2" QUAD & DOLBY A QUERY

[rabruner at aol.com]

Attached Message
	
                    
			
From
			
Steele, Richard (HBO) <Richard.Steele at hbo.com>
                    
                    
			
To
			
quadlist at quadvideotapegroup.com <quadlist at quadvideotapegroup.com>
                    
                
			
Subject
			
2" QUAD & DOLBY A QUERY
                
                
			
Date
			
Fri, 26 Jun 2015 18:14:39 +0000
		
	


  
   
Hello Quad group,    
   
I have one question: at any time, was Dolby A noise reduction used on 2” Quad broadcast masters?  My guess, is the implementation of Dolby noise reduction only followed the decline or demise of 2” Quad as a broadcast medium.    
   
         
   
Any thoughts?    
   
         
   
Thanks.    
   
         
   
         
   
-richard steele-     
   
manager     
   
hbo archives     
   
2500 broadway, suite 400     
   
santa monica, ca 90404     
   
           
   
310.382.3234     

 WTTW in Chicago Produced a number of music shows in stereo before it was possible to broadcast stereo on television.  The shows were recorded on 24-track Ampex MM-1100s and mixed to stereo on specially modified Ampex VR-2000s and VR-1200s.  The video machines used split-track heads made for WTTW by ReDb and the electronics were modified versions of the Innovonics amplifiers similar to those used to retrofit Ampex 350s and 300s.  The edit controller was an Ampex RA-4000, later changed over to the CMX system.  All the audio to 2-inch was encoded with Dolby A.  WTTW owns WFMT-FM and they would simulcast locally produced stereo shows such as Sound Stage on WFMT to broacast the stereo audio, while feedding a mono mix to TV air. 
     During this period, WTTW was involved in a Joint venture with Telesonics to develop a method of broadcasting stereo over television and the facilities of the station were used in the overnight period to test the system.  It was in this develpment work that the principles of synchronizing to the stereo pilot with the video was developed as well as an appreciation of the importance of ICPM, Incidental Carrier Phase Modulation.  For many years, stereo TV receivers had a notice on the back of them that the set was manufactured under license from Telesonics.  WTTW was the first station in the country to broadast stereo using the newly developed system, in spite of what has been written elsewhere.  
     Later, all stereo production on video was done using Ampex VPR-2Bs using Dolby cards in place of the Ampex audio cards.  From that point on, all analog audio operations in the station, including network delay and relay were done with Dolby equipped 1-inch until newer technologies replaced reel to reel tape in all formats with cassette based tape, Beta-SP, D2, and DCT.  At one time, a series of a shows similar to Sound Stage, Center Stage, was done using Dolby SR on the 24-tracks, with the release product to the network on DCT.
    More recent Sound Stage shows were produced in High Definition, recording to digital servers and mixed on Pro Tools.  The console used initially for these shows was a 60-input Neve V, later replaced with a 128-input Oxford.  Video was recorded on HD Beta.
Bob Bruner
Engineer In Charge,
Maintenance and Design
WTTW/Chicago (Retired)

  

 
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