[sdiy] CA3086 and CA3046?

[René Schmitz]

At 17:35 15.08.01 -0400, Dr Strangelove wrote:
>Well, the 3086 is used in the Oberheim SEM.  Their advertisements from the 
>time claim that tuning stability was better than ALL the competition.  Maybe 
>people are not using the 3086 because they're just *too* good. (:-)

Well, I think that is actually due to the circuit topology. Apart from
using a tempco resistor for temperature compensation, its reference current
is chosen so that the temperature dependancy is minimal. (Arround the
reference current the impact of drift is lower than at very low or high
frequencies.) Also the SEM has a Rbe correction, which renders the not too
great transistors in an 3086 or 3046 in a respectably precise expo convertor.

Cheers,
 René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159