24 bit audio boards

Doh!

Sorry, Paul.

One of the few things that I changed was an update to those pads to make the positive side of the output caps square instead of round to make the polarity clearer, but I must not have re-generated the planes afterwards.

The files are updated in github and there's a new oshpark project https://oshpark.com/projects/63HpdGfx

Paul, I have an extra board from my original build that I'd be willing to send you if you'd like to get started a bit faster.
 
Lucky that caught it!

I sent the revised files. I looked at them only briefly, to make sure I had the fixed version and they weren't corrupt. But I didn't do any sort of DRC check or trace out connectivity or compare with the schematic. I just sent the revised files. We're going to get 10 boards with whatever those files specify!

I'm not in a hurry on this. No need to send me that extra board.
 
@ kpc

I did some testing tonight. I did not have a spare SD cars, so no grabs. I did photo the scope. Will try to do it again tomorrow. I will need help interpreting. 2 pics attached. 1 of the 2 channels combined and the other which shows the output of 1 channel driven at 0 and the other channel driven full at 1k.
20150512_183001.resized.jpg20150512_182746.resized.jpg

I'll see if I can get a fob and grab the caps off the scope tomorrow.

Keith
 
In the right picture it looks like you are adding the signals with the oscilloscope in the digital domain.
Oscilloscopes in general have very bad dynamic range. To increase the dynamic range, somehow you have to remove the fundamental tone. This is either by filteing, or by cancelling. This should be performed in the analog domain. Only after that it can be sampled.
 
I've got a Digikey order almost completed, based on this bill of materials. Hopefully it's up to date?

But Digikey isn't finding these 2 parts.

Code: 
5.2uH,3,"L801 L802 L803",Coilcraft,MSS1038-522NLB

BAT4XAA,1,"U801"

Any suggestions or alternates?

EDIT: I was able to order the inductors directly from Coilcraft's website.
 
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Hey Paul, sorry I couldn't get back to you earlier. Coilcraft only sells through their website, but you can probably get something equivalent with the same inductance and footprint from digikey.

The battery thing is just a two headers. This is the pn I got:SBH341AS-ND
 
whollender's board looks awesome, but is probably overkill for me. I'm more interested in making a DAC and, following this, an ADC (Based on the PCM1803).

Is there any interest in this board with the teensy and the PCM5122? I do not have the time right now to build it and all the rest that goes with it, but did lay it out. It has the same basic layout of the RPi board with respect to ground scheme and such. I can release it to osh park if there is interest.
 

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It's probably overkill for most people :D

Paul, have you made any progress on getting a board built up? I really need to do better documentation, so please let me know if there's anything that is unclear.

BTW, I put up a hackaday.io page for this with more of the results in one place, and links to the github repo and a link to the OSHPark project (soon anyway).
 
whollender said:
Paul, have you made any progress on getting a board built up?
Click to expand...

The Digikey parts arrived a few days ago. The Coilcraft inductors arrived just yesterday.

Erin will be soldering the board next week, time willing. Her first priority is always shipping Teensy boards and testing+packaging more to maintain enough on the shelf so we can ship orders without delay. I've got one other soldering project in her queue... which has been sitting for a couple days already. I wouldn't be surprised if she ends up getting to your board near the end of next week.

Sorry, I'm far too busy to solder it myself.

I should also mention, the offer from reply #94-96 still stands....
 
PaulStoffregen said:
The Digikey parts arrived a few days ago. The Coilcraft inductors arrived just yesterday.

Erin will be soldering the board next week, time willing. Her first priority is always shipping Teensy boards and testing+packaging more to maintain enough on the shelf so we can ship orders without delay. I've got one other soldering project in her queue... which has been sitting for a couple days already. I wouldn't be surprised if she ends up getting to your board near the end of next week.

Sorry, I'm far too busy to solder it myself.

I should also mention, the offer from reply #94-96 still stands....
Click to expand...

I just wanted to make sure that you guys weren't having any issues getting it put together, because you seem to be the first to try (other than myself, of course :)).

I've been meaning to do a bit more documentation, so hopefully I can get something put together by next week.

I'll also get some of my testing code put up on github so that you can get going faster.
 
At the rate things are going, looks like the soonest Erin will start soldering will be Tuesday. But it could easily get pushed back. That's really up to Robin.

Any useful info you might have by Tuesday would be great. Otherwise, we'll just push forward... and see how it goes. I bought 2 complete sets of parts, so we can afford at least 1 really tough "learning experience".
 
I added the code I used for loopback sine wave testing to the github repo: https://github.com/whollender/SuperAudioBoard/tree/master/SineTestCode

I don't know how much real documentation I'll be able to get finished in the next few days, but I think (hope :)) that the assembly should be pretty straightforward. I tried to make the silkscreen pretty clear, but there may be some places where the components were too close together for silkscreen clarity, so you may need to refer back to the schematic or KiCAD files.
 
I'd like to remind everyone the free Super Audio Board (bare PCB) offer is still open.

8 bare boards are up for grabs.

All you have to do is order a Teensy 3.1 from PJRC, and request one of these super audio boards in the "Additional Instructions" box on step #3. The bare board will be added in your package at no extra charge.

View attachment 4393
 
PaulStoffregen said:
At the rate things are going, looks like the soonest Erin will start soldering will be Tuesday. But it could easily get pushed back. That's really up to Robin.
Click to expand...

I'm hoping to work it in to the production schedule this week. We should definitely be able to get it assembled by the end of next week.
 
whollender said:
Hey Paul, sorry I couldn't get back to you earlier. Coilcraft only sells through their website, but you can probably get something equivalent with the same inductance and footprint from digikey.

The battery thing is just a two headers. This is the pn I got:SBH341AS-ND
Click to expand...

Farnell is stocking some coilcraft, the closest I found was MSS1038-522NLC, not sure what the NLB and NLC stands for?
 
PaulStoffregen said:
I believe 6 of the bare PCBs are still available. Hopefully Robin can give us some updates as they ship?!
Click to expand...

That is correct, there are 6 of the super audio PCBs sitting on my desk waiting to be shipped. We've shipped 2 boards with orders where they will be requested.

If you are one of the 2 people who requested one of these audio boards, they were included in your order. I promise. :)
 
neslekkim said:
Farnell is stocking some coilcraft, the closest I found was MSS1038-522NLC, not sure what the NLB and NLC stands for?
Click to expand...

According to the datasheet, the last digit is the type of reel (or no reel at all), so you may want to be careful that you don't end up with a reel instead of a just a few parts :)
 
I've been reformatting the bill of materials into our standard format and I have a couple of questions. I'm having Erin soldering up a board as I type. :)

- Are the FB parts inductors? (FB301, FB302, FB401, FB501, FB601, FB701 & FB801, FB802)
- are Conn_3, and Conn_2 header pins? Are they single row headers?
- What is part BAT4XAA - U801?
 
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