CM6631 usb audio interface .... any good?

You should not use ASUS firmware. The ASUS firmware is for ASUS hardware only. PM me your what OS you use and your device's VID/PID I can find right for you.

Hi,

I remember reading somewhere that 176 works with the Asus firmware and their own driver, but it doesn't work with factory firmware and driver. There are sellers who will flash the firmware with either version before they ship the device.

Julcat has his working for this:
http://www.diyaudio.com/forums/digi...b-audio-interface-any-good-3.html#post3203701

DIYINHK - what isolator IC did you choose ? Analog Devices ? Silabs ? IL ? Ti ?

cheers
 
This is the answer from the seller:
This is a product for diyer to enjoy, there are unlimited possibility.
The item description includes the I2S detail
The DAC should support the following I2S signal specification to decode each sampling rate:
*We have tested PCM1794A and it can work at 192khz 256fs(MCLK 49.152Mhz) with this PCB perfectly. There are some DAC can only decode 192khz at maximum 192fs(MCLK 36.864Mhz), user can DIY a MCLK divider or other circuit to interface with those DAC chip to decode up to 192kHz or can only stay at their lower sampling rate(MCLK)
 
I don't think the CM6631A SPDIF volume has 6dB gain. The CM6631A SPDIF out does not has volume on it. Do your board have use SPDIF IN to I2S out IC? Like DR9001 or CS8416. Maybe the 6dB gain is come from CS8416/DR9001 output fromat setting is not right for the code input.

DIYINHK - the CM6631A spdif volume has 6dB gain over CM6631 so it is distorted. The only to fix this is -6dB volume in the PC.

Can you find out if this is a firmware or driver problem please ? What can I do to fix this ? Thank you !
 
I'm not aware of a Linux driver, but maybe someone else does ?
Linux supports UAC2 async standard natively, via its ALSA drivers (included in the kernel).

Unfortunately, while it works perfectly with other UAC2 chipsets (e.g. Xmos, AudioWidget, Amanero, ecc), with this specific chip (CM6631) there seems to be some problems that needs to be fixed.

Perhaps DIYINHK may help by providing a sample card to the ALSA driver developers...
 
Julcat mentioned near the beginning of this thread that he was using a CM6331 board successfully with his Mac.

I asked the seller of the isolated CM6331A board about working with Mac OS 10.4 and he said this:
We do not have mac machine to test, somebody told it work but it should depend on the os version and system configuration.
 
I'm not aware of a Linux driver, but maybe someone else does ?


It is working fine for me with Ubuntu 12.04 and ALSA drivers. No extra software was required. Currently using it with a USB Isolator board (ADUM4160 based), output to a ES9023 home made DAC (Works equally well without the Isolator, but wished to use this and it was an easy way of introducing an external supply for the CM6631 board).

In this configuration, I do find that the DAC needs to be powered up before the PC in order for it to be detected.
 
Currently using it with a USB Isolator board (ADUM4160 based), output to a ES9023 home made DAC (Works equally well without the Isolator, but wished to use this and it was an easy way of introducing an external supply for the CM6631 board).

In this configuration, I do find that the DAC needs to be powered up before the PC in order for it to be detected.

Fantastic ! I tried this non-plug-n-play and it works with both CM6631 and 31A !

It all has to be connected and powered up before booting the PC, but it works.

Downsides :

- both 31 and 31A are limited to 48Khz or they don't work; "device does not support this sample rate".
- 31A asio driver only allows 16 bit.
- 31 driver allows all bit depths up to 32bit.

But hey, it works... :)
 
It's means your device is in full speed mode. Not in high speed mode. You should check your board design.
Fantastic ! I tried this non-plug-n-play and it works with both CM6631 and 31A !

It all has to be connected and poweured up before booting the PC, but it works.

Downsides :

- both 31 and 31A are limited to 48Khz or they don't work; "device does not support this sample rate".
- 31A asio driver only allows 16 bit.
- 31 driver allows all bit depths up to 32bit.

But hey, it works... :)
 
I know why alsa driver does not work in CM6631 device. The problem is set sampling rate time. Alsa driver set clock unit after select interface, its different with mac osx driver. if you change set clock unit before select clock unit then alsa driver can work fine.
Linux supports UAC2 async standard natively, via its ALSA drivers (included in the kernel).

Unfortunately, while it works perfectly with other UAC2 chipsets (e.g. Xmos, AudioWidget, Amanero, ecc), with this specific chip (CM6631) there seems to be some problems that needs to be fixed.

Perhaps DIYINHK may help by providing a sample card to the ALSA driver developers...
 
ADUM4160 doesn't support high-speed so of course it is full speed; the point of my post is that it CAN work in full-speed, but not plug-and-play.



Why ? What for ?
The ADUM4160 oleg
March 21, 2012 at 6:25 am · Reply
This kit is an USB isolator, not an audio device. It supports full/low USB speeds and whatever information you can transmit at these speeds, including audio.
 
I've just bought the USB to SPDIF converter in post #34 on page 4 from Weiliang's shop (not via ebay). I was told it'd use CM6631A instead of CM6631 (I've not opened up the converter to check it visually, yet). The hardware works, but I've run into some driver/firmware issues:

1. Using C-Media July 2012 drivers, foobar ASIO output via native ASIO drivers results in no sound in SPDIF. Switching to ASIO4ALL driver works though. The foobar ASIO channel map shows Headphone and Speaker but no SPDIF in the native ASIO driver (which I suspect is the reason for my problem), whereas the ASIO4ALL does have the SPDIF output in the channel map. Could somebody who has working foobar native ASIO output to SPDIF tell me what their channel map looks like?

2. 88.2kHz has no sound. I found this strange since I supposedly have the CM6631A which adds 88.2kHz and 176.4kHz to CM6631. I suspect this may be related to the firmware. Does anyone know how to check firmware version? I can only find the 2203 firmware for download. From a Chinese forum I see there is firmware 2205 and 2206 as well, but I can't find them after a lot of google.

3. I tried to install the C-Media April 2012 drivers, but it refuses to install since it cannot get past the detection of the C-Media converter. Is this because CM6631A is only supported starting from the July drivers?

Thanks in advance. Sorry for the long post.
 
Hi,
Sounds like you have a CM6631. Check the control panel - sound - properties - supported formats. Check the boxes for all the sample rates. Does this fix it ?

I enabled them but no sound at 88.2 kHz. I think that earlier in this thread you got foobar ASIO output to SPDIF working, right? Would you mind telling me what's listed in your foobar ASIO channel map? Thanks.