Hi-fi Standards – Signals and Connectors

There are three different "levels" of analogue connections you might come across in "normal" hi-fi… 

"Line level" is typically a signal between -2 and +2 volts. This signal is typically put out by:


  • CD / DVD players on phono plugs
  • VCRs on either phono plugs OR certain pins on the SCART socket
  • The "tape out" sockets on an amplifier
  • The "pre-out" sockets on a pre-amplifier

… you plug it into an amplifier (either integrated-, power- or active speaker-)

"Phono" level is a much lower level put out by the cartridges of record decks. You either need a "phono stage", which is a separate box that takes phono level inputs, and has line level outputs, which then feed toyour amp OR you have an amp which has a built-in phono stage (and oneset of input sockets marked up a "phono", which you should NEVER use for a line-level source.)

This gets confusing when you're talking since the word "phono" is used with two differnt meanings. Firstly, these lower-level input voltages. Secondly, the 3.5mm round sockets that both "phono" (first meaning) AND line level signals can travel on.

"Speaker level" is typically between -50 to 50 volts. This typically comes out of either an integrated or a power amp, and goes to a PASSIVE or ELECTROSTATIC speaker. If your speaker is just a "box with input terminals" on it, it's passive. If your speaker has a mains lead running into it, it's either ACTIVE or ELECTROSTATIC. If it's Electrostatic, it wants a "speaker level" input.


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