MacMini 2014 and High Sierra as a test bed music server!

[OneNoteSam]

Hi Bob,

Thanks for a very informative post! I was not happy with the sound coming from my Mac Mini High Sierra, running iTunes with Bitperfect, so I started to look around  for possible improvements. I discovered this forum and a wealth of information here, and your post was pretty much spot on what I was looking for.

 

As I live in Europe, availabilty and cost of equipment is somewhat different from the US so in my optimization journey I will likely go a slightly different route. Will post the results as I go along. Hope this will help others too.

 

Optimizations so far:

Replaced Bitperfect with Audirvana+:Noticable improvement in clarity and resolution. And most important, totally stable. BitPerfect with iTunes was not.

 

Optimized OS as per http://www.co-bw.com/Audio_OSX_Optimal_Audio.htm:

Note this is written for earlier OS, so did  what I could in High Sierra. This gave a subtle improvement in clarity.

 

So far the MM is not touching my analog reference, but the two steps above helped significantly.

 

This is my first post here, so I posted my system details below. 

 

All the best,

Svein 

 

Current system:

Digital: GTech external FW drive - MM 2014, 8GB, 500GB HDD, High Sierra - Audioquest USB Carbon - Bel Canto Dac 1.7 - Nordost Heimdall - Lavardin IS ReferenceLavardin Speaker Cable - Harbeth 30.1

 

Analog reference:

Linn LP12 (Radikal, Ittok IV II, Adikt) - Linn Tonearm Cable - Lejonclou Slipstik - Nordost Heimdall - Lavardin IS Ref

 

Other:

Isotek EVO3 power conditioner (for all audio, incl MM), Nordost, Audioquest and OEM power cables

[OneNoteSam]

Thanks Bob, 

I continued my process by adding the Intona USB isolator and running OS from an SDXC card as done by a number of others. I also tuned Audirvana according to the recommendations in this post. Overall the Mac Mini now sounds much better, for a not too significant cost. 

 

 

 

Some notes that may be of use to others:

- The Intona USB isolator make a significant difference. I previously used two Audioquest Jitterbugs, but the Intona is in a different class. More relaxed sound and less listening fatigue. Everything sounds tighter and more accurate, and I find myself listening at higher volume. I kept one of the Jitterbugs in an unused USB port on the Mac Mini. The Jitterbug gave the system a slightly rounder bass. I do not know if this is more accurate, but I prefer this so far. Running a Jitterbug before the Intona did not work well. The Intona is sensitive to cable quality both on the inlet and outlet side. I tried with an old Apogee USB cable on the inlet first and was somewhat underwhelmed. I then changed to the same Audioquest Carbon I had on the outlet, and this made a significant improvement. 

 

- Running the OS from the SDXC card gave some improvement, but less significant than the Intona. This was a bit tricky to do in High Sierra, as formatting the card and installing OS was not straightforward (Setting the partition table to GUID require you to format the parent of the card in Disk Utility. There is also some conflicting information on how to install OS on the card on Apple support pages. I found downloading OS to the hard drive and then select do the install on the card in the "Installer MacOS High Sierra" tool worked, not the procedure suggested by Apple here https://support.apple.com/en-us/HT201372)

 

- Optimising Audirvana izotope settings gave further improvements, although not as significant as adding the Intona. I posted in the thread referenced above my settings.

 

Next step is to install an internal 1TB SSD and move my library there...

 

Svein 

[OneNoteSam]

Completed the process above, installed a 1TB SSD in place of the FW hard drive (powered by a wall wart...)  - a breeze thanks to the iFixit tools and instructions. Further improvement. I am enjoying the sound of digital much more now - and find myself listening at higher volume settings.

 

Other tweaks:

- all audio, including computer is powered from the Isotek EVO3

- use of the Apple Firewire to Ethernet adapter to connect to the internet, rather than the built in plug

- upgraded the power cable to my amp and DAC. Especially the amp power cable was a noticeable improvement.

- I have two versions of OS on the computer, a slim version on the SDXC card, and a full version on its own small partition on the 1 TB SSD. Convenient if I want to run other applications than Audirvana. 

 

So conclusions (which should not come as a surprise to anyone at this site)

- To release the potential of the MacMini as a music server, cleaning up the USB is a required step

- Removal of spinning drives help the sound

- optimising OS by simplifying the OS and splitting OS and audio files help the sound

- Refinement of the power system (including the computer) yield a significant sound improvement

 

Thanks to bobfa for starting this thread and sharing his experience. 

 

Svein

 

 

[OneNoteSam]

Intona USB isolator - 289 EUR

Audirvana  - 74 USD

1 TB SSD - 2592 NOK

SDXC Card - 1290 NOK

iFixit kit - 25 USD

Audioquest Carbon USB cable - USD 50 (I needed an additional length for the Intona, already had one).  

 

Total about 890 USD. I think the SSD and SDXC can be had cheaper in the US, but I live in Europe. Upgrading the SSD of the MM may be argued as a necessity anyway, as the machine is 4 years old. 

 

The Intona provides galvanic isolation, yes. Check their webpage for more information. The Mac Mini is clocked from the DAC and I found upsampling to the max sample rate supported by the DAC gave the best sound. 

 

Rgds

Svein