Andreas,
beside amplified popcorn noise I again do have a temperature influence on the 6,95V --> 10V amplifier. This is why I will replace the 82k 25ppm/K resistor by a 82k2 5ppm/K one, that is in parallel to a 10k 2.5ppm/K in the amplifier. Hope to get the resistor by the middle of next week.
The original 5ppm/K smd resistors where fine, after they where preaged incircuit (with crystal heater on) and after crystal heater turned of. However, I wanted to see what difference I can achieve by through hole components, so I replaced them by AE 2.5ppm/K resistors (10k and 20k).
-branadic-