[support] Solr search and custom filters

[amandil 001]

Hallo, I want to change the default sorting order of a pre-populated
Solr search page (the option "Show enabled facets' blocks in their
configured regions and first page of all available results" under
"Behavior on empty search" of the Advanced Search Options.
I thought the solution would be setting a custom filter but I cannot
find the right syntax: I tried everything from
"solrsort=ds_created:desc" to "sort=created:desc" and all the variants
between... but I failed... Anyone may help me please?

Thanks,
Amandil