Your favourite DAC project (post here) ?

[hagtech]

the addition of an energy storage element would make the timing of the edge more indeterministic

Absolutely not. No more indeterminate than the straight RC (which already has a storage element). In fact, the removal of noise improves the jitter situation.

You are correct, however, in that the inductance adds a delay, roughly equal to the risetime. That is why you have to do it to all the digital lines, to maintain relational timing.

jh

 

[ash_dac]

Hi,

So these series resistors before the dac....

I suppose one can only tell what the square waves look like by using the correct equipment, and measuring them since in the models \ datasheets for receivers / filters only perfect squarewaves are produced.

My Philips cd723 has 3 series resistors on the I2S (changed to 20ohm) built into the design.



Kind regards,


Ashley.

 

[rfbrw]

Hi,

So these series resistors before the dac....

I suppose one can only tell what the square waves look like by using the correct equipment, and measuring them since in the models \ datasheets for receivers / filters only perfect squarewaves are produced.

My Philips cd723 has 3 series resistors on the I2S (changed to 20ohm) built into the design.



Kind regards,


Ashley.

This is precisely the kind of topic covered by High Speed Digital Design and there is more on this in the publications section of Howard Johnson's site www.sigcon.com

 

[Guido Tent]

Re: Re: Discrete DAC

When I implemented your clock in a Philips player i also added the clock to the controller with a 10 ohm (standard 0,1W mini) resistor. I just did it, thinking it would stop reflections.

I have seen this in Pedja's design (where it is called "optional LPF resistor" without a value; and the DDDAC has 20ohm in the clock to the DAC.

I am curious if this should be a non-inductive (e.g. pressed carbon) type; is 6 - 10 ohms enough? Or does it matter a lot on circumstances?

Hi

No need for low inductance, but don't use wirewound, I like carbon types.

Some experimenting is needed on the values, as optimisation of risetime differs from gate bto gate

best

 

[Guido Tent]

Re: Re: Re: Your favourite DAC project (post here) ?

Hi, Guido.

I'm going to order your DAC but one question before. A friend of mine from Moscow (ZEUSLAB), who build more than 10 your DAC's with immutable success told me that the quality of Digital PCB ( 4 layer, gold finish) is noticeably fall-off. So was it just some kind of bad batch or whatever?

Thank you,
Valery.

Hi

Honestly, this is the first time I hear about this, haven't had feeback from Zeuslab, and if I recall correctly, I never sold that much PCB's to one person.

Nevertheless, if PCB's seem to be faulty, they should be returned to me for inspection.

By the way, they have silver immersion finish now, in order to meet leadfree requirements.

best

 

[Valery]

Re: Re: Re: Re: Your favourite DAC project (post here) ?

Honestly, this is the first time I hear about this, haven't had feeback from Zeuslab, and if I recall correctly, I never sold that much PCB's to one person.

Nevertheless, if PCB's seem to be faulty, they should be returned to me for inspection.

By the way, they have silver immersion finish now, in order to meet leadfree requirements.

best

Thank you, Guido.
Several people bought your KITs & Zeuslab just assemble them, so he didn't ordered so much. Anyway he told me that this DAC is the best he ever heard. O.K. then, I will place my order.

Regards,
Valery.

 

[Gcollier]

Re: Fedde Bouwman's NONOZ-III

1) NONOZ-III

2) http://jwg.student.utwente.nl/fedde/nonoz3.html or via http://www.fedde.tk/

3)
Pros: Low cost, good sound, easy to build.
Cons: No PCB-layout (had to do my own), CS8412/8414 difficult to source.

4) I absolutely love this little DAC. Performance is very good (especially for the price) and it's easy to build and so cheap that you can basically fit it anywhere. The board only requires a single supply of 11VDC or more, so stealing the supply voltage for it inside existing equipment shouldn't be a problem in most cases

Pics of my prototype. The PCB is my design and measures app. 63x45 mm

/U.

Any chance you can post or even email me the PCB layout for that little DAC board. It's pretty much exactly what I have been looking for. I would like to replicate the design in EAGLE and make some very minor modifications before I etch my own boards.

Thanks.

G.

 

[Nisbeth]

Sure, YGM!


/U.

 

[pku]

I would like to built 24 bit/192 DAC, which recieve I2S digital input format and have I/V stage can be modifyed later. I will replace the old DAC section in my cheap and poor DVD. . Does anybody can advise me or give me a circuit ? Thanks forwardly

 

[kenny12]

i have also been searching for a nonoz III pcb. do u have any spare boards?

 

[Nisbeth]

Nope, but YGM anyway


/U.