Hi, I saw that you modded the pcb and made a coaxial digital out using also a pulse transformer; but in an older posting of yours you said that this driver enables only I2S and not SPDIF on the pcb; so my queston is, why have you even bothered to add SPDIF out if the driver doesn't support it?
also, have you tried using ASIO in Foobar for example?
is this board really supporting ASIO drivers?
thanks
I use Foobar and either the asio driver or wasapi component. The first time I tried the spdif with asio, it didn't work, so I used wasapi, but this weekend spdif worked through the asio driver too. I have no idea why, probably user error ;-)
I am currently using it with a new dac I got on Taobao - a dual ad1955 384khz asrc dac.
USB SPDIF PCM2706Ë«AD1955 384kHz ASRC ÉýƵ DAC ½âÂëÆ÷ Ì×¼þ-ÌÔ±¦Íø
As you can see, I removed the usb socket from the CM6631 and filtered the power input, as above post 46. I haven't got around to fitting BNCs etc.
An externally hosted image should be here but it was not working when we last tested it.
Sorry the photo is blurred (forgot to stop down for more dof) but it's just a quick show and tell.
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thanks for your answer and for the picture - what a cool dac you have there 
but how do you switch between ASIO and WASAPI? you have to uninstall one driver and put the other one instead?
I saw the ASIO driver download link, but where can be found the wasapi one?
also, have you tried the ASUS firmware for essence one?
but how do you switch between ASIO and WASAPI? you have to uninstall one driver and put the other one instead?
I saw the ASIO driver download link, but where can be found the wasapi one?
also, have you tried the ASUS firmware for essence one?
First download wasapi here (for win7 and vista):
foobar2000: Components Repository - WASAPI output support
after installing it, go to Foobar's file_preferences_playback_output and select the Device from the drop down at the top of the box. It should show wasapi devices as well as DS.
For asio, again install the asio driver (and connect cm6631) and go to file_preferences_playback_output_asio virtual devices and click on add new. You should get "asio for c-media device". After that, click on it and then click on edit, to make sure you have the channels set up, bit depth, and latency.
Then you should be ready to switch between ds, wasapi and asio. You might need to go into windows sound control panel and edit the c-media device so it accepts all frequencies and can also be given priority (for wasapi to work).
There's quite a lot of help pages about this - google is your friend if you get stuck.
cheers
foobar2000: Components Repository - WASAPI output support
after installing it, go to Foobar's file_preferences_playback_output and select the Device from the drop down at the top of the box. It should show wasapi devices as well as DS.
For asio, again install the asio driver (and connect cm6631) and go to file_preferences_playback_output_asio virtual devices and click on add new. You should get "asio for c-media device". After that, click on it and then click on edit, to make sure you have the channels set up, bit depth, and latency.
Then you should be ready to switch between ds, wasapi and asio. You might need to go into windows sound control panel and edit the c-media device so it accepts all frequencies and can also be given priority (for wasapi to work).
There's quite a lot of help pages about this - google is your friend if you get stuck.
cheers
thanks for all your kind explanation and sorry for bothering that much but I needed to decide which board I will buy cause there are already a few options around, but all of them have their ups and downs and none of them being mature enough to satisfy all the needs alone, without adding to it recklockers,Buffers, FIFOs, etc.
for those who received the board from the seller with ASUS firmware (so that you have only SPDIF enabled without capability to use I2S) here is the firmware which you could update on the device:
Need to be flashed by WINXP only
http://www.nutsaudio.com/driver/CM6631_Firmware.zip
and after that you can install C-Media ASIO driver from here (for all Win)
http://www.nutsaudio.com/driver/CM6631_Driver.zip
Need to be flashed by WINXP only
http://www.nutsaudio.com/driver/CM6631_Firmware.zip
and after that you can install C-Media ASIO driver from here (for all Win)
http://www.nutsaudio.com/driver/CM6631_Driver.zip
who doesn't need the I2S and outputs to DAC board only via SPDIF and wants to have all the sample rates in one bundle (including 88 khz and 176 khz) might try to update their generic CM6631 with ASUS essence one firmware + driver from here :
ASUS - Multimedia- ASUS Xonar Essence One
(just need to select the OS and there you go)
ASUS - Multimedia- ASUS Xonar Essence One
(just need to select the OS and there you go)
Hi DIYINHK!
I purchased your CM6631 usb-ddc and several Japanese Audiophiles are now trying to connect their DACs. I'm looking forward the arrival of the device.
Is it possible to use this device with Linux e.g. Voyage MPD? According to one of the most famous Audio DIY-BBS in Japan, this device can be recognized with Linux with ALSA1.0.23, kernel 2.6.35 or later, however the sound was gradually 'choppy' (=in fragment; spdif) then system (driver?) was frozen.
Could you check and let us know about detail information about Linux?
Regards,
I purchased your CM6631 usb-ddc and several Japanese Audiophiles are now trying to connect their DACs. I'm looking forward the arrival of the device.
Is it possible to use this device with Linux e.g. Voyage MPD? According to one of the most famous Audio DIY-BBS in Japan, this device can be recognized with Linux with ALSA1.0.23, kernel 2.6.35 or later, however the sound was gradually 'choppy' (=in fragment; spdif) then system (driver?) was frozen.
Could you check and let us know about detail information about Linux?
Regards,
Thank you for interesting in our product!
The 29.95 version pcb is target for highest price to performance ratio, it uses 15ppm NDK crystal from digikey, 50ppm KDS oscillator from shenzhen
We will have an galvanized isolation version with dual ultralow noise regulator and 15ppm NDK crystal+25ppm FOX oscillator all from digikey. It's target for the most demand Audiophiles
The SPDIF is a standard signal specification, the frozen problem should related to the software player. I recommed use I2S directly rather than SPDIF, all DAC convert SPDIF back to I2S to decode. It avoid one more unnecessary layer.
The 29.95 version pcb is target for highest price to performance ratio, it uses 15ppm NDK crystal from digikey, 50ppm KDS oscillator from shenzhen
We will have an galvanized isolation version with dual ultralow noise regulator and 15ppm NDK crystal+25ppm FOX oscillator all from digikey. It's target for the most demand Audiophiles
The SPDIF is a standard signal specification, the frozen problem should related to the software player. I recommed use I2S directly rather than SPDIF, all DAC convert SPDIF back to I2S to decode. It avoid one more unnecessary layer.
Hi,
I finally finished the CM6631 + AMB y2 build so here are some pics. I can switch between USB and external power so it can get clean power from a linear psu. In which case noise can only enter through the USB D+/- lines, so I'm not sure I will need to add an adum3440 isolator. However, there is space to try one, so, maybe.
Anyway, it sounds good and the linear psu really helps. USB power is not as good - usb power has noticeably more mushy treble and harsh vocals, with less bass definition.
And with a 30V Mini3
I finally finished the CM6631 + AMB y2 build so here are some pics. I can switch between USB and external power so it can get clean power from a linear psu. In which case noise can only enter through the USB D+/- lines, so I'm not sure I will need to add an adum3440 isolator. However, there is space to try one, so, maybe.
Anyway, it sounds good and the linear psu really helps. USB power is not as good - usb power has noticeably more mushy treble and harsh vocals, with less bass definition.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And with a 30V Mini3
An externally hosted image should be here but it was not working when we last tested it.
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Hi, pls explain why have you chosen this particular adum chip? I see from the datasheet that is a highspeed multichannel isolator but it is not designed specially for USB isolation; why am I telling this? because looking to the ADuM4160 datasheet that was specially made for USB data (D+ and D-) data isolation, it is stated that
"USB lines must automatically switch between actively driving D+/D−, receiving data, and allowing external resistors to set the idle state of the bus. The ADuM4160 provides mechanisms for detecting the direction of data flow and control over the state of the output buffers. Data direction is determined on a packet-by-packet basis"
do you think your current chip behaves in the same way?
I am curious about your results with this chip, and judging by the datasheet is being able to support 150 Mbs (in contrast with the adum4160 that can support only 12 mb thus limited to only 24bit/96khz) so that means it could easily handle even 32 bit 352 khz sampling rates over I2S.
keep us updated pls if you succeeded and also with the sound impressions after the isolation, thanks
"USB lines must automatically switch between actively driving D+/D−, receiving data, and allowing external resistors to set the idle state of the bus. The ADuM4160 provides mechanisms for detecting the direction of data flow and control over the state of the output buffers. Data direction is determined on a packet-by-packet basis"
do you think your current chip behaves in the same way?
I am curious about your results with this chip, and judging by the datasheet is being able to support 150 Mbs (in contrast with the adum4160 that can support only 12 mb thus limited to only 24bit/96khz) so that means it could easily handle even 32 bit 352 khz sampling rates over I2S.
keep us updated pls if you succeeded and also with the sound impressions after the isolation, thanks
Merry Christmas !
I plan to use on the I2S - but I could try it is on the usb lines, perhaps just to confirm it doesn't work. The 3440 does bi-directional flow according to the datasheet, but I don't know enough about usb protocols to know if this is enough. Probably not, but there's no harm trying.
I plan to use on the I2S - but I could try it is on the usb lines, perhaps just to confirm it doesn't work. The 3440 does bi-directional flow according to the datasheet, but I don't know enough about usb protocols to know if this is enough. Probably not, but there's no harm trying.
Merry Christmas for you too!
for I2S isolation better choice would have been the quadruple ISO7240 which has only 1ns eye pattern skew jitter declared for the 150 Mbs speed, or high speed cmos optocouplers like HCPL-7723 which have only 2ps jitter;
the ideea is not to add more jitter than you would achieve without isolation, better said not to do more harm than good
for I2S isolation better choice would have been the quadruple ISO7240 which has only 1ns eye pattern skew jitter declared for the 150 Mbs speed, or high speed cmos optocouplers like HCPL-7723 which have only 2ps jitter;
the ideea is not to add more jitter than you would achieve without isolation, better said not to do more harm than good
7240C has noise filter but is only 25Mbps; 7240M does not have noise filter but is 150Mbps. There doesn't seem to be one that does both noise filtering and 150Mbps ? Optocouplers have issues apparently - never tried them myself. I have used adum4160, and heard the improvement so I know AD's isolators do the job.