Open-source USB interface: Audio Widget

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??? The Audio Widget is a USB interface ??? Maybe I don't quite understand what you are asking for? How good an ADC are you after? Build or buy? Big project or just need to get to work measuring?

The SDR widget is a USB Audio Class 2 interface for an AK5394A. You could build it. I think you need to make boards and flash the USB chip to get it going. The original supply are long gone. There are few comparable alternatives.
 
Sorry, I never got a notification for your reply.

I just need the best ADC I can get for a low price. Yeah, I know. It needs galvanic isolation too.

I could make boards if I had a very concrete idea of what should go on them, although I've never done digital and it would eat up a lot of my time.
 
Hi zdr,

The USB DAC 128 Mk 3 has four HW changes: 1) it uses the same ADP151 3.3V regulator for the MCU as for the analog parts, 2) there is no clock divider as MCLK passes straight to the MCU, 3) LEDs are R+G surface mount models, 4) The USB connector is now B instead of mini-B.

Børge
 
Something went wrong with my windows 10 driver for UAC2 when I changed the usb port. It would not play anything in Foobar in UAC2 mode, while UAC1 works fine. No error, just hangs, like it's being paused. Tried to perform cleanup multiple times, everything installs without any errors, but UAC2 mode just not working. Going back to previous USB port did not help either. Windows rebooted twice as well.
 
Hi, try uninstalling everything ASIO and Audio Widget related. It is my experience that the new Win10 UAC2 class driver takes priority over the ASIO device driver.

The ASIO driver isn't currently actively maintained. But it is open source, so if you wish to lend a hand, just let us know!

Børge
 
No joy yet, but here's something odd. I uninstalled and cleaned up all drivers from related to Henry Audio, and device still pops up as installed. It also works in both modes, UAC1 and UAC2, and is displayed differently Windows driver list.

UAC1: Headphones (Henry Audio USB DAC 128 MkII)
UAC2: Digital Audio Interface (Henry Audio USB DAC 128 MkII)

Not sure how this is recognized in both modes without drivers? What driver is being used to play in UAC2 mode? There is no click when switching between different sample rates, so I'm guessing it's not switching at all and plays all the time as UAC1.
 
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It seems to be that new Microsoft UAC2 driver. How do I check if it's really playing at given sample rate?
 

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Hi, It seems you have everything as it should be. Both UAC1 and UAC2 are class drivers in Windows now.

The DAC uses a code to present itself as a digital interface. The new UAC2 driver has picked up on that. Previously, the firmware used the headphone code to identify its device type. The new firmware uses digital interface for UAC1 as well. Your computer probably just cached the old code. Don't wory about that!

Cheers,
Børge
 
I've been hard at work trying to prevent audible pops!

Both DAC, driver and player are sources of potential pops. The MS UAC2 driver has been maturing significantly in that area.

When you use the bottom-right audio icon and navigate to properties and sample rates, you should be able to see all 6 in the pull-down. When you test them, the DAC uses the selected rate. That I have checked many times.

Whether or not the player sets the driver and DAC to use the music's sample rate is a different questions. Different players and protocols are better than others. In general, WASAPI exclusive tends to be rather good.

But like Dimdim says, the only way to know is to use the I2C lines.

Maybe we should add a terminal endpoint to pull debug info up without having to mount the RS232 amps. There is a HID interface in the firmware, and it should be possible to peg debug info to it. Then you'd get sample rate messages directly from the DAC firmware.


Børge
 
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If you are using Win 10 the audio player gets piped into the audio engine. That has SRC's on each in and out. Check the properties => advanced tab for the setting for the audio device. Some programs like Jriver can work around this limitation I think. However I have always had to set it manually using the Windows sound engine. The native SRC's are not the best either.