Orban Model 245E Stereo Synthesiser
A mono signal goes in, a wide, phase-safe stereo image comes out, and the sum of the two outputs still folds back to the original mono.
Overview
The 245E does one job. It takes a mono source and makes pseudo-stereo from it, and the two output channels sum back to the exact mono you fed in. That last part is the whole trick. Plenty of boxes will widen a mono signal. The 245E's patented approach is engineered so the stereo output is fully mono-compatible - add the outputs together and you get the original mono input back, intact.
The mechanism, as described in Orban/Parasound's own literature, is a five-band split. The mono source is divided into five frequency bands. Three of those bands go to one output channel and the remaining two go to the other. The filters are synthesized so that the sum of the two outputs is identical to the mono input. The effect is built on frequency division rather than delay or phase trickery, so the company claimed it causes no change in spectral balance, doesn't blur transient definition, and adds no audible noise or distortion to the mono original. The controls are deliberately minimal. The unit is meant to be dialed in for a given piece of program material in seconds, not tweaked endlessly.
This box was made for broadcast and studio work. The pitch from Orban/Parasound was aimed at the smaller FM station that wanted to process old records, announce mics, and mono spots without creating phase-cancellation grief for listeners in mono reception. For the recording studio, the angle was track economy: record strings, drums, or horns in mono, then spread them across the mix. It would also stereoize a mono reverb device and was pitched as ideal for reissuing old mono masters in synthesized stereo.
An early Orban/Parasound advertisement introduced the synthesizer at $299. The ad credited a redesign around state-of-the-art components, larger production quantity, and a stated 60% cut from the old price - "cut the fat from the package," as the ad put it. That is manufacturer marketing, not an independent verdict, but it's the clearest figure the documentation preserves. It makes the 245E an affordable utility rather than a flagship processor.
The trade press of the period treated it as a fixture of the Orban/Parasound line. Through the mid-to-late 1970s the 245E appeared repeatedly alongside the company's de-esser and parametric EQ in the "Price/Performance Leaders" and "Four of the Best" advertisements carried in Studio Sound (March 1977, p.27; November 1976, p.21; January 1979, p.25). There it was consistently described as using a unique, patented process to create realistic, mono-compatible synthesized stereo from a mono source. It also appeared in Studio Sound (September 1978, p.27) among the "Four of the Best" Orban advertisements, alongside the 516EC dynamic sibilance controller and the 622B parametric equaliser.
This is a problem-solver with a specific, well-defined job: mono-to-stereo synthesis that never betrays the mono fold-down. Buyers should expect a period broadcast/studio utility piece rather than a hi-fi toy, and should check cosmetic and functional condition carefully, since the available sources don't spell out detailed service documentation for the 245E. The design is five bands, a three-and-two split, exact mono reconstruction, and controls simple enough to set by ear in a few seconds.
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