Phono Jacks: What the Sockets Really Mean
Phono jack is the socket side of the RCA world, and the word carries a trap: phono level is not line level.
Quick Answer
| Jack label | Expects | Note |
|---|---|---|
| Aux / Line | Line level RCA | Standard consumer level |
| Phono | Turntable phono level | Includes RIAA preamp stage |
| Sub out | Single mono LFE | One jack, not a pair |
| Rec out | Line level to recorders | Output, not input |
| Digital coax | S/PDIF data | Orange, not analogue |
The Phono Confusion
Two meanings
Phono jack describes the RCA form; a phono input is a turntable input with RIAA equalisation.
Plugging line into phono
Loud and distorted; the preamp amplifies an already hot signal.
Plugging phono into line
Quiet and thin; the RIAA shaping never happens.
Colour codes
Red right, white or black left, orange digital. Yellow is video on AV gear.
Working With RCA Sockets
- Match the label to the source: phono only for turntables.
- Keep the switch on turntables matched to the jack.
- Check sub out is mono before using Y cables.
- Clean oxidised jacks with contact cleaner.
- Replace jacks with cracked insulators.
Real-World Applications
- Vintage receiver setups.
- Modern amp turntable inputs.
- Recorder patching.
- Home theatre sub wiring.
Related Guides
For the plug side, read RCA plugs. For turntable detail, see turntable RCA cable. For cable runs, start with audio cable RCA.
FAQ
Are phono jacks the same as RCA?
The connector, yes. A phono input adds turntable equalisation.
Why is phono input distorted with other sources?
RIAA preamp boosts an already line level signal.
Can I use any jack for the sub?
Use the labelled sub or LFE output for correct bass routing.
Why is the digital jack orange?
Convention distinguishing S/PDIF coax from analogue pairs.