Lars Nielsen DAC, comments?

[LennyK]

hi

Enybody built Lars Nielsen DAC?

http://home.worldonline.dk/hifiside/ecdafsp.htm

any comments?

best regards

Lenny

 

[Mark A. Gulbrandsen]

I would be very tempted to build the Digital section, but to use the Pass Labs D-1- I/V and output stage. It would be a bit more complex but is much more advanced than Lars simple output stage is. Not to say his does not sound good...as I'm sure it does. I just like the stuff that Nelson does in general. I also find Lars power supplies a bit odd, and not the usual high end stuff. Perhaps those parts are easier for him to get in his location.....
I certainly do give him credit for putting it all together!
Mark

 

[HenrikKronborg]

Mark,

Did you build the digital section of Lars's DAC?

I myself are very tempted to do so. Would just like to hear some opinions first.
Would also like to know more about a more "high end" like psu

Henrik

 

[tschrama]

I noticed the PCM1730 too. Looked like a very nice chip for a simple, small parts count DAC.

So I ordered the chips and got them yesterday. The PCM1730E is a SMD, a very, !very! small one. It looks too small to solder by hand. A good PCB might help. Does Lars Nielsen sell PCB's? I would be very interested.

The Lars Nielsen design looks good to me. The power supply is perfectly fine. These cap-multipliers have a PSSR of 70dB typical up to the MHz range. Very high frequency might be transmitted through the transistors CE capacitance. I figure you need a shunt regulator in series after a cap-multiplier to block that. That should give a PSSR of about 110dB up to 10's of MHz. For I/V I would use a discrete design just for fun.

Regards,
Thijs

PS
Although all specs are given for 24bit only, I would say that low level (-60dB) 16 bit performance might not be up to par. Does anybody know how this chip deals with 16bit data? Is it rescaled to fit 24 Bit data? Can we then convert the 24bit data diagrams to 16 bit performance diagrams by adding 50dB to the Y-axis?

 

[Mark A. Gulbrandsen]

No, Unfortunately I have not had the time as of yet. we are VERY busy at work...but thats a good thing too. I will let you know when I do....and I'm also interested in how the 16 bit performance might come out......
Mark

 

[Elso Kwak]

Site down?

Hi,
Is Lars Nielsens site down? I got a 404 error...

 

[tschrama]

Hi Elso,

I'll sure be interested in your opinion of this design. Do you know of any SMD SOIC to DIP adaptors for thios tiny tiny chip.

Regards,

Thijs


http://www.diyhifi.dk/projekt2.html

 

[Elso Kwak]

Thanks!!

Hi Elso,

I'll sure be interested in your opinion of this design. Do you know of any SMD SOIC to DIP adaptors for thios tiny tiny chip.

Regards,

Thijs


http://www.diyhifi.dk/projekt2.html

Hi Thijs, Thanks for the working link.
What can I say about about this DAC?.
To start with the powersupplies See the high speed diode thread for better alternatives for the 1N4001. Still wondering about the arrangement of the rectifiers...
The emittorfollower regulator is similar in basic design to my triple Darlington, but a simple zenerdiode looks crude..
Ask Joko about opamp as IV-converter

Browndog has nice SOIC to DIP adapters
www.brndog.com

 

[Petter]

New site for the DAC: http://www.diyhifi.dk/projekt2.html

Petter

 

[tschrama]

Thanks for the link.


gr,
Thijs

 

[PTSOUNDLAB]

PCB

Hello,

there is a pcb on Lars site, but the dimensions of the bitmap are enlarged when we take the *.bmp.
http://www.diyhifi.dk/layout1.html

There is this comment but I don't speak this language ?

"For at sikre optimal billedkvalitet, er printlayout og komponentplacering præsenteret i fuld opløsning.
Brug printerens zoom funktion for at tilpasse størrelsen efter målebåndet på 50mm. En god kopimaskine
kan også bruges til at justere størrelsen."

Pascal.

 

[Elso Kwak]

Re: PCB

Hello,

there is a pcb on Lars site, but the dimensions of the bitmap are enlarged when we take the *.bmp.
http://www.diyhifi.dk/layout1.html

There is this comment but I don't speak this language ?

"For at sikre optimal billedkvalitet, er printlayout og komponentplacering præsenteret i fuld opløsning.
Brug printerens zoom funktion for at tilpasse størrelsen efter målebåndet på 50mm. En god kopimaskine
kan også bruges til at justere størrelsen."

Pascal.

Hi Pascal ,
I don't speak the the language either but what I make of it sounds like:
For a optimal image quality of the printlayout and component placement I found following solution:
Use the printers zoom function ..............................50mm [probably using some fixed measure pasted or glued into the layout to reference to]
You can use every good copy (Xerox) machine to adjust to the right scale...


I hope I am not too far off.
Next month I have to practice Greek (holiday), Oh boy that's a different piece of cake ........
Salutations cordiales ,
(That's French by the way)

 

[PTSOUNDLAB]

PCB

Thank you Elso,

have you received my postal mail for dac schematic ?

Cordialement (like "salutation cordiales" in french

Pascal.

 

[Elso Kwak]

Re: PCB

Thank you Elso,

have you received my postal mail for dac schematic ?

Cordialement (like "salutation cordiales" in french

Pascal.

Hi Pascal.
I mailed the schematics yesterday,
Bonne nuit........

 

[PTSOUNDLAB]

Thanks

Thank you Elso,

good night (Bonne Nuit) too (a toi aussi)

Cordialement.

Pascal.

 

[HenrikKronborg]

PCB on Lars's site

Hi

I made the pcb yesterday. Here's how I did it.

Save the layout pictures. In AcdSee you set the picture to specified size. With a 300 dpi resolution the size is 6.20 x 6.20.
With 600 dpi it's 5.20 x 5.20.

Worked fine on a 2 different HP printers.


/Henrik


P.S.

I find the pcb pattern a little to tight for home making. Hope to get some comments from you guys

 

[HenrikKronborg]

Screenshot

Here the settings window:

 

[guzzler]

Sorry to dig up a rather old thread, but I was wondering if anyone had the schematic for the PCM1730 DAC (Lars Nielsen) one, as the old sites all seem to be dead, and I couldn't Google it.

Thanks very much

 

[Lars Clausen]

You might be able to contact him here: http://www.diyhifi.dk

 

[guzzler]

Thanks Lars, I'll give that a try.