according to the cm6631 datasheet, the output current is 8mA 3.3V,
the coax circuit has 300 ohm plus the transformer as load,
uses the famous R=V/I equation,
it's still within 8mA specification, the circuit should work
Thanks.
I tend to regard "a few" as closer to 0 than 10. UAC2 mode on Mac
I've recently found a solution for issue that caused when CM6631A module is connected to any Mac USB 2.0 ports.
When you connect module to Mac it is detected as USB Audio Class 1.0 device and you have no ability to use anything more than 48/16.
Module has a reset chip LM810M3-2.93 (http://www.nscrus.ru/content/catalog/pdf/LM810.pdf), but as we can see from the CM6631/32 datasheet, the CM6631A has a power-on self-reset.
So, reset chip has been removed from a board and now the module is always correctly detected as USB Audio Class 2.0 device on any Mac USB port.
This method has been tested on MacBook Pro, Mac Mini and this CM6631A module:
New CM6631 USB Module Assembled Board for DAC3 AD1955 DAC7 WM8741 by Weiliang | eBay
LM810M3-2.93 is a 3-pin chip located on the top of CM6631A.
I've recently found a solution for issue that caused when CM6631A module is connected to any Mac USB 2.0 ports.
When you connect module to Mac it is detected as USB Audio Class 1.0 device and you have no ability to use anything more than 48/16.
Module has a reset chip LM810M3-2.93 (http://www.nscrus.ru/content/catalog/pdf/LM810.pdf), but as we can see from the CM6631/32 datasheet, the CM6631A has a power-on self-reset.
So, reset chip has been removed from a board and now the module is always correctly detected as USB Audio Class 2.0 device on any Mac USB port.
This method has been tested on MacBook Pro, Mac Mini and this CM6631A module:
New CM6631 USB Module Assembled Board for DAC3 AD1955 DAC7 WM8741 by Weiliang | eBay
LM810M3-2.93 is a 3-pin chip located on the top of CM6631A.
Yes, you are right. XRST (reset) input of CM6631A (pin 98) is internally pulled-down and LM810 is triggering it high (3.3V) when the voltage threshold is obtained (2.93v).
So, when you remove LM810, CM6631A is doing self-reset at power on.
Yes it is 3-pin small chip marked "SA B". I've seen it at many different PCB layouts of CM6631/CM6631A and it is located near pin 98.
Hi there I'm new to the forum and am very interested in purchasing one of these units fully made up including case, so that I'm good to go from the off. I have a few questions if I may ask them please?, I have read through all the pages of the thread and noted on one of the first pages that this spdif/USB connector is considered to better the hiface evo?, can anyone confirm this please?. I am considering purchasing a hiface version 2 here in the Uk, and would appreciate any advice on sound quality compared to the afore mentioned products.
I have a MacBook Pro computer and an Audio Synthesis dax decade Dac which goes up to 48 maximum. My main ambition is to buy one of these to connect to the dac as it has no on board USB.
Any links to fully made units would be most welcome, cannot find any on eBay regarding the 6631a with inbuilt power etc.
I have a MacBook Pro computer and an Audio Synthesis dax decade Dac which goes up to 48 maximum. My main ambition is to buy one of these to connect to the dac as it has no on board USB.
Any links to fully made units would be most welcome, cannot find any on eBay regarding the 6631a with inbuilt power etc.
Would this suit my requirements please?
http://www.hifiwow.com/finished-dac...usb-to-coaxial-optical-converter-for-dac.html
And would it better the hiface Version 2?
I don't understand the difference between non - synchronous and asynchronous which is the better of the two apparently the hiface is asynchronous thanks in advance.
http://www.hifiwow.com/finished-dac...usb-to-coaxial-optical-converter-for-dac.html
And would it better the hiface Version 2?
I don't understand the difference between non - synchronous and asynchronous which is the better of the two apparently the hiface is asynchronous thanks in advance.
Last edited:
Hi
I've got one of DIYINHK's Isolated 24bit 192kHz USB to I2S/SPDIF CM6631A PCB replacing the faulty first half of an old Cambridge Audio DAC3. All is well except that anything over 96khz is very distorted. Does anyone have any suggestions? I am running windows 7 via usb2 to the four tda1541a, connected with LRCK, BCK and DATA. The original DAC was 16x oversampling, I tried removing the board with the 6 8-Bit Shift Registers but no change. There is a bonus prize for anyone who can explain what this actually did.
Many thanks in advance...
I've got one of DIYINHK's Isolated 24bit 192kHz USB to I2S/SPDIF CM6631A PCB replacing the faulty first half of an old Cambridge Audio DAC3. All is well except that anything over 96khz is very distorted. Does anyone have any suggestions? I am running windows 7 via usb2 to the four tda1541a, connected with LRCK, BCK and DATA. The original DAC was 16x oversampling, I tried removing the board with the 6 8-Bit Shift Registers but no change. There is a bonus prize for anyone who can explain what this actually did.
Many thanks in advance...
Native 24bit 192k USB to Spdif Converter 1ppm TCXO Low Jitter Version | eBay
is this one better than the $39 board?
What are people comparing these to?
Has it been compared to Audiophilleo?
Without buying one to find out for myself, I hope someone can tell me if these boards exceed the sound quality of really top notch gear, or if they are just "very good" at their price point?
is this one better than the $39 board?
What are people comparing these to?
Has it been compared to Audiophilleo?
Without buying one to find out for myself, I hope someone can tell me if these boards exceed the sound quality of really top notch gear, or if they are just "very good" at their price point?
That's the same product that I am interested in purchasing myself and would like to know the same answers if at all possible?, how good is this product in comparison to the M2Tech gear? Such as the hiface Evo?, anyone done an comparisons of these products please.
It looks exactly like the one I'm using plus other upgrades - perhaps you may read my previous posts about my unit. I don't know how it compares to other top notch gear (which is many times more expensive). Keep in mind this is a DIY product designed by somebody and handmade with a DIY soldering/build quality. If you guys decide to buy one, ask whether it comes with CM6631 or CM6631A first.
Last edited:
Thanks. I ordered the same one. But it looks like it is tough to work in that tight of a corner.
I am only interested in sound quality. I don't care about price. I have previously bought and used one of Weiliang's other boards using the TE7022 chip and I was deeply disappointed with the sound. I think this was due to bad circuit layout which attempted to save space by producing a working product on the smallest possible PCB. The one I am talking about looked like this one but did not have the DAC on board. I presume it has been discontinued for good reason. I notice when I opened the aforementioned page that firefox truncated the name, and made for an interesting commentary on the product. See the attached picture.
This looks like it is not saving space and has some "potential" for good sound. But unless someone else can highly praise the sound when compared to other highly recommended converters I will not be bothered to try it.
Attachments
Last edited:
If you want subjective sound assessment, I am afraid this forum would disappoint. And for that you have to go to computer audiophile.com. Audiophilleo and this isn't in the same price neigbourhood. If money is no object why not buy them all and send those you don't like to me.
Cost isn't the only consideration to keep PCB as small as possible.
Audiophilleo and this isn't in the same price neigbourhood. If money is no object why not buy them all and send those you don't like to me. Cost isn't the only consideration to keep PCB as small as possible.
Took 5 minutes to disassemble and remove that chip. Able to destroy & pull it off quickly with my needle-nosed plier
Just be careful not to damage other components and PCB traces.
No this forum would not disapoint. There are many good reviews on this forum.
Are you are saying there is a CM6631 review on computeraudiophile? Please provide the link.And for that you have to go to computer audiophile.com.
Exactly. You should know that sound quality has little to do with price.
If money is no object why not buy them all and send those you don't like to me.
Are you saying you would like to fill your house with second rate sounding rubbish?
In the context of the converter I mentioned above, I assume it was the primary concern, but it could also be naive design?