Quick answer: A phono or RCA plug carries either composite video at 1 V peak to peak into 75 ohm or line audio at about 2 V root mean square, and only a powered converter turns either into HDMI. Budget AU$25 to AU$70. Composite and component reach 1080i at best, audio arrives as stereo PCM, and the analogue path is free of HDCP, which is why it still suits capture work. S-Video on a 4 pin plug is the better analogue option where the source offers it.
Six identical looking plugs on the back of a set top box carry three different signals, and the colour of the moulding is the only guide. Feed a 1 V video signal into an audio input and you get hum; feed 2 V audio into a video input and you get a rolling picture. Get the levels right and the conversion to HDMI is routine.
Three RCA Plugs, Three Different Jobs
Yellow, red and white
Yellow is composite video: brightness, colour and sync on one conductor, 1 V peak to peak, 75 ohm impedance, and about 5 MHz of usable bandwidth. White and red are left and right line audio at 2 V root mean square into 47 kohm, with a flat response to 20 kHz. The three shells are identical.
Green, blue and red for component
Component video uses three plugs marked Y, Pb and Pr, with luma at 1 V including sync and the two colour differences at 0.7 V. Component carries 576i, 576p, 720p and 1080i cleanly. Colour shells vary between brands, so read the moulded letters.
Signal Levels That Decide Whether It Works
A converter expects the standard levels and terminates in 75 ohm. Undersized video from a long thin lead shows as a dark, noisy picture, and a missing 75 ohm terminator causes ghosting and double edges. Keep analogue runs under 3 m where possible, and use RG59 or RG6 patch leads rather than the thin cables packed with a DVD player.
Audio needs less care but more attention to level. Consumer line output at 2 V root mean square overloads a microphone input and disappears into a professional +4 dBu input, so converters with a gain trim are worth the extra AU$15.
The HDCP Free Path and Capture Cards
HDMI links carry HDCP, and a source that demands it will refuse a capture device that does not hold a licence. The analogue output on the same device carries no such flag, so composite or component into a converter, then HDMI into a capture card, records without a handshake argument. That is a legitimate path for your own footage, not for copying rented content.
Choose the capture end with care. An hdmi to usb adapter that accepts 1080p60 over USB 3.0 gives a clean recording without a PCIe card, and the converted signal at 1080p60 needs 4.95 Gbit/s, well inside USB 3.0 headroom. Confirm the adapter lists 1080p60 rather than 1080p30.
| Plug | Signal | Level | Typical source |
|---|
| Yellow | Composite video | 1 V p-p, 75 ohm | DVD player, set top box |
| White | Left audio | 2 V rms, 47 kohm | Television, console |
| Red | Right audio | 2 V rms, 47 kohm | Television, console |
| Green | Y luma | 1 V p-p with sync | DVD player, Wii |
| Blue | Pb colour difference | 0.7 V p-p | DVD player, Wii |
Fitting Plugs to Jacks Without Damage
Tight shells and bent pins
A phono plug is 3.2 mm across the centre pin and grips by friction on the outer ring. Cheap moulded plugs are often 0.2 mm oversize and stretch the jack, after which every cable fits loosely and hums. Push straight in, never twist, and replace a cable that needs force rather than working the socket loose from the circuit board.
Extending the converted run
Once the signal is HDMI, distance becomes the limit. A passive lead holds 1080p60 to about 5 m, and beyond that an hdmi cable extender over Cat6 carries the same picture to 40 m without loss. The hdmi cable rating categories guide sets out which tier suits 1080p, 4K30 and 4K120, and a Premium High Speed lead is enough for any converted analogue source.
Send the source model, plug colours and cable run to zongcarrie@zh-zong.com or call +86 13543026126 for a converter and cable list with AUD pricing and delivery to Melbourne, Sydney, Adelaide or Darwin.
Practical scenarios
- Situation: A Brunswick weatherboard house has a 1998 DVD player and a wall mounted 4K panel. What to do: Use component if the player has it, convert to 1080p60, and keep the lead under 2 m.
- Situation: A Cairns hotel AV rack needs four legacy sources on one display. What to do: Convert each source separately, then switch the HDMI outputs rather than the analogue ones.
- Situation: A Perth hobbyist records retro console footage on a laptop. What to do: Convert composite to HDMI at 1080p60 and capture through a USB 3.0 adapter.
- Situation: A Parramatta apartment has a turntable with red and white outputs and a soundbar. What to do: Use a phono preamp into line level, then an audio embedding converter rather than a video box.
FAQ
Is a yellow RCA plug the same as composite?
Yes. Yellow moulding is the informal standard for composite video on consumer gear, and the plug itself is an ordinary phono connector. The same shell appears in red, white, green, blue and black, so rely on the device labelling rather than colour alone, especially on imported equipment.
Can red and white audio go into green and blue jacks?
Physically the plug fits, but the signal is wrong. Component inputs expect 0.7 V video with sync information, not 2 V audio, so the display shows a rolling or blank image and the audio is not decoded anywhere. Use the audio inputs marked L and R, or a converter with audio embedding.
Do I need HDCP support to capture footage?
A capture device needs HDCP handling only when the source applies it. Analogue composite or component outputs carry no HDCP flag, so a converter feeding HDMI into a capture card records without negotiation. Keep the setup for material you own, since bypassing protection on rented or streamed content is not a lawful use.
