Anyone want to design a high end USB DAC?

[individual6891]

Quote:

Originally Posted by DaKi][er I didn’t order the boards, a friend go a whole panel done and had some room to add mine in as well, so the other boards in there aren’t mine Its getting sent to me express post tomorrow morning so fingers crossed I get it Friday

Pretty, Blue

Do yo think this will turn into a GB?

 

[clarke68]

[The newbie in back raises his hand]

Any chance you could reduce the number of SMD components on the 'group buy' version?

[Sits down and shuts up]

 

[00940]

the best parts only come in SMD today. USB receivers are very small, so are digital filters. DAC and regulators are rather small too.

It also make sense to go SMD to reduce the inductance of the decoupling caps.

Compared to the chips, the smd resistors are really easy to solder

(at least up to 0805)

 

[bg4533]

I find SMD isn't much harder and can be easier at times than through hole. I have a harder time trying to keep components from falling out when I flip them over to solder.

This layout looks a little cramped in places, but shouldn't be too bad as long as you plan out your soldering.

 

[clarke68]

Quote:

Originally Posted by 00940 Compared to the chips, the smd resistors are really easy to solder (at least up to 0805)

That's good to know...There's just so many of them, I was afraid that I'd blow it on my 20th resistor after spending a few weeks populating the rest of the board.

Quote:

Originally Posted by bg4355 I find SMD isn't much harder and can be easier at times than through hole.

Alright...I'm in!!! You talked me into it. Just gotta practice my "flood & suck" technique on some free samples from TI.

 

[Syzygies]

Quote:

Originally Posted by clarke68 Just gotta practice my "flood & suck" technique on some free samples from TI.

The pictures of "flood & suck" I've seen look worse to me than just soldering normally.

I use .015" solder, a 1/32" tip, a good iron, a magnifying glass and good light. I find a way to secure the chip so it doesn't skit around on me.

Ever notice how your handwriting is better some days than others? I wait for a good day, and just go for it. I'm pushing 50; my brother had the best hands in the family when he was 8. If you're closer to 8 than 50, you have no excuse!

 

[00940]

Quote:

Originally Posted by DaKi][er I’m not keen at all on the idea of re-sampling the signal at all and i think a few others would be against that as well

then a second PLL, with a VCXO would be an alternative for jitter attenuation. A tad more complex, I'm still trying to understand how it works.

It would also restrict the DAC to one input frequency or the VCXO will not be able to lock.

 

[Clutz]

I'd be in for a board buy.

Cheers,
Clutz

 

[Garbz]

Well if there is a groupbuy the cost of boards comes down. Prehapse we can design in (in know the size will increase in the order of a few sqin, but I'm not at all interested untill it has balanced outs.

Given that all is needed are another 2 dac chips, and 2 output stages it can be designed completely voluntraily. Don't need balanced, don't populate the negative sides.

 

[Porksoda]

Quote:

Originally Posted by Garbz Well if there is a groupbuy the cost of boards comes down. Prehapse we can design in (in know the size will increase in the order of a few sqin, but I'm not at all interested untill it has balanced outs. Given that all is needed are another 2 dac chips, and 2 output stages it can be designed completely voluntraily. Don't need balanced, don't populate the negative sides.

Or you could just do dual outputs...

Is this project still alive?

 

[robzy]

I have been wanting to design a high end USB DAC for a while now, the problem is that i just dont have the time nor knowhow.

I really really really would like to see a "isolation xformer to isolate the usb receiver, which would be bus-powered". I think that is one thing that would seperate make your design a high-end DAC rather than just a standard DAC.

Rob.

 

[DaKi][er]

Quote:

Originally Posted by Porksoda Is this project still alive?

In regarding mine, I’m getting there......
Just waiting on a new df1704, takes a bit to get one to Australia
I messed up some pins on it, but I know what I need to change to have it work

Also just need to figure out why my reg102's aren’t regulating properly, then its just about done

 

[robzy]

So there is no adding in of a transformer i take it?

Rob.

 

[DaKi][er]

Quote:

Originally Posted by robzy So there is no adding in of a transformer i take it? Rob.

not in mine, but it isnt hard to change to have one if someone gives a link to a suitable one and i'll try and fit it on the board

 

[bg4533]

I am still very interested and willing to help however I can to get this project moving.