Quite right. But the DT2765 was a variation of the DT2762, which is what 
DEC re-labelled as the ADV11C.  The ADV11C was even faster that the 
AAV-11.  However, the flying capacitor isolation through a reed relay gave 
high-voltage rejection at the expense of speed for instrumentation 
applications. When I said it could measure millivolts against a common mode 
voltage in the hundreds, I mean that it could read something like a 
transducer with a high bias.  It doesn't measure the voltage common to both 
terminals, just the millivolt difference between them.  If you want, you 
can change the gain and measure higher voltages, but the speed is still low.

I would imagine that an adv11c driver would be pretty close to working 
except that the front-end gains would have to be fudged.

Sorry to get an off-topic going to such details.

regards

Nigel Johnson


At 16:53 02-10-25 -0400, you wrote:
>the AAV11 i have claims in the documentation to be able to handle
>multiple 30 KHz channels at once.. definitely good enough for nice audio.
>maybe it's a different board. the VAXlab stuff is three boards i think..