The Sony RGB MULTI INPUT is a 34-pin IDC-style connector, mechanically identical to a standard floppy-drive header, used on Sony Trinitron XBR and Profeel series monitors and televisions from the mid-1980s. It appears on models including the KV-25XBR, KV-20XBR, KV-1311CR, KX-1901A, KX-2501A, and KX-27PS1. The connector carries analogue RGB video (Red, Green, Blue inputs with individual ground returns), horizontal and vertical sync (or composite sync), a blanking input, stereo audio inputs, a +5 V power supply, and two mode-select lines that switch the display between RGB and normal (composite) video modes. The associated cable is Sony part number PX-34. Each signal line and its corresponding ground return should be wired as a twisted pair: pins (8, 25) for Red, (9, 26) for Green, (10, 27) for Blue, (12, 29) for Blanking, (13, 30) for H. sync, and (15, 31) for V. sync. Audio input level is 408 mVrms at 100 % modulation into 47 kilohms.
| Pin | Description |
|---|---|
| 1 | +5V power supply |
| 2 | +5V power supply |
| 3 | Audio (R) input GND |
| 4 | GND |
| 5 | Remote control GND |
| 6 | Composite video output GND |
| 7 | Audio (L) input GND |
| 8 | Red Return (GND) |
| 9 | Green Return (GND) |
| 10 | Blue Return (GND) |
| 11 | GND |
| 12 | Blanking input Return (GND) |
| 13 | H.sync Return (GND) |
| 14 | N.C. |
| 15 | V.sync Return (GND) |
| 16 | GND |
| 17 | N.C. |
| 18 | N.C. |
| 19 | N.C. |
| 20 | Audio (R) Input |
| 21 | Mode Select |
| 22 | N.C. |
| 23 | Composite Video Output |
| 24 | Audio (L) Input |
| 25 | Red Input |
| 26 | Green Input |
| 27 | Blue input |
| 28 | N.C. |
| 29 | Blanking Input |
| 30 | H.sync or composite sync |
| 31 | V.sync |
| 32 | N.C. |
| 33 | RGB/NORMAL mode select |
| 34 | Audio Select |
Notes
The 34-pin IDC plug is mechanically interchangeable with a standard 34-way floppy-drive ribbon-cable connector. Pins 14, 17, 18, 19, 22, 28, and 32 are not connected (N.C.) in the KV-25XBR implementation. Each video signal line must be routed with its dedicated ground-return pin as a twisted pair to minimise interference: (8, 25) Red, (9, 26) Green, (10, 27) Blue, (12, 29) Blanking, (13, 30) H. sync/composite sync, (15, 31) V. sync. The Sony PX-34 cable assembly incorporates this twisted-pair wiring. Not all Sony monitors that carry the RGB MULTI INPUT socket implement every pin identically; consult the service manual for the specific model before wiring a custom cable.
Signals
- +5 V power supply (pins 1–2) — 5 V DC supply provided by the monitor to power external RGB source equipment.
- Audio (R) Input (pin 20) — right-channel analogue audio input; nominal level 408 mVrms (100 % modulation), input impedance 47 kilohms.
- Audio (L) Input (pin 24) — left-channel analogue audio input; same level and impedance as pin 20.
- Audio Select (pin 34) — selects the active audio source when the monitor is in RGB mode.
- Mode Select (pin 21) — switches the monitor between RGB input mode and normal composite video mode.
- RGB/NORMAL mode select (pin 33) — secondary mode-select line; works in conjunction with pin 21 to control input routing.
- Red Input (pin 25) / Red Return GND (pin 8) — analogue red channel signal and its dedicated ground return; wire as a twisted pair.
- Green Input (pin 26) / Green Return GND (pin 9) — analogue green channel signal and its dedicated ground return; wire as a twisted pair.
- Blue input (pin 27) / Blue Return GND (pin 10) — analogue blue channel signal and its dedicated ground return; wire as a twisted pair.
- Blanking Input (pin 29) / Blanking input Return GND (pin 12) — external blanking signal that suppresses the raster during RGB display; wire as a twisted pair.
- H.sync or composite sync (pin 30) / H.sync Return GND (pin 13) — horizontal sync or composite sync input; wire as a twisted pair.
- V.sync (pin 31) / V.sync Return GND (pin 15) — vertical sync input; wire as a twisted pair.
- Composite Video Output (pin 23) / Composite video output GND (pin 6) — composite video output from the monitor (pass-through or tuner output).
- Remote control GND (pin 5) — ground reference for the remote control signal path.
- N.C. (pins 14, 17, 18, 19, 22, 28, 32) — not connected in the KV-25XBR implementation.