A Phoenix connector (also known as a Euroblock, Euro connector, or pluggable terminal block) is a type of two-piece disconnectable terminal block commonly used in professional audio and video equipment. The connector consists of a removable plug with screw terminals for securing bare wire ends, which then plugs into a fixed header socket mounted on the equipment's circuit board or rear panel. The name "Phoenix connector" comes from one of the original manufacturers, Phoenix Contact, a German company, though compatible connectors are made by numerous manufacturers.[1]
Design
The Phoenix connector is a two-piece system:
- Fixed header — soldered to the equipment's PCB, with pins matching the plug positions
- Removable plug — contains screw terminals (or spring clamps in some variants) that accept bare wire or tinned wire ends
The plug inserts into the header with a friction fit. Once wired, the entire plug assembly can be quickly disconnected from or reconnected to the equipment without disturbing the wire terminations — a significant advantage over permanent screw-down terminal strips where each wire must be individually unscrewed and re-attached.[1]
The screw terminals use a flathead or Phillips screwdriver to clamp wire. No soldering or specialized crimping tools are required for field wiring, making the connector practical for installation and maintenance of professional AV systems.
Common Configurations
Phoenix connectors are available in various position counts. The most common configurations found on AV equipment are:
| Positions | Typical Use |
|---|---|
| 2-position | Unbalanced mono audio (signal + ground) |
| 3-position | Balanced mono audio (hot + cold + ground) |
| 4-position | Stereo unbalanced audio |
| 5-position | Balanced audio + control signal |
| 6-position | Balanced stereo audio (hot + cold + ground × 2) |
The most common pin pitches in AV applications are 3.5 mm and 3.81 mm (0.15"), though 5.0 mm and 5.08 mm (0.2") pitches are also encountered.
Specifications
| Parameter | Typical Value |
|---|---|
| Pin pitch | 3.5 mm, 3.81 mm, 5.0 mm, or 5.08 mm |
| Wire gauge | 12–24 AWG (depending on pitch and terminal size) |
| Voltage rating | 150–300V (rated, but used at signal-level voltages in audio) |
| Connection type | Screw terminal or spring clamp |
| Coupling mechanism | Friction fit (pluggable) |
Use on AV Equipment
Phoenix connectors are widely used in professional and semi-professional audio and video equipment, including:
- Professional amplifiers — Crown, QSC, and other pro amplifier brands commonly use 3-pin or 6-pin Phoenix connectors for balanced audio inputs
- Video processors — some professional video scalers and processors use Phoenix connectors for audio pass-through
- Broadcast monitors — certain professional CRT monitors, particularly those designed for broadcast or surveillance applications, use Phoenix connectors for balanced audio or control signal inputs
- AV distribution systems — matrix switchers, distribution amplifiers, and control systems frequently use Phoenix connectors for both audio and RS-232/RS-485 control signals
- Intercom and tally systems — broadcast tally lights and intercom panels often use Phoenix connectors
The connector's ability to carry balanced audio signals makes it well suited for professional environments where long cable runs and electromagnetic interference are concerns. Balanced audio, using a hot, cold, and ground configuration on a 3-position connector, provides common-mode noise rejection that is superior to unbalanced RCA connections.
Wiring Conventions
For balanced audio on a 3-position Phoenix connector, the standard wiring convention is:
| Position | Signal | Notes |
|---|---|---|
| 1 (left) | Ground / Shield | — |
| 2 (center) | Hot (+) | Non-inverting signal |
| 3 (right) | Cold (−) | Inverting signal |
When connecting unbalanced sources (such as RCA) to balanced Phoenix inputs, a 2-conductor shielded cable is recommended, with the signal wire to pin 2 (hot), the return wire to pin 3 (cold), and the shield to pin 1 (ground).
See Also
- BNC — professional video connector
- RCA (connector) — consumer audio/video connector
- 3.5mm TRS — consumer audio connector
- Binding post — alternative speaker/audio connector
References
- ↑ 1.0 1.1 "Euroblock", Wikipedia.
