CM6631 usb audio interface .... any good ?

[Navyblue]

Originally Posted by wklie

As for Navyblue's 1st link, I can find it from taobao but there are almost no useful comments. Due to post #228, I'd recommend having the option of external power.

2nd link: my comments in post #261 are applicable.

I don't believe they are made equal due to different designs and components, and quality of soldering as many of them are hand made. I use the one in post #34 (with optional TCXO upgrade.)

Thanks.

As of now, I think the path of least resistance is the second link.

Is there a particular seller that has best/good reputation?

I don't rule out Taobao either, just haven't figure out how to make a purchase there.

[terranigma]

Originally Posted by wklie

The seller got excellent ratings. I read all the comments - there are no negative comments (taobao usually has very few negative comments, but having absolutely none is most certainly good.). All comments about the build quality are good. Most reported improved audio quality but two said it (the narrow blue version) still cannot compare with CD players.

I think, but am not 100% sure, the differences among the three are:
- The narrow green version is the oldest
- The narrow blue version is newer and has coaxial output
- The more expensive wide blue version has coaxial, optical (but the photo does not show the connector?!), I2S output and may have better components.

0.1ppm TCXO upgrade costs RMB140 extra.

Thank you for good brief. I'm actually looking for a easy customizable (reg+oscillator modifications) layout and close-to-chip I2S tapping headers. Narrow blue version seems fit for me in this perspective.

For TCXO, should I prefer replace 12Mhz one first?

[wklie]

Originally Posted by terranigma

For TCXO, should I prefer replace 12Mhz one first?

The RMB140 TCXO upgrade from this seller replaces both the 45.1584MHz and 49.152MHz only. Most of the sellers upgrade these two oscillators only (including the seller who sold my unit to me). Rarely do I see 12MHz TCXO upgrade being suggested as an option.

[Navyblue]

For this one here, I just noticed that there is no capacitor on it, but quite a few inductor.

Hi Fi CM6631A 192kHz 24bit USB 2 0 to Coaxial Optical SPDIF Convertor DAC Board | eBay

For this one, there is neither capacitor nor inductor.

24bit 192kHz USB to I2S SPDIF PCB CM6631 with Ultralow Noise 6 5UV Regulator | eBay

Can any of you more informed folks infer anything from it? Is it a good thing to be able to do without capacitor in this kind of circuit? Or is this some kind of cost cutting measure?

[Nanoloop]

I think you don't see but the parts are correct. Second choice is best.

[rade95]

Hi KlipschKid, I am trying to puzzle together your posts about diyinhk USB 192K CS6631A board and I am not sure why all your pictures have disappeared hindering this whole thread. I am trying to figure out how to make use of SPDIF out on that board because the pads are not solderable. The circuit should be there though, I think...Can somebody shed some light on this please. thanks

[rade95]

Here is the link to the board I am talking about:
Isolated 24bit 192kHz USB to I2S/SPDIF CM6631A PCB for ES9018 AK4399 PCM1794 | eBay

[KlipschKid]

I moved everything to a blog to avoid Qusp's constant irritation, and once the group buys are done, I'm off to diyhifi.

C-Media CM6631/CM6631A USB to I2S & SPDIF | myl8test

[Navyblue]

Originally Posted by rade95

Hi KlipschKid, I am trying to puzzle together your posts about diyinhk USB 192K CS6631A board and I am not sure why all your pictures have disappeared hindering this whole thread. I am trying to figure out how to make use of SPDIF out on that board because the pads are not solderable. The circuit should be there though, I think...Can somebody shed some light on this please. thanks

I messaged the ebay seller recently. According to him/her, the output is only a few mA, and is good for a Toslink module. But for a coax output extra circuitry is needed.

As for KlipschKid, I wonder if you are taxing the SPDIF output? May be something like a 6:1 transformer to step down the V and beef up the I is more appropriate here? (assuming that such suitable parts exist)

[rade95]

Originally Posted by Navyblue

I messaged the ebay seller recently. According to him/her, the output is only a few mA, and is good for a Toslink module. But for a coax output extra circuitry is needed.

As for KlipschKid, I wonder if you are taxing the SPDIF output? May be something like a 6:1 transformer to step down the V and beef up the I is more appropriate here? (assuming that such suitable parts exist)

Yep, I got the same reply from diyinhk, so I am no longer interested in trying SPDIF outputs on the board. Its not really intended to be used. Instead I will use the board for its real intended purpose: as a USB in, I2S out board @ 192KHz and as a MCLK source for the ES9018 board.