Expert Settings is a way for us to quickly introduce new tuning parameters that:

• may influence sound quality
• require some underlying knowledge of the parameter, its influence on sound quality and on the system as a whole
  
• depend a lot (in usage and in results) on nuances of a particular system
• are not adequately tested (in the least they will simply not work but they can also make your system unstable)
• are of the "on your own risk" nature - if you mess up your system we will sometimes try to help restore it quickly but in general we will just instruct you to reinstall everything (that is something you can always do)

While our Expert Settings Disclaimer statement may sound scary (which was on purpose - we do not want to encourage people to just blindly experiment with things they do not understand), not all Expert Settings are equally dangerous. With some of them you can only mess up your sound quality, with others you can make the system slow or even unresponsive while with some you can actually damage your equipment.

That is why we will issue several articles about specific Expert Settings that are safer to use and explain:

• how to use them
• what is the underlying theory 
• exactly how dangerous (or not) they are

We also noticed that some users are confused with placeholder text which is meant to shortly provide the purpose or example of a particular field usage but which (when all fields are empty) may look like actual text entered into fields (the text has gray-ish color but with absence of filled out fields this is not entirely obvious).

We will cover in separate articles:

• Min/max CPU freq
• CPU isolation
• ethtool command line params
• Interface / time (playback with disconnected network)

and briefly explain others in this article.

Buffering RAM (GB)

Euphony has a couple of features that use RAM to hold song files before playback - in order not to engage a disk or network at playback time.
By default the amount of RAM reserved for that is half of your total RAM available. If you have a lot of RAM you may want to increase that amount so you can buffer more songs at once. Even when you want to maximize that amount spare a few GB for the system itself.

In the field you enter only a number for desired amount of GB.

As long as you do not try to reserve all RAM for this and you don't mistakenly enter more than you have, this feature is fairly safe to use.

Use only with Stylus! Roon and other audio systems (even StylusEP) will not benefit from this. 

WIFI

You cannot mess anything up by trying to connect to your WiFi network by entering SSID and WPA password. This feature is in Expert Settings mostly because it is very hard to have all WiFi network drivers included in Euphony image.
If you can connect - great! Afterwards, you can even disconnect Ethernet and use WiFi from there. Otherwise, if you cannot connect because of a missing driver you are out of luck - we will not be including any additional WiFi drivers to our image. If WiFi usage is mandatory for you instead of your current WiFi chip, try obtaining some USB WiFi adapter and see if it works.

Disk spin-down timeout

If your OS disk is an actual rotating disk drive and not SSD drive you may want to reduce the interference of disk spinning all the time by entering some period after which the disk will stop spinning if inactive for that amount of time.
You enter just a number: amount of seconds after which disk will stop spinning if inactive for that entire time.
This option makes sense when you only play from network storage (and don't select 'Use cache' option) and if you set Euphony logging to 'none' in Settings - System - System info.
Be cautious with this as spinning the disk up very often can reduce disk longevity.   

Squeezelite command line params

Squeezelite was initially meant as an alternative to RoonBridge for Roon playback but since we introduced StylusEP and most people agreed that it sounds better than RoonBridge and better than Squeezelite even with highly tuned parameters not many people even ask what should go here. Your best bet is to search AudiophyleStyle forum for specific examples if you must convince yourself about relative SQ of these options.

Stress CPU

If you want to measure the maximum power that Euphony machine may require or just test how well your passive thermal isolation works or if you want to break-in your power supply and power cables - you can force Euphony machine to be at 100% CPU utilization. Depending on the chosen setting only some or all cores will be at 100%.
This can be very dangerous - if you leave this stress test running on an unattended machine - not monitoring your CPU temperatures either through software or just by touch you can easily damage your equipment or even cause fire!