it seems like you already have the OEM firmware + driver if you have I2S output but you don't have the SPDIF output;
so if you want SPDIF out you must flash the firmware + driver supplied for Asus Essence One (that includes this CM6631 chipset)
the link is here and you must select your OS (operating system) before
SUPPORT
in firmware section the first one is the firmware update tool and there you have also the newest firmware
you'll need to install the new firmware and also the new asus driver to support SPDIF; anytime you want to convert back to OEM version (I2S but without SPDIF) then you must flash the OEM firmware + OEM driver from that link I provided earlier (nutsaudio)
so if you want SPDIF out you must flash the firmware + driver supplied for Asus Essence One (that includes this CM6631 chipset)
the link is here and you must select your OS (operating system) before
SUPPORT
in firmware section the first one is the firmware update tool and there you have also the newest firmware
you'll need to install the new firmware and also the new asus driver to support SPDIF; anytime you want to convert back to OEM version (I2S but without SPDIF) then you must flash the OEM firmware + OEM driver from that link I provided earlier (nutsaudio)
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Hi wklie:
You can't use the version of firmware. The firmware is for CM6631 chip not for CM6631A chip. If you update this firmware to your device, you device will not function any more. You should find the firmware for USB-to-SPDIF. The VID/PID should be 0x0D8C/0x0319.
You can't use the version of firmware. The firmware is for CM6631 chip not for CM6631A chip. If you update this firmware to your device, you device will not function any more. You should find the firmware for USB-to-SPDIF. The VID/PID should be 0x0D8C/0x0319.
Tsai - I just want to say thanks for contributing to this thread. Do you mind me asking how you know the full range of product ids etc ? C-Media don't seem to like to give out much info, and I'd really like to know more about the differences between the 31 and 31A.
For example, the 31A seems to need a USB ground connection at start up but after that the ground can be disconnected and it can have fully independent power. But the 31 doesn't seem to need this. I wonder why....
thanks
For example, the 31A seems to need a USB ground connection at start up but after that the ground can be disconnected and it can have fully independent power. But the 31 doesn't seem to need this. I wonder why....
thanks
Hi KlipschKid:
The major different of CM6631A and CM6631 is sample rate support. CM6631A support 176.4K sample rate in IIS mode but CM6631 do not support it. Other feature is the same.
The major different of CM6631A and CM6631 is sample rate support. CM6631A support 176.4K sample rate in IIS mode but CM6631 do not support it. Other feature is the same.
If anyone has bought a cm6631a for synch with ES9018, the board has simple pin headers but regular cable degrades the signal, and there's no u.fl pad. So I have made a u.fl cable to fit. It's not that easy to do - I cut the skin off slowly with a very harp craft knife and then scraped the shield wire back to expose the core cable. Then I wrapped sole solid core copper from cat6 cable around the shield. I found it quite fiddly but it's done and works.
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.
Hello all,
I have been lurking here and really appreciate all the info so far.
I have ordered a board from China with the CM6631A on it. I assume it will have the Asus firmware on it because it is equipped with coax and optical SPDIF.
I have also ordered a DAC from China which is based on WM8740 and DIR9001. The WM8740 can do 192/24, but the DIR9001 is limited to 96/24, so I do not necessarily want to use the SPDIF between the two boards.
My question: Could I bypass the DIR9001 by simply flashing my CM6631A to the OEM (I2S) firmware and then use fine wires to connect the 4 I2S (out) pins on the CM6631 to the 4 I2S (in) pins of the WM8740 chip on the DAC board?
Has anyone ever "daisy-chained" between boards like this to bypass DIR9001 and/or SPDIF?
I have been lurking here and really appreciate all the info so far.
I have ordered a board from China with the CM6631A on it. I assume it will have the Asus firmware on it because it is equipped with coax and optical SPDIF.
I have also ordered a DAC from China which is based on WM8740 and DIR9001. The WM8740 can do 192/24, but the DIR9001 is limited to 96/24, so I do not necessarily want to use the SPDIF between the two boards.
My question: Could I bypass the DIR9001 by simply flashing my CM6631A to the OEM (I2S) firmware and then use fine wires to connect the 4 I2S (out) pins on the CM6631 to the 4 I2S (in) pins of the WM8740 chip on the DAC board?
Has anyone ever "daisy-chained" between boards like this to bypass DIR9001 and/or SPDIF?
The DAC board looks hackable - the chips seem to be soic so that's not so bad if you have experience with smt and a reasonably good iron with a fine tip. The CM board looks close to impossible. You'll need top notch skills.
This CM board has spdif and I2S :
24bit 192kHz USB to I2S SPDIF PCB CM6631 Ultralow Noise 6 5UV Regulator Woptical | eBay
I can't find any half-decent pre-built I2S-input DACs on Ebay. Do you know AMB ? AMB does the y2 dac but it also has smt chips to do. It is WM8741 and I2S input.
http://www.amb.org/audio/gamma2/
I made one with CM :
http://www.flickr.com/photos/30303503@N06/8295460283/sizes/c/in/photostream/
I sell it to you if want but it's worth more than the Ebay stuff I'm afraid. I have another y2 with no cm already built too. Too many DACs eh ?
This CM board has spdif and I2S :
24bit 192kHz USB to I2S SPDIF PCB CM6631 Ultralow Noise 6 5UV Regulator Woptical | eBay
I can't find any half-decent pre-built I2S-input DACs on Ebay. Do you know AMB ? AMB does the y2 dac but it also has smt chips to do. It is WM8741 and I2S input.
http://www.amb.org/audio/gamma2/
I made one with CM :
http://www.flickr.com/photos/30303503@N06/8295460283/sizes/c/in/photostream/
I sell it to you if want but it's worth more than the Ebay stuff I'm afraid. I have another y2 with no cm already built too. Too many DACs eh ?
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Thanks for the links!
Alas, I have already purchased the two boards, with the original intent of simply using coax SPDIF and limiting my source material to <=96k (and/or living with soft resampling of the higher res stuff).
I already have a TE7022-based USB-SPDIF unit which sounds great but lacks 88.2k, which bugs me because I am getting more and more music at 88.2. I also already have a nice WM8524-based DAC. I also like it, but I suspect I will like the 8740 better, especially since I also have some nice opamps on the way as well.
For the prices, it'll be all fun to play with. I'll start with just using coax SPDIF until I figure out what all sounds good to me, then build it into an enclosure and either solder the SPIDF interfaces together or try to link I2S between the two. Even if I break a board (or both) it won't be the end of the world.
Alas, I have already purchased the two boards, with the original intent of simply using coax SPDIF and limiting my source material to <=96k (and/or living with soft resampling of the higher res stuff).
I already have a TE7022-based USB-SPDIF unit which sounds great but lacks 88.2k, which bugs me because I am getting more and more music at 88.2. I also already have a nice WM8524-based DAC. I also like it, but I suspect I will like the 8740 better, especially since I also have some nice opamps on the way as well.
For the prices, it'll be all fun to play with. I'll start with just using coax SPDIF until I figure out what all sounds good to me, then build it into an enclosure and either solder the SPIDF interfaces together or try to link I2S between the two. Even if I break a board (or both) it won't be the end of the world.
Those DAC boards usually have four resistors on the i2s lines, it would be easy to remove them and add a header instead, that would give you an easy 'tap' into the i2s feed on the DAC board. The other I'm not sure about - I've been lurking around on this thread trying to decide on the best option for me!
Good idea. I wonder if a header is really necessary, though. Convenient, for sure - but perhaps it is feasible to tap directly onto the chip pins.
Can anyone tell me how flexible/pliable those chip pins might be? Could they be carefully released from the board and bent upwards and slightly away from each other to allow easier access to solder some fine wire on them? Or, are they so brittle/delicate that they will simply snap off the chip?
Can anyone tell me how flexible/pliable those chip pins might be? Could they be carefully released from the board and bent upwards and slightly away from each other to allow easier access to solder some fine wire on them? Or, are they so brittle/delicate that they will simply snap off the chip?
I've been mapping things out and I think I have a plan.
On the DAC board, there are already connections between the DIR9001 I2S-out pins (4, 10, 11 and 12) and the WM8740 I2S-in pins (1, 2, 3 and 5). I am thinking I will disconnect the DIR9001 pins (4, 10, 11 and 12) and use those board contacts as a connection point to the WM8740. Perhaps I could even install makeshift headers there with some header pins harvested from an old sound card or video card.
On the CM6631 board, it appears that my only choice will be to solder directly onto pins 89, 93, 94 and 95. The good news is it appears (from the e-bay photos) that these pins are not currently connected to anything (electrically) on this board so there will be no real need to disconnect them from the board physically other than to maybe enable easier soldering (see my questions above).
If I am going to go to all this trouble (eventually, maybe) I should probably go ahead and terminate the far end of the tether wire with female header connectors so I can plug n' play it to the makeshift header pins on the DAC board (if I can successfully install them).
I am thinking CAT-5E might be a good choice for the wiring (?) and I will have to get a new soldering iron (I need a new/better one anyway).
Am I overthinking this? Underthinking it?
On the DAC board, there are already connections between the DIR9001 I2S-out pins (4, 10, 11 and 12) and the WM8740 I2S-in pins (1, 2, 3 and 5). I am thinking I will disconnect the DIR9001 pins (4, 10, 11 and 12) and use those board contacts as a connection point to the WM8740. Perhaps I could even install makeshift headers there with some header pins harvested from an old sound card or video card.
On the CM6631 board, it appears that my only choice will be to solder directly onto pins 89, 93, 94 and 95. The good news is it appears (from the e-bay photos) that these pins are not currently connected to anything (electrically) on this board so there will be no real need to disconnect them from the board physically other than to maybe enable easier soldering (see my questions above).
If I am going to go to all this trouble (eventually, maybe) I should probably go ahead and terminate the far end of the tether wire with female header connectors so I can plug n' play it to the makeshift header pins on the DAC board (if I can successfully install them).
I am thinking CAT-5E might be a good choice for the wiring (?) and I will have to get a new soldering iron (I need a new/better one anyway).
Am I overthinking this? Underthinking it?
It appears that this sort of thing certainly can be done:
I like a challenge, I am good with my hands, and I have lots of old computer parts to practice on...
An externally hosted image should be here but it was not working when we last tested it.
I like a challenge, I am good with my hands, and I have lots of old computer parts to practice on...
Hi,
When you get the DAC, please start a new thread about it, or perhaps you might find a thread already.
The CM6631 wont driver long (over 10cm) i2s lines very well because of the capacitance loading, and the signal quality will be degraded the longer the line - you'd really need to add a quad line driver (74vhc04) if you want this to be better than spdif. You also need to consider ground returns for the i2s signals, because if each signal wants to have current flow, it needs a return path immediately next to it for the return current. So use ribbon or cat cable with the grounds connected locally to the signals. If you don't do this you add inductance and again, degrade the signal. You din't mention the ground returns at all in your plan - no return = no flow = no sound.
It seems to me you've bought the wrong CM for what you want to do, and I'd suggest you might think first about optimising the DACs performance and the spdif circuit, and then, when the DAC is as good as it can be, think about whether i2s is even needed. The DAC might sound lousy due to poor routing, grounding, etc, and changing from spdif to i2s will yield precisely zero benefit.
Anyway, have fun - I think that's really why you've bought them right ?
When you get the DAC, please start a new thread about it, or perhaps you might find a thread already.
The CM6631 wont driver long (over 10cm) i2s lines very well because of the capacitance loading, and the signal quality will be degraded the longer the line - you'd really need to add a quad line driver (74vhc04) if you want this to be better than spdif. You also need to consider ground returns for the i2s signals, because if each signal wants to have current flow, it needs a return path immediately next to it for the return current. So use ribbon or cat cable with the grounds connected locally to the signals. If you don't do this you add inductance and again, degrade the signal. You din't mention the ground returns at all in your plan - no return = no flow = no sound.
It seems to me you've bought the wrong CM for what you want to do, and I'd suggest you might think first about optimising the DACs performance and the spdif circuit, and then, when the DAC is as good as it can be, think about whether i2s is even needed. The DAC might sound lousy due to poor routing, grounding, etc, and changing from spdif to i2s will yield precisely zero benefit.
Anyway, have fun - I think that's really why you've bought them right ?
Here's photo of the current state of the CM6631 I'm hacking. I tried an adum3440 isolator but it seemed worse. So I pulled that off and now I'm going to use a Potato Chips 74G04 and a cat socket so I can use cat cable to connect into my DAC.
It isn't finished - trying to find some time to do that this week.....
It isn't finished - trying to find some time to do that this week.....
An externally hosted image should be here but it was not working when we last tested it.
Okay, so, I decided to get it finished. I used an adp151 to power the 74G04 because the LP5900 is already loaded near its limit. The LAN socket allows gsgsgsgsg connections. I used 62R as termination resistors.
I blacked out a section of the photo as a courtesy to the seller, who wants to keep the routing in that area a secret.
The last thing to do is case it, and I'll fit a BNC socket for the spdif output. It'll fit very well in one of these :
1455C801 - HAMMOND - ENCLOSURE, ALUMINIUM END PLATE | Farnell United Kingdom
I blacked out a section of the photo as a courtesy to the seller, who wants to keep the routing in that area a secret.
An externally hosted image should be here but it was not working when we last tested it.
The last thing to do is case it, and I'll fit a BNC socket for the spdif output. It'll fit very well in one of these :
1455C801 - HAMMOND - ENCLOSURE, ALUMINIUM END PLATE | Farnell United Kingdom
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Hi, this is the "old" CM6631 pcb ? not the "A" version?
I see that you mounted an RJ45 for I2S output but you also consider BNC for the coax output, so have you find some way to have available both of the outputs simultaneously?
I don't understand why CM decided to have only 1 of the outputs available at a time, although I don't quite understand the ASUS Essence One construction either, where supposedly their firmware and driver which enables only SPDIF and mutes I2S would have to feed also the DAC present in that soundcard...so that means that the internal DAC isn't receiving I2S from the CM6631? they went with SPDIF all the way including internal DAC?
too bad there ain't any users around here with such a soundcard, it might be interesting to find out their solution by opening the box
I see that you mounted an RJ45 for I2S output but you also consider BNC for the coax output, so have you find some way to have available both of the outputs simultaneously?
I don't understand why CM decided to have only 1 of the outputs available at a time, although I don't quite understand the ASUS Essence One construction either, where supposedly their firmware and driver which enables only SPDIF and mutes I2S would have to feed also the DAC present in that soundcard...so that means that the internal DAC isn't receiving I2S from the CM6631? they went with SPDIF all the way including internal DAC?
too bad there ain't any users around here with such a soundcard, it might be interesting to find out their solution by opening the box