using volumio as both an airplay device and a direct play device through the web. i have it connected to a pair of computer speakers using the 3.5mm, no additional equipment.
it seems that no matter what volume i physically set the speakers to, i can’t seem to get any audio between 0-50, and all of the sound is compressed between volumes of 50-100 (estimated). are there any fixes for this?
You could use a phono preamp to increase the signal levels but that is also increasing a bad signal to become worse.
Easiest (and probably evenly expensive as buying a phono preamp), best way is to hookup a small device on the I2S interface of the Pi that is able to generate a good signal. This could be an analog signal using a I2S DAC or a digital signal using something like a Hifiberry Digi(+). Both type signals need to go into a proper amplifier to drive your speakers.