Upgraded my home Audio system this year.. Nothing crazy or high-end, but sounds incredibly nice...
This is the starting point. Bluesound Node N132 music streamer. This thing has a 1.8GHz quad core processor. Got a premium DAC (Digital-to-Analog Converter) built in. Supports HDMI eARC too, so my TV is also connected via HDMI for home theatre sound.
Analog signal then goes to a Fosi Audio GR70 Tube Headphone Amp/Preamp. This thing adds warmth to the sound (amplification is purely analog).
Output from tube amp goes to a two channel Class-D amp. This is a HYPEX NC252 module. Not insanely powerful (2x 250W @ 4Ω), but fantastic sound resolution and creates pretty much zero distortion or noice.
Then the final piece where sound comes out. Bowers & Wilkins 606 S3 bookshelf speakers on genuine B&W stands. These don`t produce house-shaking volume, but sound quality is extremely good for the size. My theatre room is about 4m x 5m, produces more than enough volume for this room size.