[QuadList] Seeking DBX-700 digital audio processor--Ping Boston area folks

[Ted Langdell]

On Sep 29, 2012, at 4:07 PM, C. Park Seward wrote:

> Ted,
> 
>  I think you need that exact model to decode.


Exactly.  

That's why I'm looking for one. It is an A/D-D/A system that puts the encoded digital data into an analog composite video signal that can be recorded onto videotape. Commonly recorded on VHS, Betamax and 3/4.


On Sep 29, 2012, at 4:07 PM, C. Park Seward wrote:
> " Unlike other similar pieces of equipment like the Sony PCM-F1, the Model 700 used a technique called Companded Predictive Delta Modulation, rather than the now-common pulse-code modulation."
> 

Here's how the modulation scheme worked:
http://en.wikipedia.org/wiki/Delta-sigma_modulation

And here's the Wikipedia item on this particular tool:
http://en.wikipedia.org/wiki/Dbx_Model_700_Digital_Audio_Processor

The Model 700 had been designed from the beginning to have many 'tape-like' characteristics, including "soft saturation," and at a time when most professional and amateur recordists were used to analog tape, this was considered a significant feature. It also offered 14dB more dynamic range than 44.1kHz/16b audio, and because of its very high sample rate (644kHz), it did not contain the same anti-aliasing filters necessary in PCM recorders at the time, which were thought to cause undesirable harmonic interference.

The Wikipedia entry notes that WGBH-FM used one as its STL.  (Which provides a lead!)  

Perhaps Tom or Paul in Boston has an idea whether there are any floating around.

Ted 

> On Sep 27, 2012, at 9:51 AM, Ted Langdell wrote:
> 
>> 
>> Looking for a DBX-700 digital audio processor or something that can decode this digital audio in video format.
>> 
>> Rent or buy.
>> 
>> Thanks.
>> 
>> Ted Langdell
>> Secretary
>> Skype: 	TedLangdell
>> e-mail:	ted at quadvideotapegroup.com
>> 
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Ted Langdell
Secretary
Skype: 	TedLangdell
e-mail:	ted at quadvideotapegroup.com

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