Newbie question RE Mac USB bus

[RickDastardly]

Hi All,

 

This is my first post here. I've been a lurker for a few weeks since discovering this great site in my quest to build my Mac Mini music server.

 

I am currently using an Arcam rDAC which is hooked up to my 2011 Mac Mini via USB. I've auditioned Pure Music and I am now trying out Audirvana. I am aware that it is important to ensure that no other USB devices are connected. I have moved away from using a USB-connected external hard-drive and am instead using firewire. I also understand that it is important to turn off the IR controller too. I noticed that the Audirvana User Manual mentions that the DAC should be listed alone under a High speed USB bus section. I am currently using a bluetooth keyboard, but see the following in the system preferences for USB:

 

(hope that screenshot works ok)

 

The DAC does not appear to be "alone" but appears together with the Bluetooth USB host controller. Is this going to have a detrimental impact?

[jhwalker]

Hi All,

 

This is my first post here. I've been a lurker for a few weeks since discovering this great site in my quest to build my Mac Mini music server.

 

I am currently using an Arcam rDAC which is hooked up to my 2011 Mac Mini via USB. I've auditioned Pure Music and I am now trying out Audirvana. I am aware that it is important to ensure that no other USB devices are connected. I have moved away from using a USB-connected external hard-drive and am instead using firewire. I also understand that it is important to turn off the IR controller too. I noticed that the Audirvana User Manual mentions that the DAC should be listed alone under a High speed USB bus section. I am currently using a bluetooth keyboard, but see the following in the system preferences for USB:

 

[ATTACH=CONFIG]282[/ATTACH]

(hope that screenshot works ok)

 

The DAC does not appear to be "alone" but appears together with the Bluetooth USB host controller. Is this going to have a detrimental impact?

 

As far as I can tell, the Mac Mini's automagically reallocate which devices are on which bus dynamically. No matter which slot I use for my USB DAC, either the Bluetooth or IR is on the same bus

 

You'd think with only three devices and four slots, I'd be able to get it by itself in at least one of the combinations!

 

That said, I didn't think it really mattered until I started hearing some strange, digital distortion in the sound coming from my USB DAC - only via USB, not optical. After checking in with technical support, they suggested I move the DAC to a different USB port - problem solved.

 

So I'd just move it from one slot to the other until you don't have any problems Not a very satisfying answer, but speaking from my experience.

[RickDastardly]

Thanks for your reply John.

 

I think I am using the USB port that most recommend on the MAC mini for connecting a DAC. Luckily I haven't really noticed any digital distortion, but I shall keep your advice in mind and try different USB ports if it ever becomes a problem.

[Melvin]

Hey Richard .. when I got my current DAC I did the same and tried various ports til it was listed alone under said high speed bus. Unfortunately I experienced a problem similar to John although mine was intermittent. I switched to another port as Jason at Schiit suggested and all was well. I can't detect any degradation in sound using this port. YMMV. Good luck.

[jhwalker]

Hey Richard .. when I got my current DAC I did the same and tried various ports til it was listed alone under said high speed bus. Unfortunately I experienced a problem similar to John although mine was intermittent. I switched to another port as Jason at Schiit suggested and all was well. I can't detect any degradation in sound using this port. YMMV. Good luck.

 

You may have noted I have the Bifrost, as well and Jason suggested the same to me. In my case, it was the 1st port on the left (if viewing the Mac Mini from the rear) that was causing the intermittent distortion - moving to the next slot (e.g., the 2nd from the left) solved the problem.

[mwheelerk]

Interesting, I wonder if my problem could be USB port related. I am having problems with one of my external HDD just intermittently self ejecting.

[Melvin]

You may have noted I have the Bifrost, as well and Jason suggested the same to me. In my case, it was the 1st port on the left (if viewing the Mac Mini from the rear) that was causing the intermittent distortion - moving to the next slot (e.g., the 2nd from the left) solved the problem.

 

I did notice you have the Bifrost and my problem involved the same port!

[RickDastardly]

Thanks for all of your replies on the subject.

 

I am currently demoing Audirvana Plus having just finished the 15 day Pure Music trial. I certainly prefer the interface of Audirvana, but I'm not quite sure if it is sounding just quite as good as Pure Music did (but that may well be the difference in price tag that is influencing my opinion sub-consciously). I notice that some of you are using Audirvana and some Pure Music. Out of interest, what are your opinions of them (sound quality, updates, support, issues etc.) I will also look for thread that covers this topic too, as I'm sure there is one ;-)

 

Thanks again.

Rich

[mayhem13]

Hey Rich. You probobly won't get a solid answer on the subject as of course the response will be an opinion. There's no empirical 'improvement' to the sound, just 'different, as these various software add ons an plug ins use algorithmic DSP. My viewpoint is to use the front end/plug in whose user features you prefer and who may have the better customer/ tech supporter.......if you can justify the cost for the added functionality, of any. Glad to see you determined the best BUS to use. Makes you wonder if the advantages of reduced Jitter via USB is worth the potential trade offs. While I can't discern a difference between USB and Optical or Coax, I have not experienced any of the USB noise issues mentioned above either. I have had intermittent failures of USB buses on just about every machine I've ever owned though but the music or attached device just stops....no audible distortions of any kind so I stick with the USB.

[John_Foxx_Fan]

Sorry to bump an old thread but I have a similar issue with an old c2d Mac Mini.

 

In order to get Integer mode to work on Pure Music I have to keep on swapping the usb port over.

 

I have a Audiophilleo2 connected to a Rega Dac. On a fresh boot if I don't move over to a new USB port I get static with Integer mode. Once I change over to a new port it cures itself.

 

Any suggestions?