the PN impact is completely theoretically predictable as well as objectively verifiable.
See.
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Just to clarify, you cannot end nothing, you are not the owner of this forum.
And yes I have designed the upgrade for the DAM owners, I will sell mine as soon as I have ended the tests.
We are building our DAC (2 DACs to be precise) so I care less then zero about the DAM.
I'm simply debating about its designs choices, that's what one should do in a diy audio forum.
Even the threads about our devices are public and I have never insult anyone who has criticized our design choices.
BTW, I'm just assembling the DAM to hear its sound quality without any upgrade.
Sorry if it took long time, but we was busy with our new designs rather then thinking to the DAM1021.