Originally Posted by
lovejoy
Hi Richard,
Use the arrow keys on your Mac to navigate the various mixer options. The currently selected one will turn from white to red text in the options at the bottom of the screen.
PCM is your master volume - 86 is the 0dB level, anything into the red is boost. I have mine set to 96 which matches the output of my CD player. If you set this much higher you'll likely start to hear distorion. Most people seem to settle around 92-97 I think, but it's handy if you have another source (apart from vinyl) to compare it with.
Move to the right with the arrow key and you'll select 'DSP Prog'. This allows you to select one of the different filter profiles built into the DAC chip. Use up and down arrow to change the value as you would with the volume levels. I've settled on Low latency IIR with de-emphasis. There are changes in presentation for all profiles. You may find another one works better for you, so it's worth having a listen to them all. This one is definitely worth playing with.
The next one along - Playback - gives you a -6dB attenuation if set to 0 and no attenuation if set to 100 (these are the only two values). I can't really see a reason for setting this to -6dB if you have your PCM level set correctly.
The next one along is Playback Boost, which gives a further 0.8dB of gain. This one is subtle and again is an on/off switch. Mine is on, but I don't think it makes much difference.
The rest of the options are mostly concerned with muting periods and how things are handled if there is a problem. Leave these set as they are.
Once you exit (Escape key), it's best to do a soft reboot of the Pi, either from the Web interface or just type:
sudo reboot
from the terminal. This ensures your settings have been saved. If you remove power rather than do a soft reboot, the previous settings will return after the next reboot.
I was thinking a sticky would be a good idea....