The Audio Designer F769X-R Vocal Stresser is a classic and was manufactured in the UK in the 1970's it comprises 2 separate sections, E900 4 band Equaliser and the F760X Compex Limiter.
I remember seeing Audio & Design advertisements in Studio Sound in the 19970's featuring Tony Visconti with a picture of him walking in the West End with a Vocal Stresser under his arm. The Vocal Stresser was the forerunner to the wide range of Voice channels available these days.
The E900 is a 4 band sweep EQ with a 3 position switches on each band, Dip - O (flat) - Peak, the E900 can be placed before or after the Compex Limiter or into the side chain of the Compressor.
The F760X Compex Limiter is a Peak Limiter, Compressor, Expander combination. Audio & Design Compressor / Limiters were found in early Helios & Trident mixers.
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