Open-source USB interface: Audio Widget

Børge, will the AB-1.2 have s/pdif and I2S outputs like the 1.12/13 ?

No, it only has analog outputs like the AB-1.1. To experiment with digital outputs you'll need the AB-1.12/1.13.

One thing I have included in the AB-1.2 are two unpopulated discrete regulators. The board uses the same ADP151 as the AB-1.1 but makes it possible to play with your own LDO design.


Børge
 
AK4430.

Compared to the ES9023 I like that chip a lot. The AB-1.13 (same analog side as AB-1.2) packs more bass punch than the AB-1.1. That might be due to different caps, though.

But one thing I saw right away is that the AK4430 doesn't have the same clipping problem as the ES9023. And the fact that you can download a full datasheet and purchase the thing on Digi-Key (only in USD, though) are great plusses!

Børge
 

gioz

Member
2008-07-26 2:55 pm
It looks likr Gioz is connecting the module to a buffalo II. So it also depends on how the master clock is wired. There are just too many variables here so we need many more details to help with debugginng.

If the module can be set to uac2 mode according to the leds but it is mot recognized by OSX, it will ne useful to find out whether uac2 mode is recognozed by Win or Linux. If it is recognozed by ein or Linuz, then it is a Mac specific issue if not, then it is a hardware/ firmware issue.

Changing the host will.also check whether the win/linux PC USB port has enough joluice to.power the module without external +5V. If another UsB port is also not suppluing enough currwnt, them there might be a hardware problem somewhere.

Alex

Hi I tried the usb>I2S module (red version, clock on board) in voyage mpd on Alix 1d2. The UAC2 work but I have this problems:
file 16/44 work ok (no led status ON)
file 24/96 seem work but green status led is always ON
file 24/192 don't work (constantly stuffing) red led is always on (sometime red and green both on)
 
setting correct for Linux. Change linux quirk to quirk none if using win or mac.

Great that 24/96 works. Shows tyhat uac2 is functioning :)

24/192 may require more horsepower on host than what Alix board can deliver. Try with a Linux laptop or desktop. Make sure usb port is usb2, not usb1.1.

How is the SQ at 24/96?

Alex
 
Borges is right. The module LED's should flash at very slow rate (turning on or off once every 1 minute or more) when there is rate feedback lock.

What are the resistors put in around the clock divider U1 ? If you have a scope or logic analyzer check that the MCLK_MCU is getting 12.288 or 11.2896 Mhz. (You can measure J10 pin 2 for initial checking.)

Alex
 

gioz

Member
2008-07-26 2:55 pm
Borges is right. The module LED's should flash at very slow rate (turning on or off once every 1 minute or more) when there is rate feedback lock.
Alex

:scratch: with 24/96 files green led is always on

What are the resistors put in around the clock divider U1 ? If you have a scope or logic analyzer check that the MCLK_MCU is getting 12.288 or 11.2896 Mhz. (You can measure J10 pin 2 for initial checking.)Alex

The clock, divider and resistor are pre mounted by Borges
....I don't have scope
 
Last edited:
I tested the board before I sent it, and I believe the clock select resistors are correct. The way I see it you can try two things:
1) Use a Windows 7 computer in UAC1 and play the test tunes
2) See if you are able to locate a 'scope. Maybe you can ask at the audiofaidate list if someone has one nearby.

In UAC1 the red/green blink rate is faster, perhaps 0.5Hz or thereabouts.

To switch between UAC1/2, hold PROG (the button away from the JTAG header) in for 6 seconds. Then release PROG and click RESET (the button closest to the JTAG header).

Or even better: use a WidgetControl program (look for Windows ASIO Driver Download in my signature link). Remember to reset and read back after you change the settings.

The module was UAC1 when it shipped.

Børge
 
I tested the board before I sent it, and I believe the clock select resistors are correct. The way I see it you can try two things:
1) Use a Windows 7 computer in UAC1 and play the test tunes
2) See if you are able to locate a 'scope. Maybe you can ask at the audiofaidate list if someone has one nearby.

In UAC1 the red/green blink rate is faster, perhaps 0.5Hz or thereabouts.

To switch between UAC1/2, hold PROG (the button away from the JTAG header) in for 6 seconds. Then release PROG and click RESET (the button closest to the JTAG header).

Or even better: use a WidgetControl program (look for Windows ASIO Driver Download in my signature link). Remember to reset and read back after you change the settings.

The module was UAC1 when it shipped.

Børge

Hmmm, WidgetControl... It never seems to work in XP when you need it. Damn it - hours of my life will be lost installing Linux again just to be able to configure the widget. Isn't it time to scrap "support" for something that seemingly has lost it's popularity among the developers of WidgetControl? Just write that it is not supported under XP or whatever...

Brgds
 
Late-night hacking - great success!

Hi guys,

I just have to tell you what I did in my lab! Countless hours, soldering and lines of code have come together to where I have merged the USB-I2S module with my CD player project. Doing this is why I started getting into this whole USB business in the first place.

The two became friends immediately, and all the content I threw at it (16/44.1-24/192) came straight through to the DACs.

A lot of debugging and verification still remains. But the most important thing is that it plays!

Børge
 

Attachments

  • DSC_0562[1].JPG
    DSC_0562[1].JPG
    886.5 KB · Views: 431
Hi guys,

I just have to tell you what I did in my lab! Countless hours, soldering and lines of code have come together to where I have merged the USB-I2S module with my CD player project. Doing this is why I started getting into this whole USB business in the first place.

The two became friends immediately, and all the content I threw at it (16/44.1-24/192) came straight through to the DACs.

A lot of debugging and verification still remains. But the most important thing is that it plays!

Børge

Very nice Börge! So 2 leads for power in, 4 for usb and 2 is for IS out. That makes 8 leads - not bad...
 
Last edited:
marginally related: I just built a fanless mini-itx pc for audio use (mpd audio daemon and the usb audio widget).

the intel n2800 atom board is fanless, very low profile, very low power (10w or less, I think), has intel gig-e chipset onboard, video (vga+hdmi) onboard, takes m-sata DOM disk modules (what I have installed, shown near the 2 com and 1 LPT port headers, left side area). power is onboard so you just give it a 12v dc brick and off you go! disk module is, for me, a $25 4gb sandisk flash device that shows up as a regular old sata ssd.

this whole system is so low profile, you could fit it in a case half this height.

you need a recent linux kernel (3.4 is great). video is - sigh - closed-source and so this won't be any linux video box. but for audio its really nice! so low power and low heat. no wires inside! really industrial and I bet will run for years, undisturbed.

sorry for OT but this is my new pc front-end to the audio widget and its, uhm, teh new hotness... ;)

link to image: http://farm9.staticflickr.com/8001/7483404202_8fdc4cac78_b.jpg
 
i just noticed this thread...sorry being newbie ...i am lo0oking for a DAC and i was referred here....my transport is a Linux PC ...running puppy MPD...what DAC you guys recomend...also what is I2s will that help me buying this...

i am planning to run it with a AVR as AMP and then AMP to DIY speaker...

i guess i dont udnerstand what is I2s ....very excited to order this...
 
That is pretty cool!

I'm actually looking for two things, one Netflix+audio box at my stereo system, and one atom box I can send to the manufacturers to test the USB DACs.

Børge

for grins, I installed win7 on an e350 amd fanless board. its about on-par with the current atoms on cpu and it has its own 'fast video' onboard and on-chip. so, I gave it a try using MS's own media player (which we all know would be optimized well to display HD) and sure enough, it was quite acceptable playing 1080i ota HD. I did not try linux with this yet, but at least I can see the hardware running at its 'intended' (sigh) setting and it does have enough guts to play HD pretty well, and fanless.

the intel cedartrail is too new for me to even care about for video and I'm only using it for a general linux pc (build, test and play audio) and so far, its more than good enough for that. if linux can get its video working with HD well, it will then be my preferred box.

the mSATA has been working well and I like it a lot. screws right down to the motherboard and stays secure as can be (physically). absolutely love that aspect! its one reason I picked that n2800 board, in fact.

I remember only about 4 yrs ago, it took a dual cpu of core2 (or better) and a very good video card to do HD and not drop frames in obvious ways. today, both, the intel and AMD fanless mini-itx boards can push HD and not have any obvious defects in the video. this means that dedicated set-top video and audio boxes are now not *required* anymore to get perfect A+V (and doing it fanless/silently.)

for video and windows, either would be fine. for video and linux, probably neither. for usb and general reliable fanless use: both are fine. the intel will be easier to find and source, though. I do prefer the intel gig-e NIC and I always have.