Each source section should contain SET NAMES query like this:
Code:
source DBSource
{
type = mysql
#####################################################################
## SQL settings (for 'mysql' and 'pgsql' types)
#####################################################################
sql_host = " . $vBSphinxSearchConfig->dbservername . "
sql_user = " . $vBSphinxSearchConfig->dbusername . "
sql_pass = " . $vBSphinxSearchConfig->dbpassword . "
sql_db = " . $vBSphinxSearchConfig->dbname . "
sql_port = " . $vBSphinxSearchConfig->dbport . " # optional, default is 3306
sql_query_pre = SET NAMES cp1251
sql_query_pre = SET SESSION query_cache_type=OFF
}