INSTRUCTION MANUAL

Decoder MX620 - MX622, MX630 - MX632 Sound Decoder MX640 - MX648 Page 47
Summary of actions when "The sound is too loud"
This subject corresponds to a frequent request of model railroaders, who find ZIMO sound decoders
as OEM equipment in locomotives (Roco, Fleischmann, Hag... since 2010), which often have the
volume set at the factory to the maximum value in order to increase the effect ...
The simplest corrective action to take is of course to lower the overall volume with the help of CV
#266, by reading the value first and subsequently programming a lower value. However, this will of
course influence not only the driving sound but also the function sounds (whistle, horn, brake squeal
etc.), with the result that the latter often become too quiet. Therefore…
Reduce driving sound volume (WITHOUT changing the function sounds) for STEAM engines:
Read out the values in CV’s #275, #276, #283 and #286 (see CV table for detailed information) and
program with lower values. It is often enough to simply modify the CV’s #275 and #276, which are
relevant to cruising speed and it is often only at that speed that too high a volume is annoying.
NOTE (also applies to DIESEL and ELECTRIC engines): The default values shown in the CV table
are most often not used because other values are used within the sound project. That’s why the actual
values should always be read out first, followed by programming a (usually) lower value.
Reduce driving sound volume (WITHOUT changing the function sounds) for DIESEL engines:
Here again, reducing the values in the CV’s #275, #276, #283 and #286 results in a lower volume for
the driving sounds.
In contrast to steam engines the values in these 4 CV’s are the same or very close to each other because
diesel motors don’t react as much to load; as a precaution though, they should still be read
out separately.
Reduce driving sound volume (WITHOUT changing the function sounds) for ELECTRIC engines:
The same CV’s #275, #276, #283 and #286 on electric engines are most often used “only” for the
cooling fan (in some cases they are not used at all), but this may be handled differently from one
sound project to another.
However, the volume of the thyristor sound can be set through the CV's #293, #294, #295 and the
engine sound with #296 (see CV table for detailed descriptions). If necessary read out the current
values of these CV's and replace them with smaller values.