A quick introduction to my setup :
Raspberry Pi 2 running latest Volumio 2.0
Hifi Berry DAC
Amplifier is homebuilt from a kit supplied by 41hz several years ago. Class D amp of 40W output. Superb sound quality with exceptionally low distortion figures. Runs from an internal power supply and toroidal transformer.
Homebuilt passive preamp running a quality Panasonic Rotary.
Speakers are homebuilt in 1990s, not by me. Wilmslow Audio kit speakers purchased from EBay. Exceptional sound quality.
NAS device for music storage but mostly use Spotify.
All this has cost me very little and is exceptional sound quality. The sound always surprises me.