USB Card or "cleaner" for NAD M51 - needed?

[karmakuma]

I hope this has not been discussed before - search did not bring up useful information....

 

I need your help - I'm starting to get into deep and terribly unknown water.

 

I am planning on changing/upgrading my computer to something new(er), maybe back to something sophisticated/built by me instead of my current Off-The-Shelf Mac Mini.

 

I am running a NAD M51 via USB from the mentioned Computer.

 

A week or two ago I taped the 5v pin on my USB cable and confirmed to myself that the NAD M51 is properly running without the 5v line being connected to a computer. Neither for start/handshake nor playing. That is good!

 

As per Data sheet the NAD M51 is asynchronous, just as a reminder/info.

 

Now,

 

This got me thinking - I know, mostly that's dangerous ;-)

 

I can perfectly relate to the technical aspects that besides proper 5v power to a USB receiver and grounding issues there is also ripple and signal quality on the data lines to be concerned about. And, for systems depending on the senders clock accuracy, the USB Clock.

 

These aspects have been put into place by several products. Example SotM USB Card:

-Possibility of proper 5v power

-Good (assumption - type/brand unknown) USB clock

-Filters on PCI-E connection

-Filters and good regulation for used components

 

Since the NAD M51 obviously does not need 5v from the USB bus, and, since it is running in asynchronous mode, does a "specialty" USB card like SotM or PPA even improve something? If I interpreted all the schemas and design documents correctly, then I think not.

 

Same question goes for devices like iFi iUSB Power and similar. Concerning the USB cards this also extends to linear PSU or battery PSU as further optimization.

 

 

Conclusion / long story short: In respect to my setup - Computer connected to NAD M51 via USB whose 5v line has been completely blocked - do any of the well known sophisticated USB cards/addons and devices deliver better/cleaner signal or other improvements compared to simple on-board USB connections? And if so, could I ask you to explain why?

 

Thanks in advance - let's rumble ;-)

[wgscott]

I don't own one, but have had my eye on it, and had a chance to play with the C390DD. The skinny was that coax or AES input was better than USB. I've heard pro and con for HDMI (which for a mac mini or macbook pro would be ideal).

 

Also http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-spdif-converter-nad-m51-direct-digital-digital-analogue-converter-14323/

 

I have no idea about the unpowered USB, or if that would even offer an advantage. Presumably the engineers would have considered this?

[wwaldmanfan]

I don't own one, but have had my eye on it, and had a chance to play with the C390DD. The skinny was that coax or AES input was better than USB. I've heard pro and con for HDMI (which for a mac mini or macbook pro would be ideal).

 

Also http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-spdif-converter-nad-m51-direct-digital-digital-analogue-converter-14323/

 

I have no idea about the unpowered USB, or if that would even offer an advantage. Presumably the engineers would have considered this?

 

I don't believe there was a consensus on that. My M51 sounds better via USB from my MBP than through my old MF VLink-192 and Black Cat coax cable. Admittedly, I did not try the AES/EBU connection. I didn't have a cable.

I've also tried a number of USB cables, opting for the base model silver-plated copper Kimber Kable USB vs. both the more expensive 100% silver Kimber, and the Elijah Audio Isolate Cu, which has no 5v conductor.

[karmakuma]

thanks to both for your replies, tho they both miss missed my intended subject. maybe it was not written understandable or simply "tldr".

 

the point behind is not usb versus other inputs using a converter, but usefullness uf a high quality usb card/cleaner for use with an asynchronous, completely 5v decoupled dac - like the nad m51 (when physically cutting the 5v line), or other dacs if existing - when fed by a computer.

 

any ideas/knowledge around?

[Hifidelit]

Which motherboard are you referring to or do you think they are all the same?

The best way is to try it yourself, which isn't always possible I know due to cost and possible supply issues.

I'll send you a PPA card if you like and you can try it for yourself and document the differences if any on the forum - pm me.

[besturmoie]

both the more expensive 100% silver Kimber, and the Elijah Audio Isolate Cu, which has no 5v conductor.