I think I read from somewhere about a hypothesis that suggests Asus did this in order to support 88.2kHz and 176.4kHz with CM6631.
I hope it is helping and I'm not teaching my grandmother to suck eggs !
A quick update on that case for the CM6631 - it doesn't quite fit because the oscillator is at the edge on one side, and there is a cap on the edge on the other side. So I had to grind down some of the internal guides in the case to make it fit. But in the meantime, I've lost the front plates, so I'll have to make my own, which is lots of trouble.
Anyway, the Potato 74G04 works very well - it doesn't seem to degrade the sound at all and it may even sound a bit better. Hard to say for sure without an A-B test, but for sure, it's an excellent part.
7404 G Series GHz TTL CMOS logic IC 14pin SOIC QTY-1 | eBay
Hi Klipschkid,
Looks like your having fun ,lol.itie bittie spiders smt,lol.
So have you found any sonic or improvements in the sound from these mods?
Could you do a little guide line for us to follow ,Have you changed the power supply to a shunt or CCS and tried that also?
Keep it coming,lol. THANKS!
Regards,
NS
Looks like your having fun ,lol.itie bittie spiders smt,lol.
So have you found any sonic or improvements in the sound from these mods?
Could you do a little guide line for us to follow ,Have you changed the power supply to a shunt or CCS and tried that also?
Keep it coming,lol. THANKS!
Regards,
NS
Hi Pat,
Yeah the adp151 are a little fiddly... but 9uV noise and only two 1uF smd caps required so it's worth the trouble.
The Diyinhk cm6631 use LP5900 regulators - 6.5uV noise to 100Khz, 150mA output. The board uses around 130mA. There are also several ferrite/cap filters for RF noise, so the boards are not too fussy about what power they get. However, they do pass through noise from the source so keeping that down to 100uV or so is all that's needed, and especially noise at higher freqs.
So for the 31, with usb power, I have a small rc filter for RF ( 2.2R and 100uF ) and a capacitance multiplier on the input. These drop the voltage to 3.8V from 5V but they clean up the power nicely. The ground is still dirty - PC grounds always are.
For the 31A, it has a 30uV noise linear supply with two RC filters after it so that's more than good enough for the LP5900 to be able to do its job.
Apart from the Salas shunt, I'm not particularly a fan. Shunts are wasteful and something like the TL431 has 40uV or more noise. I have used an Lm317 + TL431 for a super shunt, and it's good for analogue but too noisy for digital. Shunt or series doesn't matter - what matters are the components in the design and the circuit layout, pcb quality etc. Noise, bandwidth, output impedance, stability etc can be determined as much by choosing different transistors as can the psu topology.
The good old LM723 is still one of the lowest noise regs available - 2.5uV noise - and can be configured as a shunt or series. But it's bandwidth and output impedance are way behind the times now.
Yeah the adp151 are a little fiddly... but 9uV noise and only two 1uF smd caps required so it's worth the trouble.
The Diyinhk cm6631 use LP5900 regulators - 6.5uV noise to 100Khz, 150mA output. The board uses around 130mA. There are also several ferrite/cap filters for RF noise, so the boards are not too fussy about what power they get. However, they do pass through noise from the source so keeping that down to 100uV or so is all that's needed, and especially noise at higher freqs.
So for the 31, with usb power, I have a small rc filter for RF ( 2.2R and 100uF ) and a capacitance multiplier on the input. These drop the voltage to 3.8V from 5V but they clean up the power nicely. The ground is still dirty - PC grounds always are.
For the 31A, it has a 30uV noise linear supply with two RC filters after it so that's more than good enough for the LP5900 to be able to do its job.
Apart from the Salas shunt, I'm not particularly a fan. Shunts are wasteful and something like the TL431 has 40uV or more noise. I have used an Lm317 + TL431 for a super shunt, and it's good for analogue but too noisy for digital. Shunt or series doesn't matter - what matters are the components in the design and the circuit layout, pcb quality etc. Noise, bandwidth, output impedance, stability etc can be determined as much by choosing different transistors as can the psu topology.
The good old LM723 is still one of the lowest noise regs available - 2.5uV noise - and can be configured as a shunt or series. But it's bandwidth and output impedance are way behind the times now.
Hi
I just tested this and found my CM6631 does both I2S and SPDIF outputs at the same time.
I have finished this now - just need to re-paint the case.
An externally hosted image should be here but it was not working when we last tested it.
Hi to all,
I have one of Cm6631 usb to optical/spdif device and today its arrive. At first, I search for a driver, and one of the driver I found this topic works however, there is a issue about it. Seems like driver not fits exactly and while playing, sometimes there was a noise or "roll-of" the power seems to decreasing for one second or something.
Because of that I think maybe I try to update firmware, I downloaded FW update tool and worked on it however I think accidentally erase or damage the firmware on device. Computer doesnt recognize the device and fw update tool most of the time, 2-3 times it saw the device but while I press update, it says did but doesn't change anything. I have external power suppiler, usb cabloe for device etc. Is there anything (like re-flash firmware) I can do by myself to this device?
Thanks for your answers...
I have one of Cm6631 usb to optical/spdif device and today its arrive. At first, I search for a driver, and one of the driver I found this topic works however, there is a issue about it. Seems like driver not fits exactly and while playing, sometimes there was a noise or "roll-of" the power seems to decreasing for one second or something.
Because of that I think maybe I try to update firmware, I downloaded FW update tool and worked on it however I think accidentally erase or damage the firmware on device. Computer doesnt recognize the device and fw update tool most of the time, 2-3 times it saw the device but while I press update, it says did but doesn't change anything. I have external power suppiler, usb cabloe for device etc. Is there anything (like re-flash firmware) I can do by myself to this device?
Thanks for your answers...
Did you do the update on Windows XP? Which firmware did you try - the 2203 from nutsaudio web page? Are you sure you have CM6631 instead of CM6631A?
Since your device no longer works, perhaps you may even try flashing the Asus Xonar Essence One firmware.
If you get it to work, I'd suggest you use an external power supply (if your converter has a DC input), or use a USB 2.0 hub that requires power.
Hi,
please tell us with what driver and in what configuration (Asio, KS) have you got simultaneous output on both I2S and SPDIF
thanks
First of all, thanks for your reply...
I try to update on Windows 7 with XP mode. Still there is a green light on led however windows doesnt recognize or FW update recognize it rarely and seems there is no firmware in device but it cant write firmware.
I try 2203 from nutsaudio there was no problem, but something occurs when i try flashing Asus Xonar firmware.
I'm not sure I have CM6631, however on the case of device it was written cm6631 and when. If necessary, I can open the case and see what realy inside it.
I'm using dc input with power supply or usb 2.0 already, as I said there is green light but...
Is there any possibilty to FW updater works better on real XP than XP mode on Windows 7 ?
From what I've read, using real XP is mandatory. Emotiva even says if you use Windows 7 to flash its CM6631 product XDA-2, you'll kill it.
Thanks for your help, I found a pc with XP and I flash the firmware with nuts audio links and using nutsaudio driver it is working now.
Now, there is little problem came back, sometimes lag/interruption occurs once 2-3 minutes while playing music, using asio or wasapi doesnt change the status. I'm using headroom micro dac. Usb to microdac doesnt have this problem so it can cause only from:
CM6631 product with or without dc adapter
Hama 42971 Optical Cable ( I suspect this especially )
Hama USB A-B Cable Gold Plated Double Shielded
Or driver/firmware.
I read nearly all the topic however I can't see something like this. What can be related to this, its seems little problem but can be really annoying.
It's great to hear that you successfully revived it!
Please uninstall the nutsaudio driver and try this one:
http://emotiva.com/resources/media/xda2/Emotiva_XDA-2_Unified_Windows_USB_Driver_2012_12_12.zip
If it does not work, try this one instead:
http://www.diyinhk.com/support/U6631_U6631A-1.01_20120730.rar
In the CM6631 ASIO driver, there's a buffer setting. If you are using foobar, I think it has another buffer setting. Try increasing those buffer values.
At which sampling rate are you having these issues? If you are having problems with 44.1kHz, try 96kHz or 48kHz (enable resampling if necessary). If you have problems with 48/96/192 kHz, try 44.1kHz.
What CPU do you have on your PC? If you have a CPU weaker than Intel Core cores, it may be a problem. You may also try running DPC Latency Checker (though I've never used it) to check if your PC configuration has a problem:
DPC Latency Checker
Thanks for your all help, the problem caused from my wireless driver, it was very old (2009) and I didn't know it until using this DPC latency checker!
And also I install emotiva driver. Works perfectly!
You are great problem solver
, thanks a lot again Thanks for your all help, the problem caused from my wireless driver, it was very old (2009) and I didn't know it until using this DPC latency checker!
And also I install emotiva driver. Works perfectly!
You are great problem solver
Great! I still can't solve my own problem though. I still have not found a way to change the incorrect PID/VID in my USB-to-SPDIF converter.
Despite various versions of CM6631(A) firmware being mentioned from various forums, I have not been able to found those firmware for download, other than the nutsaudio 2203 that is not for CM6631A.I check the VID/PID numbers of my device for you and its 0x0D8C/0x0309 sorry. I don't think there is a way to change pid-vid, and I search your messages and it is different from yours. I only have 2203 firmware. Maybe you should contact other sellers on ebay or aliexpress, I think they should have some other firmwares?
An update for the Linux users out there. I just recieved my CM6631 USB/SPDIF converter.
I can confirm that with kernel 3.7.6 this board is plug and play USBAudio 2. Does 24/196 and all other common bitrate/res combinations wihout a hitch. Issues with switching bitrates from one song to the next have been resolved.
Oh, and it sounds fantastic, too. $37 no-brainer.
I can confirm that with kernel 3.7.6 this board is plug and play USBAudio 2. Does 24/196 and all other common bitrate/res combinations wihout a hitch. Issues with switching bitrates from one song to the next have been resolved.
Oh, and it sounds fantastic, too. $37 no-brainer.
What Linux are you using ? Mint ? Just curious. And do you have a 31 or a 31A ?
And yes, total no-brainer.
Yes. Mint. How did you guess?
31A
By the way, if anyone is wondering, no I am not letting ALSA do any sample rate conversion, as you can see here:
31A
By the way, if anyone is wondering, no I am not letting ALSA do any sample rate conversion, as you can see here:
Code:
paul@paul-1005HA ~ $ cat /proc/asound/card0/pcm1p/sub0/hw_params
access: RW_INTERLEAVED
format: S24_3LE
subformat: STD
channels: 2
rate: 192000 (192000/1)
period_size: 1024
buffer_size: 8192
paul@paul-1005HA ~ $ cat /proc/asound/card0/pcm1p/sub0/hw_params
access: RW_INTERLEAVED
format: S24_3LE
subformat: STD
channels: 2
rate: 88200 (88200/1)
period_size: 1024
buffer_size: 8192
paul@paul-1005HA ~ $ cat /proc/asound/card0/pcm1p/sub0/hw_params
access: RW_INTERLEAVED
format: S24_3LE
subformat: STD
channels: 2
rate: 96000 (96000/1)
period_size: 1024
buffer_size: 8192
paul@paul-1005HA ~ $ cat /proc/asound/card0/pcm1p/sub0/hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 1024
buffer_size: 8192
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