DAC project completed

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jitter said:
I've been following this thread but I will sign off as I feel the thread has completely derailed. It was not much to start with anyway, it was as useful as saying "we made something great" full stop.

And now you've also started contradicting yourself because in post #73 you wrote:


Which IMO contradicts thew following from post #80:



Why didn't you or Kurt mention this in the first place (I take it you mean the same with "ring core" as "toroid")?



Kurt in NOT the engineer, I am! That's why Kurt did not mention this!
Please slow down... We only have 1 prototype, and the schematics is not yet finished. That's why we did not post them!

But I will try to post some old drawings of the analog stage tonight.
 
In regards to the scematics - be aware that the servo circuit is not there. This is not completely concluded yet.
As far as we do know at this time is, that it has to have cut of frequenzy lower than any rediculous fantasy could ever imagine.
Otherwise it shows up in sound reproduction, but in a very different way than caps do.

Btw. the analog stage is the far most important part of this design along with powersupplies and layout.

The design in the scematic was chosen long time ago, as we knew it worked perfectly for our purpose.
Most of our experiments has been on filtration, supplies, servo system, components and a lot more.
I hope we will soon be able to supply more bullitproof DIY info for you, as we do want yours to perform as well as ours.
But please be patient - we are not working with this professionally, thus it takes time.
Be aware that the amp itself has not got a very high PSSR. So you really have to be carefull with the supplies, a few LM´s or 78/79´s will not do at all. It has to have very low noise supplies wich only can be acomplished by carefull active and smooth filtration.
Large cans are of no use in this design.
 
Erlend Sæterdal said:


Nonfeedback? what about R 11 and 12 ? Otherwise I like the design. I think it can get better using led diodes as current generators in the input.

P.S. You know me as Diamagnetic.


R11 and R12 is NOT used in a NFB chain.

I know that some people believe, that even a emitter-follower, is 100% Feedback. But it goes against their own transostor model.... :xeye:
 
Erlend Sæterdal said:
Hurtig said:



R11 and R12 is NOT used in a NFB chain.

I know that some people believe, that even a emitter-follower, is 100% Feedback. But it goes against their own transostor model.... :xeye:




The same old diskussion Hurtig.

Anyway... this is not negative feedback. It is not possible to argue that this is negative feedback, unless you go against the transistor beeing a current controlled current source, where an input current to the base, controls a larger current in the collector.

If you feel that you can argue this as feedback, without going against the transistor model, please do so. If not, then let's move on!
 
cvo2009 said:
I,m ashamed of being Danish, BUT in contradiction to what you might think, not all Danes are like these two guy, we can be reasonable person's.

cvo2009

To be honest all Danish people I have met (and all people from Scandinavia btw) have been extremely polite, humble and tolerant and the development of this thread was a real surprise for me,that prompted my paranoid accusations of false identity...


:xeye:
 
luxury54 said:
Dear designers,great work you did here!
I also like the sound of CS4398 very much but with a slightly different analog stage approach.
I have bought a very cheap ready available dac kit from HK using the same CS8416 + CS4398
The original sound of it was very bad and different to what i obtained after some tweaking. First of all the chinese guy implemented cs8416 pretty wrong so i had to change the PLL filter


Hi luxury54
I cant open your profile for some reason, but in case you are not Lukasz Fikus it is always polite to quote where you get your information from: http://www.lampizator.eu/LAMPIZATOR/LAMPUCERA/CD DAC Lampucera lampizator.html

In case you are Lukasz then great job :D! I have bought the small dac an will be trying the sanyo/wima upgrade soon. I am not quite sure about the tube part as I am not that skilled (only a hobbyist).



On topic:
Hurtig and KvK got the same response on Danish hifi sites so you are not the only ones who find them a bit mind-boggling.
To be fair, nice job on the DAC, but in all honesty what is the point of your "pad-me-on-the-back" behaviour here and on Danish sites?
I too will remove my subscription from this thread as I fear the only reason you do this is to get the attention (don't feed the troll).
 
dear Havoc08,
I'm not Lukas but it was not him who "invented" that small PLL modification for CS8416 - the new values are in the updated datasheet but the chinese guy making this kit seemed not to care since it's working with old values too
anyway the first guy on some forum who did observe this was LEO from this link (and Lukas followed after this)

http://theartofsound.net/forum/showthread.php?t=315
 
luxury54

Do you now have a finished and Housed DAC, you can share with us.
Also is your cathode follower setup for stereo or mono, I am also wanting to apply this design after transformer out stage i.e dac>2 Audio transformers>cathode follower, just finding it difficult to find a tutorial for beginners.
I had a look at the lamizators web site and though he had a lot of info I could not see a how to paper.
I have been participating on the "Experience with this DIY DAC ?" thread and one of the members has also been experimenting with the cathode follower.
Thanks
 
Well here we go again!
Fore those interestet in some details of the project, I enclose links to PDF files Cabinet

The DAC has been changed in some ways, we actually added an ASRC so that the DAC chip now runs @24/96.
The sample rate converter chosen is AD1896 which is the same as the TI 40 something.
This devise should actually eliminate incoming jitter, and only ad it´s intrinsic jitter, which acording to datasheet is extremely low.
Not shown is the clock PCB, which was chosen as a small adon PCB, leaving some freedom for later revisions of clocking the ad1896. Btw the clock will be a very low jitter clock, with its own low noise discrete regulated powersuply.

This makes the DAC sound even better regarding resolution, smoothness and also some kind of musical clarity, its a bit hard to explain, but most of what happens is in the time domain. It seems as if attack, sustain and decay is in a better harmony, wich reveals timbre and removes overexposion of attack.

For those who asked earlier, we ordered 10 pcb´s.
 
The TI is completely the same chip, with the same data, though they descibe the following differences in the datasheet:

PIN COMPATIBILITY WITH THE ANALOG
DEVICES AD1896 (SRC4192 ONLY)
The SRC4192 is pin-and function-compatible with the AD1896
when observing the guidelines indicated in the following
paragraphs.
Power Supplies. To ensure compatibility, the VDD_IO and
VDD_CORE supplies of the AD1896 must be set to +3.3V,
while the VIO and VDD supplies of the SRC4192 must be set
to +3.3V.
Crystal Oscillator. The SRC4192 does not have an on-chip
crystal oscillator. An external reference clock is required at
the RCKI input (pin 2).
Reference Clock Frequency. The reference clock input
frequency for the SRC4192 must be no higher than 30 MHz,
in order to match the master clock frequency specification of
the AD1896. In addition, the SRC4192 does not support the
768fS reference clock rate.
Master Mode Maximum Sampling Frequency. When the
input or output ports are set to Master mode, the maximum
sampling frequency must be limited to 96kHz in order to
support the AD1896 specification. This is despite the fact that
the SRC4192 supports a maximum sampling frequency of
212kHz in Master mode. The user should consider building
an option into his or her design to support the higher
sampling frequency of the SRC4192.
Matched Phase Mode. Due to the internal architecture of
the SRC4192, it does not require or support the matched
phase mode of the AD1896. Given multiple SRC4192 devices,
if all reference clock (RCKI) inputs are driven from the
same clock source, the devices will be phase matched.

But the funny thing is, they don´t even really exist.
The Analog 1896 does go for about twice the price of 4192, but data is the same.
 
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