Up to my neck in a Mac

Apologies for all three of you readers. I’ve been away for so long, from the blog, but not from working. I expect to be doing more here in the future, including loading up some interesting measurement data.

But what prompted me to return was to kind of whinge, and kind of solve a problem. I’m a Windows guy, but in these days of computer audio it’s silly for me not to cover the other major platform, the Mac. So I acquired an entry level Mac Mini, plugged it into a small full HD TV, redeployed my old Apple keyboard originally used with an iPad and added a trackpad. And there you go, a fully working Mac! I can say with confidence that the so-called ease of use of Macs is wildly overstated. It’s difficult to see how one is better than the other, especially if you want to stray off the beaten path just a little.

Anyway, for Music I used a free package called Vox for a while, but then I started reviewing DACs that support Direct Stream Digital streaming and Vox didn’t support this. So after doing some research, including using the excellent The Well Tempered Computer as a resource, I decided on Audirvana Plus for the Mac. It has lots of nifty search functions, and can stream DSD, plus PCM up to 384kHz, to any DAC which supports it. The DSD uses the DoP protocols (DSD over PCM — the DSD is disguised as PCM in order to trick the USB circuitry).

But Audirvana Plus also has a cool feature called System Optimizer which gives it priority over a whole bunch of other Mac processes in order to reduced the chances of interruption. I tried to use it but got an error message, and haven’t bothered again for a few months because I was getting clean playback most of the time anyway. Last night, though, I was streaming a couple of 384kbps tracks and DSD128 ones and there were some hiccoughs. So I decided to sort out System Optimizer.

That turned out to require delving into some nasty deep Mac stuff. Ease of use, no. But I’m recording it here, in part in case I ever have to do it again.

So, it was easy to switch on in the Audirvana Plus preferences. When I double clicked on a track to play, the program told me that the Optimizer had to be installed. I said ‘Yes’ and was invited to enter my password, and then a system message appeared:

Audirvana error message

So I find the referred to folder and with the help of Mr Google managed to find out how to change permissions. But these are all rwx, nothing to do with 755. More time with Mr Google revealed a site that explained the relationship. You need to use Terminal and the chmod command. So Terminal it was. A set of cd .. commands to get me back to the root, then cd Library and then ls -l to show the contents of the folder including the permissions. There was PrivilegedHelperTools with root ownership, but in the admin (rather than wheel) group, and with the wrong sequence of r and w and xs:

Permissions 1

So it was just a matter of typing chmod 755 PrivilegedHelperTools. Simple, huh? Except that permission was refused, even though I am admin for the Mac. I think what was happening was that as this folder is a system folder not even admins can fool with it. But Mr Google helped some more. It turns out that you can force commands to happen by proclaiming yourself to be a super user. Instead of chmod 755 PrivilegedHelperTools I needed to type sudo chmod 755 PrivilegedHelperTools. I’d have to type in my password to confirm. This was accepted and the permissions were correctly set:

Permissions 2

But I also had to change the group from admin to wheel (this had probably been changed when I’d been trying to fiddle with the permissions in Finder) so: sudo chown root:wheel PrivilegedHelperTools and everything was finally right:

Permissions 3

I fired up Audirvana Plus again, switched on the System Optimizer and started playing a track. It asked for permission to install, which it did without demur and the music started playing with the SysOpt indicator showing.

So, there, Macs really are easy to use, aren’t they!

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