Intellivision 2 Composite Mod

Steve,

I added composite video and audio outputs to my Intellivision II using OGHUGO’s Retro Mod Shop INTV Composite kit. Stock, the Intellivision II only outputs RF, which looks soft and noisy on a modern TV.

Composite gives a cleaner picture and plugs into most TVs and upscalers. If you can solder, this mod isn’t hard.

The Kit and Parts

The kit is OGHUGO’s INTV Composite board, version 1.3. It’s a small amplifier board with a 2N3904 transistor, several 100 µF capacitors, and a 75 Ω resistor on the video output.

The board has seven labeled pads:

SidePadsPurpose
InputsGND, A IN, 12V, V INGround, raw audio, power, and raw video from the console
OutputsGND OUT, V OUT, A OUTGround and the buffered video and audio for the jacks

For the outputs I used three gold-plated panel-mount RCA jacks: yellow for video, plus white and red.

OGHUGO INTV Composite V1.3 board
Gold-plated yellow, white, and red RCA panel-mount jacks

What you’ll need: the kit, RCA jacks, hookup wire, a soldering iron and the 3D printed RCA jack housing.

Opening It Up

With the shell off, you can see the main board with the General Instrument chipset, including the CP1610 CPU, the AY-3-8915 color chip, and the AY-3-8914A sound chip. The RF modulator sits in a silver Astec can in the top corner, and the power supply is a separate brown daughterboard screwed down beside it.

That power board is an Astec AA7170 (Mattel part 5872-9539, made in Hong Kong). Mine was covered in dust and still had its original capacitors, so I recapped it while I was in there.

Old caps dry out and can cause hum, instability, or a console that won’t power on. If you recap yours, take a photo first and note each cap’s value, voltage, and polarity.

Astec AA7170 power board removed from the Intellivision II
Astec power board installed next to the RF modulator
Close-up of the capacitors on the Astec power board
Side view of the Astec power board

Installing the Board

I mounted the composite board on top of the RF modulator can to keep the wires short.

  1. Mount the board on top of the RF modulator shield with double sided tape.
  2. Wire GND to a ground point on the modulator or main board.
  3. Wire 12V to the console’s 12 V supply feeding the modulator.
  4. Wire V IN to the video signal going into the modulator.
  5. Wire A IN to the audio signal going into the modulator.
  6. Double-check every joint for bridges before powering on.

I used red for 12 V, black for ground, and white for the signal lines.

Wiring the RCA Jacks

The outputs run from the board’s V OUT, A OUT, and GND OUT pads to the RCA jacks. Video goes to the yellow jack’s center pin, and every jack’s ground lug ties back to GND OUT.

The Intellivision’s audio is mono, so the board has a single A OUT. [Did you bridge the white and red jacks so both carry audio, or leave one unconnected?]

I used a 3D printed housing for the RCA jacks.

Rear of the Intellivision II with the new red, white, and yellow RCA jacks next to the original RF output

Testing and Results

Before closing the shell, I powered it up with a cartridge in and the case still open. The power LED came on and the picture quality was immediately noticeably better!

Final Thoughts

OGHUGO’s board is well labeled and the install doesn’t take long. The picture is a lot better than RF.

This was an easy mod that I definitely recommend!

Repair and Modding