The Texar Audio Prism, later manufactured by Gentner, was perhaps one of the best-sounding fully-analog multi-band broadcast processors.
In the history of audio processing, the TEXAR Audio Prism holds its own place as one of the key tools in the arsenals of stations fighting to produce their “signature” sound and stand out in their market. We asked Glen Clark to recall the days when he designed and built the Audio Prism, and how it became a “broadcast standard.” Broadcaster's Desktop Resource, June 2011. http://www.thebdr.net/articles/audio/pr ... oPrism.pdf
Texar Audio Prisim Stereo Pair on the Workbench
I wanted a stereo pair to experiment using them for home playback and possibly mastering to emulate an 80s broadcast sound.
The Audio Prisms are a four band level processor to be used ahead of an Orban 8100 processor and composite stereo generator.
The Orban 8100 had a narrow level sweet spot - the Texar kept things where they needed to be.
Once I started developing a large digital library I knew I needed a pair of these to keep listening levels in the sweet spot.
Properly setup, pretty much everything that goes in the Texar comes out better.
Texar Audio Prism Block Diagram
The "safety buffer" is a broadband gain control ahead of the four band split filters.
Texar Audio Prism M-101 Block Diagram
The four digital commands are "Quiescent," "Signal," "Expand" and "Peak."
The terms used are slightly different than what we normally think of.
Schematics have been notoriously hard to come by.
The units have been out-of-production for years and Gentner, who later manufactured the Audio Prism, is no longer in business.
I now have schematics and I see no harm in providing people the tools they need to repair their own Texars.
For now I'll start posting the schematics in bits and pieces but may later publish a circuit analysis once I figure it out myself.
The most unique thing about the Texar was its M-101 "Digitally-Controlled Audio Processor."
There are four of these gizmos in each Audio Prism.
The only primary path audio on these boards is through the Vactrol and it's source resistor.
The entire board is sidechain and display.
Texar Audio Prism M-101 Schematic
Texar Audio Prism M-101 Schematic
Schematic of Texar Audio Prism M-101 Digitally Controlled Audio Processor: https://proaudiodesignforum.com/images/ ... ematic.pdf
Texar M-101" Digitally-Controlled" Audio Processor Module PC Board.
There are four identical M-101 boards per channel.
The filters and timing capacitors are on the motherboard so the boards can be freely-swapped between bands.
The only primary audio path components on this board are a 15K (varies) resistor and the Vactrol VTL-5C3.
The rest of the "stuff" is the Digitally Controlled sidechain.
Documents added 10/21/2015:
Texar Audio Prism II Manual With Schematics 1991 https://www.proaudiodesignforum.com/ima ... s_1991.pdf
Texar Audio Prism M-101 Board Alignment https://www.proaudiodesignforum.com/ima ... gnment.pdf
Texar Audio Prism M-101 MB-2 Schematics https://www.proaudiodesignforum.com/ima ... matics.pdf (Source Broadcasters' Desktop Resource http://www.thebdr.net)
Gentner Audio Prism II Phoenix AM No Schematics https://www.proaudiodesignforum.com/ima ... nix_AM.pdf (Source: CircuitWerks http://www.broadcastboxes.com)
SEC Technologie Texar Audio Prisma III NRJ 2001Alternative Alignment https://www.proaudiodesignforum.com/ima ... J_2001.pdf (Source: Monisound! http://www.hollandfm.nl)
Texar Audio Prism Manual No M-101 Schematics 1988 https://www.proaudiodesignforum.com/ima ... s_1988.pdf
Texar Eagle AMC-1 Modulation Controller Schematic: https://www.proaudiodesignforum.com/ima ... roller.pdf
I'll drop back in later and provide credits to the above references. Thanks to everyone who has sent me material and all the websites hosting them.
More to follow...