dbx 216 noise reduction

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bruno2000

Well-known member
Joined
Dec 29, 2007
Messages
1,570
Location
Atlanta GA
Does anyone out there know what kind of dbx "cans" are in the dbx 216 (310A) noise reduction modules?  They are black, and the same size and shape as the 202s, but have no markings on them.
Thanks!
Merry Christmas!
Bruno2000
 
Basically, the RMS modules are more or less functionally identical. They all operate on the same principle of accelerated RMS detection (averaging the log). There's not a lot of difference to be expected operationally between the very oldest potted modules and the newest monolithics.
Almost the same could be said for the VCA's except there were three main functional variants:
6.02mV/dB, which is the natural control law for the core, and
5V/100dB or 10V/100dB, both obtained by a voltage divider in the control port
It is relatively easy to determine what type by measuring the control voltage under working conditions. The first type will measure at a few hundred mV max, when the others will show a few volts.
There's a whole lot of difference between potted VCA's: the original one operated in class B, then some in class AB. The THAT corp website traces the history of VCA's and their variants, but it is quite difficult to know which is what. It seems that a number of ECO's have not been very well documented, or lost through the numerous changes of ownership/location.
 
Thanks for the info!  I've got a bunch of these, and will be happy to send some out to folks who want to experiment with them.
Merry Christmas!
Bruno2000
 
There was a recent post http://www.groupdiy.com/index.php?topic=34707.0 where someone wanted to clone a dbx160VU. The main difficulty is getting the potted modules. This guy may want to get these modules from you.
 

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