Hi-fi, explained

How a music system works

Music travels from the streaming service to your ears through a few parts. Each one does one job. Here they are, in order.

Follow the musicFind your device

Setups

One chain, many boxes

A phone does the whole chain in your pocket. Hi-fi gear splits it into boxes. Pick one to see which parts it does.

A phone playing music

A phone

Everything up to the headphones is inside the phone: the streaming app is the streamer, and a small DAC, a volume control and a headphone amplifier drive your headphones. That amplifier is too small for passive speakers, but the same output can feed active speakers.

Then: Headphones or active speakers

The chain

From the music to your ears

Six parts, one after the other. Under them, a power supply for each box, and the controls tell them what to play.

Controls The app or a remote tells the streamer what to play

  1. MusicWhere the music lives
  2. StreamerFinds the music and plays it
  3. DACTurns numbers into a sound wave
  4. PreampPicks the input and sets the volume
  5. AmplifierAdds power to move the speaker/headphone membrane
  6. Speakers/headphonesTurn the signal back into sound
  1. Power supply for the streamer
  2. Power supply for the DAC
  3. Power supply for the preamp
  4. Power supply for the amplifier

Power supply One for each box that needs power, under the chain

Fewer power supplies

One supply can feed two boxes.

  • Lineo5 DuoOne linear power supply with two independent outputs: it powers two boxes at once, such as the streamer and the DAC.

Start from what you have: see the devices that fit your chain

The parts

Each part, one job

What it does, where it sits, and what you may already own that does it.

01. The music

Where the music lives

Music starts out as files: on a streaming service such as TIDAL, Qobuz or Spotify, on a drive at home, or on a CD. Web radio is music too, streamed live.

Where it sits
At the start. It reaches you over the internet or your home network.
You may already have one
Your streaming apps, the files on your computer, a USB stick, your CDs.

02. The streamer

Finds the music and plays it

The streamer is the brain of the system. It fetches the music over your network, keeps your queue and does what you ask in the app. It passes the music on as digital data: still numbers, not yet sound. A streamer with no DAC inside is called a transport: it sends the music out to a separate DAC.

Where it sits
After the music, before the DAC.
You may already have one
A phone or a PC/Mac playing Spotify. A Raspberry Pi with Volumio OS.
Volumio RivoA streamer that sends a clean digital signal to your own DAC: a transport.

03. The DAC

Turns numbers into a sound wave

Digital music is a long list of numbers. The DAC (digital-to-analog converter) turns them back into an electrical wave, the analog signal. A better DAC draws that wave closer to the recording.

Where it sits
After the streamer, before the preamp and the amplifier.
You may already have one
Every phone and PC/Mac has a small one behind its headphone jack. A USB DAC, or a DAC board on a Raspberry Pi.
Volumio PrecisoTurns the digital signal from your transport into analog, with two SABRE DACs, one for each channel.

04. The preamp

Picks the input and sets the volume

The preamp (preamplifier) chooses what you listen to, such as the streamer, a turntable or the TV, and sets the volume. It is often built into the DAC or the amplifier, so it may not be a box of its own.

Where it sits
After the DAC, before the amplifier.
You may already have one
The volume buttons on your phone.
Volumio Primo PlusA streamer DAC with a preamp mode: three parts in one box.

05. The amplifier

Adds power to move the speaker/headphone membrane

The signal from a DAC is too weak to move a speaker. The amplifier makes it strong enough. An integrated amplifier has a preamp inside.

Where it sits
After the preamp, before the speakers.
You may already have one
The tiny amplifier in your phone drives your headphones. Powered speakers have one inside.

06. The speakers

Turn the signal back into sound

A speaker moves air: its drivers push and pull with the music, and you hear it. Passive speakers need an amplifier. Active, or powered, speakers have one inside. Headphones are small speakers for your ears.

Where it sits
At the end of the chain.
You may already have one
Your headphones, a Bluetooth speaker, the speakers of your TV.
Passive speakersThey need an amplifier. Speaker cable carries the amplified music to them. Most hi-fi bookshelf and floor-standing speakers are passive.
Active speakersThe amplifier is inside, so they plug into the wall and connect straight to a DAC. Studio monitors and many desktop speakers are active. Wireless speakers go further: the streamer and the DAC are inside too.

07. The power supply

Feeds every box clean power

Every box needs power. Noise on the power line can end up in the sound, so audio gear often uses quiet, steady power supplies.

Where it sits
Under the chain: one for the streamer, one for the DAC, one for the preamp, one for the amplifier. It powers the boxes, not the music itself. One supply can feed two boxes.
You may already have one
Your phone's charger. The USB-C power supply of a Raspberry Pi.
Volumio Lineo5A low-noise linear power supply for Volumio streamers and other 5 V audio gear.

Your turn

Pick the parts you need

The device guide asks what you have and suggests a Volumio device. Or build your own streamer with a Raspberry Pi.

Find your deviceDownload Volumio OS