I have built a differential oscillator and after testing a few mods, I could post a schematic if there is any interest.
The outputs will drive the + and - inputs of the comparator to achieve better psu noise rejection.
Or one output drives a reclocker at raw clock frequency, while the other output is divided down to word clock or whatever.
The outputs will drive the + and - inputs of the comparator to achieve better psu noise rejection.
Or one output drives a reclocker at raw clock frequency, while the other output is divided down to word clock or whatever.
Here is the schematic from my working prototype.
Next step is to add more parallel FETs.
For conversion to square, I intend to use AD9687 which has ECL outputs.
And use ECL as far as possible for the rest of the DAC.
Next step is to add more parallel FETs.
For conversion to square, I intend to use AD9687 which has ECL outputs.
And use ECL as far as possible for the rest of the DAC.
Last edited:
Added the AD9687 and it looks very good.
AD9687 with only 2,7 ns propagation delay is much faster than AD8561 that has 7 ns.
AD9687 with only 2,7 ns propagation delay is much faster than AD8561 that has 7 ns.
Last edited:
Very beautifully Bernhard!
How this beauty influences a sound? As it is beautiful?
It is possible to describe in a few words. Judging by frequency it for TDA1541?
How this beauty influences a sound? As it is beautiful?
It is possible to describe in a few words. Judging by frequency it for TDA1541?
Not very original as Wildmonkeysects already invented it in 2002:
http://www.diyaudio.com/forums/digi...cillator-just-wont-oscillate-3.html#post25748
http://www.diyaudio.com/forums/digi...cillator-just-wont-oscillate-3.html#post25748
Last edited:
Thanks, I did not see this.
Anyway, I did not claim an inventionjust a schematic and he did not invent it either.
Coupling caps should be used for exactly 50% duty cycle and referencing the comparator to its own ground pins, not somewhere else.
Thanks, this beauty has not been connected to a DAC yet as I have not finished the comparator part and the shield.
I am listening to the previous version with less ideal grounding and it sounds a bit better than a pair of industrial clocks, however I have no specs or datasheets from manufacturers.
The influence on sound...
The clock is located inside the DAC and it fixes all the typical degradations caused by SPDIF & bad CD player clocks, for example corrupted tonal balance, irritating sound, lack of precision and separation.
I don't like the superlative vocabulary that is used regularly in this place 😉
The clock frequency has nothing to do with TDA1541, it is just comfortable to divide down to what my transport expects as word clock.
What is important with any clock: The oscillator part must be shielded. Otherwise it will pick up all the noise it can get, you can see it on a spectrum analyzer.
Industrial clocks are not put into hermetically sealed metal cases for fun or for the shiny look.
There are clock modules offered for audio tuning, that have discrete oscillators on pcbs and no shield. Just forget about it.
Last edited:
IMHO the usual tech-talk-bla-bla with lots of claims what specs are better than on other clocks, based on spice simulations of a yellow black box but no schematic and no single word how it is achieved.
:**:
Noise in the oscillator signal that comes from the psu appears common mode on the differential inputs of the comparator and will be rejected.
A single ended clock would modulate the supply voltage.
The differential clock draws constant current and keeps the supply clean.
So, in theory the differential clock should be superior.
Perfect shielding against electric and magnetic fields is maybe most important.
Last edited:
Yes, happens!🙂
What at you now vision, has passed a lot of time, about 7 years?
The scheme has reached perfection?
If I may ask a couple of questions :
Why use 2SK152 instead of other JFETs ?
And why not an extra (JFET) driver stage at the oscillator for the comparator a la Hagclock ?
Thanks in advance,
Patrick
Why use 2SK152 instead of other JFETs ?
And why not an extra (JFET) driver stage at the oscillator for the comparator a la Hagclock ?
Thanks in advance,
Patrick
Hi Berhard,
Thanks a million for the explaination.
A friend of mine also explained to me that the differential signal can become a noise generator, into other parts of the circuit.
Can we make PCB trace for the clock output ? Should we choose point-to-point floating cabling instead, like in the products from Audiocom (single-ended, btw).
If so, which cable is appropriate ?
Thanks a million for the explaination.
A friend of mine also explained to me that the differential signal can become a noise generator, into other parts of the circuit.
Can we make PCB trace for the clock output ? Should we choose point-to-point floating cabling instead, like in the products from Audiocom (single-ended, btw).
If so, which cable is appropriate ?
Attachments
> For conversion to square, I intend to use AD9687 which has ECL outputs.
I guess you meant AD96687 ....
Patrick
I guess you meant AD96687 ....
Patrick
- Status
- Not open for further replies.