|Do I have to get the 6081 special DC
decoder if I have e.g. Fleischmann, Lima or Roco DC locos that I wish to run
with Märklin Digital ?
No, you can actually use the Delta decoder too if you make a little add-on circuit to it. Then you have the benefit of getting a cheaper decoder and still be able use the original DC motor in "non-Märklin" locos.
You will of course need to have some very basic soldering skills, but you will only need 6 cheap components.
The electrical principle is to add a "H-bridge" to the Delta decoder board output to make it produce "pure DC" to the motor... This principle can be applied to the 6080 "AC" decoder too.
The components needed are 2 pieces of 2,2
k-ohm resistors, 2 pieces of 4,7 k-ohm resistors and 2 PNP Darlington
transistors as egg the BD680. If you can't find the BD680, or need to have
smaller SMD equivalents, the data sheet of the BD680 can be found here for comparison, you can download the specs as a PDF ( Acrobat Reader
) file... There are SMD equivalents too, but I don't know the codes