[ble0t]

*yawn*

I was sleeping so nicely

I'll send a friendly nudge to our reviewers and see how they are coming along. I didn't mean for it to take this long. Hopefully we can get some protos ordered soon

 

[Clutz]

Getting some reviews done is an excellent idea, especially with a fairly complicated layout and schematic like this. I'm still pretty excited about it though.

 

[dviswa]

Quote:

Originally Posted by Clutz Getting some reviews done is an excellent idea, especially with a fairly complicated layout and schematic like this. I'm still pretty excited about it though.

Second that

 

[MegaMeee]

thirded

although I don't think the schematic is that complicated... It could be much worse...

Just had a thought...

This thing is going to be tough to solder though don't you think.. I think i need to invest it some proper parts.. a magnifying glass for one

I bought a couple of 41hz.com amp 3's to try some surface mount soldering but only 1 of the two works and I have no idea why (not that I really care, I also bought a charlize which sounds a bit better IMO

)
The discrete components were fine to solder after i watched tangents tutorial but the tripath 2021 chip was pretty tough, so I think I will need to get some more appropriate tools for soldering IC's in the future..

 

[dviswa]

Quote:

Originally Posted by MegaMeee I think I will need to get some more appropriate tools for soldering IC's in the future..

Fine Desoldering braid's your friend. Speaking for myself, it is impossible not to put some solder bridges on those smd ics. There might be some with super duper dexterity and talent here, but I am not one of them. Taking care of inevitable bridges is the key.

 

[DaKi][er]

Flux paste is even better, you get it so the chip will only draw as much solder as it needs off the iron, and if anything bridges you can literally wipe them off with the iron, just keep the flux up to it

 

[dviswa]

Hi Guys,

Have'nt we waited enough for that review.

+1 for a prototype run

Regards,
Dinesh

 

[ezkcdude]

Well, since someone resurrected this thread yet again, I have a lingering I/V question. What are the advantages, in terms of audio, in using OPA1632 over individual op amps? Clearly, it is a simpler solution because fewer components are needed. But there are other op amps with better specs (e.g. lower Ib, Vo, etc). I suppose a disadvantage to using separate op amps for balanced output is that they would have to matched carefully. Was this a real concern? I guess I'm just curious as to the rationale that was used for making the design decision to use OPA1632. It's not that I'm trying to be critical, more like devil's advocate here. To me, the I/V issue is by far the toughest thing to settle on, so I'm hoping to gain some enlightement from more experienced designers/DIYers than myself. O.k., you can go back to sleep now

 

[00940]

Quote:

Originally Posted by ezkcdude But there are other op amps with better specs (e.g. lower Ib, Vo, etc). I suppose a disadvantage to using separate op amps for balanced output is that they would have to matched carefully. Was this a real concern? I guess I'm just curious as to the rationale that was used for making the design decision to use OPA1632.

I know very, very few opamps with better specs for our application. Look for settling time, slewrate, noise and gain bandwith. The only opamp we identified as a good competitor was the ths4631. And the difference is not big.

Add consideration about layout and availability and you have our reasons.

 

[Radfahrer1]

This project looks really interesting. I have been looking for DIY USB DAC in this price range for quite a while. So if its not too hard to build and there will be a pcb board group buy count me in.
I am sorry my knowledge in eletronics in not enough to contribe to the development

 

[Radfahrer1]

What's the status on this project? You guys haven't posted in a long while. I hope it is still alive

 

[ble0t]

My apologies...'real life' has been making an intrusion into my DIY time

Honestly, I hope to get a proto ordered ASAP. 000940 and myself are ironing out the very last little tweaks and I hope to post the latest version of the project soon.

 

[ble0t]

OK...here is the 'final' version of the board. I'm looking to order a couple protos sometime early next week, so if anyone sees anything, let me know. Enjoy

Schematic

Top Layout

Bottom Layout

Top + Bottom Layout

Top + Bottom + Top Silk Layout

 

[steinchen]

great! I got nothing to say but thanks for all your hard work, I'm really looking forward to build this project.

 

[ble0t]

OK...I'm going to need to order at least five proto boards in order to make this cost effective i.e. not ridiculously expensive. Four of the boards are already taken (00940, myself, my friend who is doing the PIC code, and dviswa), but I am willing to do an order of up to 8 boards. For this reason, anyone who wishes to give this a shot can PM me.

Disclaimer: This is a prototype design that has NOT been tested. Although we hope we did a good job designing this board, we cannot guarantee that you won't be left with more than just a large coaster. Also, these boards (due to their size) will cost at least $35 a piece, so keep this in mind!

EDIT: I totally goofed on the price...it's fixed now. Also, as far as the board house is concerned, we have very tight requirements and a majority of cheaper board houses would not be able to accomodate us in this regard, which is why it might be a tad more expensive.