Extron Interface Trick for Downscaling

Extron Interface Trick AKA Extron 240p trick, pseudo 240p. Extron VSC unit + RGB Interface with DDSP

An Extron VSC 500 and Extron RGB 580xi were used in the Downscaling Chronicles, but the VSC 500 can be substituted for another model like the VSC 700.

Type: Blend/Bob-De-Interlace, very soft with mild flicker

Setup required: None

Cost and availability: High cost to benefit, relatively available second hand


The Extron Interface Trick is a 2-step process;

  1. An Extron VSC downscales 720p/480p to 480i RGB or YPbPr (input and output formats will be the same)
  2. The VCS’s output is fed into an Extron RGB interface with DDSP (Digital Data Sync Processing). By turning off DDSP, the 480i output will be drawn to the same field each frame. As each scanline were initially meant to interlace ie draw to alternating fields, the resulting image will appear to ‘bob’. Turning up the VCS’s flicker filter to maximum will somewhat stabilise the image, but not completely.

The slight flickering and heavy vertical filtering results in an incredibly soft downscale. Even compared to less sharp downscalers like the Corio2 tvOne and the Extron Super Emotia, the output from the Extron Interface Trick is offensively blurry:

Cool hack, right? Well there’s a catch… 240p output is unpredictable and completely dependant on the CRT’s processing of sync. The vast majority that have tried this method could only downscale to 480i, but NOT 240p. With a VSC 500 and RGB 580xi combo, I tested this method on 7 CRT’s where 240p output only worked on 1 display; a Sony BVM 20F1. If you already have the equipment then by all means see if your CRT is anointed, and putting aside the incredibly soft and slightly jittery image, this is not a viable option for the masses. As for the Extron VSC units, apart from horizontal screen tear, the fluid picture controls and ability to output all types of RGB sync, YPbPr, S-Video AND composite, makes them solid performers to downscale to 480i. Just skip the RGB interface for pseudo 240p on this one.

Verdict: Not Recommended

Further recourses: 

Video Game Perfection’s writeup

Fudoh’s Hazard City: Scanlines Demystified site